FINAL REPORT FARMING FOR WILDLIFE: EFFECTS OF FLOODING, FORAGE HARVEST, AND

GRAZING ON SOIL PROPERTIES AND WEED ABUNDANCE ON AGRICULTURAL FIELDS IN THE SKAGIT RIVER DELTA, WA

Prepared by: Gary L. Slater John D. Lloyd

Ecostudies Institute P.O. Box 703

Mount Vernon, WA 98273

For: The Nature Conservancy

410 North 4th Street Mount Vernon, WA 98273

January 2010

Ecostudies Institute committed to ecological research and conservation

SUGGESTED CITATION: Slater, G.L. and J.D. Lloyd. 2010. Farming for wildlife: effects of flooding, forage harvest, and grazing on soil properties and weed abundance on agricultural fields in the Skagit River delta. Final Report to The Nature Conservancy, Seattle, WA

ACKNOWLEDGEMENTS

Funding for this project was provided by grants from Packard Foundation, Washington Ag Pilot Projects, and National Fish and Wildlife Foundation to The Nature Conservancy. The authors are grateful to Julie Morse, Roger Fuller, and Sarah Hamman of The Nature Conservancy for providing useful suggestions that improved the quality of this report. Special thanks to Alan Yoder of Wilbur-Ellis who assisted with soil sampling collection and with interpretation of soil reports, and provided assistance in vegetation identification. Finally, we acknowledge the farmers who were involved in this project, Serena and Dave Hedlin, Alan Mesman, and Gail Thulen.

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TABLE OF CONTENTS

Suggested Citation: ............................................................................................................. 2 Acknowledgements............................................................................................................. 2 Table of Contents................................................................................................................ 3 Index of Tables ................................................................................................................... 3 Index of Figures .................................................................................................................. 4 Abstract ............................................................................................................................... 6 Introduction......................................................................................................................... 7 Methods............................................................................................................................... 9

Site description................................................................................................................ 9 Study description ............................................................................................................ 9 Sampling description .................................................................................................... 10 Statistical methods ........................................................................................................ 12

Results............................................................................................................................... 13 Discussion......................................................................................................................... 15 Research Needed............................................................................................................... 21 Literature Cited ................................................................................................................. 22 Tables................................................................................................................................ 25 Figures............................................................................................................................... 30 Appendix A....................................................................................................................... 46

INDEX OF TABLES Table 1. Size of fields (ha) on three farms during the pre-treatment period. .................. 25 Table 2. Sampling schedule of Farming For Wildlife project.......................................... 25 Table 3. List of physical, chemical, and biological soil properties sampled during the study and descriptions of their general function and importance. .................................... 26 Table 4. Mean frequency of occurrence (+ S.E.) for the most common non-cropplant species recorded on treatment fields during the final sampling period (Spring 2009). Species with <0.01 mean frequency of occurrence in all treatment fields are not included............................................................................................................................................ 27 Table 5. Results of linear mixed models (p-values) and mean values (95% CI) during the spring 2009 sampling period for three plant groups and reed canarygrass under three treatments on three privately owned farms on the Skagit River delta, WA. .................... 27 Table 6. Model information and summary results (p-values) of linear mixed models for soil properties collected on three privately-owned farms on the Skagit River delta. ....... 28 Table 7. Size of flooded fields fields (ha) on three farms during the pre-treatment period............................................................................................................................................ 29

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INDEX OF FIGURES Figure 1. Map of the three privately-owned farms on the Skagit River delta, WA, participating in the study................................................................................................... 30 Figure 2. Map of farming practice treatments on the Hedlin and Mesman farm (left) and the Thulen farm (right)...................................................................................................... 31 Figure 3. Mean non-crop species frequency of occurrence (95% CI) on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods....... 32 Figure 4. Reed canarygrass frequency of occurrence (95% CI) on flooded, forage harvest, and grazed treatments of three privately owned farms on the Skagit River delta sampled from Winter 2006 to Spring 2009. Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. .............................................................................. 33 Figure 5. Mean crop species frequency of occurrence (95% CI) on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta. Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. .................................................................. 34 Figure 6. Mean wetland species frequency of occurrence (95% CI) on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately-owned farms on the Skagit River delta. Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. .................................................................. 35 Figure 7. Mean pH (95% CI) found on transects on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. .............................................. 36 Figure 8. Mean sum nitrogen (95% CI) found on transects on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic. ......................................................... 37 Figure 9. Mean ammonium (95% CI) found on transects on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic. ................................................................................. 38 Figure 10. Mean nitrate (95% CI) found on transects on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic. ................................................................................. 39 Figure 11. Mean boron (95% CI) found on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic. ................................................................................................... 40

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Figure 12. Mean iron (95% CI) found on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic. ....................................................................................................................... 41 Figure 13. Mean manganese (95% CI) found on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. Red index line indicates the level where manganese is considered excessive for the region. ....................................... 42 Figure 14. Mean yeast and mold (log transformed; + 95% CI) found on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. CFU/gdw = Colony forming units/gram dry weight sample. ........................................... 43 Figure 15. Map of flooded plots on the flooded treatment field on the Thulen farm (top left), Hedlin farm (bottom left), and Mesman farm (bottom right). ................................. 44 Figure 16. Total area of flooded treatment field and the area of flooded habitat in the 0-15cm and >15 cm water depths on three farms in the Skagit River delta. ....................... 45

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ABSTRACT This report details the results of a 3-year experimental study investigating the effects of flooding to create temporary wetlands on agricultural fields in comparison to two traditional crop-rotation practices, forage harvest and grazing. The study examined the response of physical, chemical, and biological soil properties, and weed abundance, all measures of economic importance to farmers, on 3-privately owned farms in the Skagit River delta of Washington. Sampling was conducted three times a year corresponding to major cycles of the growing season: spring, fall, and winter. Pre-treatment sampling period was initiated in spring 2006 and treatments were applied between the spring 2007 and fall 2007 sampling period. Observed increases in plant available nitrogen on the flooded treatment provide the best quantitative evidence of a benefit to flooding. Although not significant, mean plant available nitrogen during the last sampling period was approximately 35 lbs/acre higher on the flooded treatment than the grazed or forage harvest treatment. The two components of plant available nitrogen, ammonium and nitrate, differed significantly among treatments. Ammonium increased and nitrate decreased on the flooded treatment, both responses expected with anaerobic soil conditions. The behavior of nitrogen as fields revert to aerobic conditions will ultimately determine the true benefit of flooding to farmers. Decomposition of the wetland vegetation on the flooded treatment may also lead to increased nutrient inputs, particularly of nitrogen, compared to the other treatments. Cattail, the most abundant native wetland species on the flooded treatment, is a nitrogen fixer that produces large amounts of biomass. Incorporating this biomass into the soil may present challenges for a farmer, but doing so should contribute substantial nutrients that would become available to a subsequent crop following decomposition. A reduction in soil pH, a significant concern by farmers, was not observed in this study. Flooding maintained weed species at levels of abundance similar to the two traditional agricultural practices, indicating it was equally effective at weed suppression as forage harvest and grazing. However, reed canarygrass, an invasive exotic wetland species, colonized a large proportion of the flooded field at one farm. Reed canarygrass is an aggressive plant in wetlands, generally considered a threat to wetland ecosystem. We suspect that a flood event early in the study dispersed seeds and treatment application provided ideal conditions for germination. The presence and abundance of reed canarygrass, or other exotics of wetland ecosystems, adjacent to agricultural lands should be evaluated when considering the use of flooding as part of a crop rotation. Results from this study suggest that the creation of temporary wetlands appears to be a viable alternative to grazing and forage harvest practices within a crop-rotation program in the Skagit River delta. However, monitoring through the transition from anaerobic to aerobic conditions and cropping preparation, will be needed to fully evaluate the effect of flooding.

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INTRODUCTION

Agricultural ecosystems generally are species-poor and greatly simplified relative

to the natural ecosystems that they replace. Agricultural lands are also widespread and

common, by some estimates accounting for approximately 14% of global land area

(Ramankutty and Foley 1998), and will continue to expand rapidly (Tilman et al. 2001,

Green et al. 2005). As such, agriculture is a leading cause of biodiversity loss

(McLaughlin and Mineau 1995, Green et al. 2005), and managing agricultural lands to

provide habitat for non-crop plants and animals is therefore a key component of efforts to

conserve global biological diversity (Scherr and McNeely 2008).

Management practices that create habitat for plants and wildlife have been

successful in some agricultural settings. For example, retaining patches of natural habitat

amidst agricultural fields (Green et al. 2005), growing wetland crops to benefit waterbirds

(Czech and Parsons 2002), or managing crop margins to benefit grassland birds (Vickery

et al. 2002), have proven beneficial to wildlife, as have many of the practices associated

with organic farming (Chamberlain et al. 1999, Freemark and Kirk 2001). The economic

consequences of these practices are rarely evaluated, yet agricultural practices that

improve biological diversity but ignore economic factors important to farmers (e.g., crop

yield or soil conditions) will not be widely adopted, and therefore offer little value in

efforts to conserve biological diversity.

The creation of temporary wetlands on agricultural fields as a component of a

crop-rotation program has been proposed as an approach for increasing biological

diversity while maintaining or increasing economic yields on agricultural lands (Shennan

and Bode 2002). At Tule Lake National Wildlife Refuge, California, agricultural fields

were flooded on a three-year rotation to create temporary breeding and stopover habitat

for waterbirds. Farmers using these fields following the wetland rotation reported

excellent crop yields, improved soil fertility conditions, and decreased pests (Shennan

and Bode 2002). Although promising, the actual costs and benefits of wetland rotations

for farmers have not yet been fully quantified, and thus the true efficacy of integrating

temporary wetlands into a crop-rotation schedule remains largely unknown. Integrated

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studies that examine the economic and ecological outcomes of applying wetland rotations

are needed (Perrings et al. 2006).

In this study, we addressed these information needs by evaluating ecological and

economic effects of flooding farm fields to create temporary wetlands. We evaluated the

effects of flooding in comparison to two traditional practices commonly included in a

crop-rotation schedule, grazing and forage harvest. In a companion report, we details the

effects of flooding agricultural fields on shorebirds and soil invertebrates; in this report,

our objective was to quantify differences in soil properties and weed abundance, two

measures of economic importance to farmers, under these three treatments. Crop

rotations that improve soil conditions will be favored by farmers because they should

produce higher yields and require fewer applications of costly soil amendments.

Although many soil properties are important to farmers, the amount of three

macronutrients - nitrogen, potassium, and phosphorous - are especially key because they

limit plant growth and reproduction in most soils. Weed abundance is of economic

importance because weeds compete with crop plants, lowering yields and in severe cases

requiring the application of costly controls, such as herbicides. Crop rotations that

suppress weeds will be favored by farmers.

We conducted this study in the Skagit River delta of Washington. Prior to Euro-

American settlement, the Skagit River delta was an integrated complement of tidal,

nontidal, and riverine wetland habitats, comprising approximately 54% (18,000 ha) of the

total land area of the river delta (Collins 2000). Conversion of these fertile wetlands to

agricultural and other uses during the late 1800's and early 1900's eliminated most

estuarine wetlands and all non-tidal freshwater wetlands (Collins and Montgomery 2001),

and had a significant negative impact on wildlife communities, most notably migratory

birds and salmon (Ball et al. 1989, Simenstad and Cordell 2000). With agriculture both a

significant contributor to biodiversity losses and an important economic driver in the

region, conservation organizations and the agricultural community are working together

to identify and implement biodiversity farming practices. The conservation issues faced

by stakeholders are representative of problems faced in other agricultural regions of the

world; consequently, the Skagit River delta is a model system for studying how to

integrate biodiversity conservation into economically viable farm management.

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METHODS

Site description

The Skagit River delta (48° 23'N, 122° 27'W) is approximately 32,670 ha in

extent and contains the largest river flowing into Puget Sound. The alluvial soils of the

delta have provided fertile ground for agriculture, which is the number one industry in the

region. With 90 crops grown on ~24,000 ha of agricultural lands, over 300 million

dollars of agricultural products are produced annually (WSU Skagit County Extension

2008). This study was conducted from spring 2006 to spring 2009 on fields at three

privately owned farms: the Hedlin farm (20.8 ha), Mesman farm (28.3 ha), and Thulen

farm (26.9 ha), on the Skagit River delta, WA (Fig 1). Soil type on all fields was

classified as Skagit silt loam, consisting of silt loam, silty clay loam, and a small amount

of very fine sandy loam; moist bulk density of Skagit silt loam ranges from 1.15-1.30g/cc

(NRCS 2009). In the growing season prior to this study, fields were planted in pumpkins

(Hedlin), a combination of cucumbers and potatoes (Mesman), and potatoes (Thulen).

Study description

Each farm contained three adjacent fields. At the beginning of the study, all fields

were planted to a cover crop mix of orchardgrass (Dactylis glomerata), ladino/white

clover (Trifolium repens), and annual and perennial ryegrass (Lolium sp.). The pre-

treatment sampling period was initiated on the Hedlin farm in spring 2006 and on the

other two farms in winter 2006-2007. On the Hedlin farm, fields were reseeded in some

places during the spring 2007 pre-treatment period when the cover crop was damaged

due to extended flooding that occurred in November 2006. On the Thulen farms, fields

were reseeded in some places during the spring 2007 pre-treatment period when the cover

crop was damaged due to standing water and waterfowl grazing. During the pre-

treatment period, the cover crop was regularly mowed. The size of pretreatment fields

ranged from 5.3 – 11.7 ha (Table 1). Following the pre-treatment period each field

received one of three experimental treatments: 1) harvest of forage for silage or hay; 2)

livestock grazing; and 3) year-round flooding (Fig 2). Treatments were applied between

the spring 2007 and fall 2007 sampling period, except for the grazed treatment on the

Hedlin Farm which was applied following the fall 2007 sampling period (Table 2).

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The management schedule for treatments was developed in participation with

farmers to insure that management targets were achievable and, for the forage harvest and

grazed treatments, reflected traditional practices. The forage harvest treatment consisted

of harvesting the cover crop for hay or silage throughout the growing season (April-

October). On the grazed treatment, livestock were placed on the field as early as possible

(April-May) and removed after the growing season when field conditions became too wet

for livestock; if needed, the field was hayed early in the growing season. To flood fields,

farmers built berms and used topography to hold water. Water was pumped from adjacent

ditches or other freshwater sources. The management target for the flooded treatment was

to flood the baseline field to the largest extent possible. Farmers were requested to pump

water on the fields when standing water was reduced by 50% of the high water mark, and

flooding was maintained for the duration of the treatment period.

On all farms the flooded area consisted of multiple flooded plots that when

combined were smaller than the baseline field size. We considered the boundary of the

flooded treatment as the line where vegetation changed and soil was saturated due to the

flooding. Upon application of the flooded treatments, all sampling was conducted within

this boundary. Treatments were not applied randomly due to logistical considerations; the

flooded treatment fields were typically placed on low-lying fields and grazed treatment

fields were chosen based on access to electricity for fencing.

Sampling description

Data on vegetation and soil were collected on each of the nine treatment fields

three times annually corresponding to major cycles of the growing season: spring (early

growing season; April-May), fall (late-growing season; August-September), and winter

(non-growing season; December-February). Frequency of occurrence of plant species

were determined from six, 30-m transects randomly established in each field; 2-4

additional transects were conducted on flooded treatment fields throughout the treatment

period due to the low abundance of vegetation on the flooded treatment. At every 0.5

meter, a pole was placed along the tape and each species that touched the pole was

recorded and the height where it touched the pole was recorded. If no plant touched the

pole, the location was categorized as bare ground. On the flooded treatment only standing

vegetation above the water was counted. We lumped plants into one of three groups: crop

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(any of the three cover-crop species), non-crop species (those species that were not the

crop or native wetland species), and native wetland species. We estimated the mean

frequency of occurrence for each group for each of the nine fields during each sampling

period. We considered the frequency of non-crop species as an index for weed

abundance, rather than relying on a single species or particular group of species, such as

broadleaf annuals, because only three non-crop species reached a mean frequency of

occurrence >1% within any sampling period. Non-crop species may also be a good

measure of weed abundance because all species produced seeds that could contribute to

the seedbank and compete with future crops.

We measured a broad spectrum of physical, chemical, and biological soil

properties that farmers deemed important economic indicators of soil quality and

potential crop yield (Table 3). Soil properties play many roles in the growth and survival

of crop plant species. Arguably, one of the most important groups of soil properties to

farmers in this study is the primary macronutrients: phosphorous, potassium, and

nitrogen. These nutrients are significant because they have a strong influence on plant

growth and reproduction, are often limiting in soils, and are expensive as soil

amendments. Other soil properties considered of high importance in this study were

organic matter and soil pH. Organic matter provides habitat and nutrients for soil

organisms, improves water and nutrient holding capacity, and serves as a source of

nutrients to plants upon mineralization. Farmers in the Skagit River delta expend

considerable energy directing water off of agricultural fields in the winter due to concerns

that flooding decreases soil pH. Reduced soil pH is a problem requiring the application

of lime to raise pH levels to acceptable levels for farming. On each field, a minimum of

15 core sub-samples (core = 2 cm; depth = 20 cm) were collected from locations

randomly generated prior to sampling with ArcGIS (Hawths Tools). If sampling

locations landed in areas that appeared unrepresentative of the treatment, such as near

field entrances or water troughs, the location was moved to the closest unmodified area.

Subsamples were thoroughly mixed to obtain a composite representative sample for each

field and split for use in soil fertility and soil microbiology analyses. Soil analyses were

conducted by Soiltest Farm Consultants, Inc., Moses Lake, WA (physical and chemical)

and BBC Laboratories, Tempe, AZ (biological).

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We outlined the flooded treatment boundary using location data collected with a

GPS unit and determined the area within the flooded treatment using GIS software

(ESRI, Redland, CA). Within the flooded treatment, water depth was measured from > 15

randomly generated locations and > 5 locations on the boundary edge for each flooded

plot. Using the Spatial Analyst module in ArcMap 9.2, water-depth data were

interpolated by interdistance weighting using the 12 closest points within a 100-m radius

and with the closest points receiving the highest weight possible. We then determined the

areas of flooded habitat in each of two depth categories (cm): 0 – 15.0, and >15.1. We

collected water-depth data during periods that we deemed to reflect average water levels

during the sampling period, avoiding periods immediately after farmers had pumped

water onto fields or when water needed to be pumped onto fields.

Statistical methods

We tested the effect of treatment on individual vegetation and soil variables using

generalized linear mixed models (glmmPQL and lmer functions in R; R Core

Development Team 2008). Treatment and sampling period were considered main effects

in each model along with the treatment*sampling period interaction term. Each farm was

considered one replicate. Treatments were not randomly applied, and thus apparent

differences among fields subjected to different treatments may have reflected pre-existing

differences. As such, the appropriate test for examining treatment effects is the

significance of the treatment*time interaction (Underwood 1994). To address the issue

of repeated measures (i.e., lack of independence among samples taken on the same field),

we included field as a random effect in all of our models. Where possible, we applied

transformations to meet the assumptions of normally distributed errors and constant

variance. We evaluated the assumption of normality via normal probability plots and the

assumption of homoscedacity with plots of residuals versus fitted values. In situations

where assumptions of normal distributions were not met or the normal distribution was

not appropriate for the data (e.g., counts), we evaluated other error distributions as a

component in the model. The most appropriate distribution for the data was determined

using theoretical considerations (e.g., that counts typically conform to a Poisson or

negative-binomial distribution) and through examination of quantile plots of standardized

residuals and plots of residuals versus predicted values. Only data from the period with

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full replication across all three farms were used in the analysis (Winter 2006-07 to Spring

2009); thus, there were no pre-treatment data for the Fall (late-growing season) sampling

period. We evaluated the effect size of different treatments through means and 95%

confidence intervals. To insure that confidence intervals of frequency of occurrence

means were bound by 0 and 1.0, we used the method by Agresti and Coull (1998) for

binomial proportions. To insure that confidence intervals of other variable means did not

cross 0, we calculated means and confidence intervals of log-transformed values and then

back transformed values, a technique that is appropriate for log-normal data (Limpert et

al. 2001), such as the soil properties data collected in this study.

RESULTS

We detected 41 plant species on vegetation surveys, and most species occurred

infrequently. Only two species other than the crop, reed canarygrass (Phalaris

arundinacea) and cattail (Typha latifolia), had frequency of occurrence over 5% on fields

during the final treatment period (Table 4). Mean frequency of occurrence of non-crop

species, our index of weed abundance, did not differ among treatments (Table 5, Fig 3)

and values varied over time and among farms. In the last sampling period, non-crop

frequency of occurrence was highest on the flooded (mean = 0.28; range = 0.08 – 0.58)

and grazed (mean = 0.26; range = 0.02 – 0.59) treatments, compared to the forage harvest

treatment (mean = 0.08; range = 0.02 – 0.21). Reed canarygrass was the most abundant

non-crop species, but was almost exclusively limited to the Hedlin farm (Fig 4). Cover-

crop frequency of occurrence differed significantly among treatments with average means

across the treatment period on the forage harvest and grazed treatments 500% higher than

on the flooded treatment (Table 5, Fig 5). The frequency of occurrence of native wetland

species was significantly higher on the flooded treatment than on the forage harvest and

grazed treatments (Table 5, Fig 6). The mean height of wetland plants was highest in the

fall 2008 sampling period (mean = 1.0 m; range = 0.26 – 1.15 m).

Tables of values for soil properties for each, farm, treatment, and sampling period

are located in Appendix A. Only one of the physical soil variables, percent soil moisture,

differed among the treatments (Table 6). During the treatment period, mean percent soil

moisture was higher on the flooded treatment (0.49, CI= 0.44-0.53) than on the forage

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harvest (0.38, CI = 0.34-0.42) or grazed treatments (0.44, CI = 0.36-0.40). Although

farmers were concerned that pH values would decline on the flooded treatment, pH did

not differ among treatments (Fig 7).

Many of the chemical soil properties varied significantly over the course of the

experiment, but only four variables - ammonium, nitrate, boron, and iron - differed

significantly among treatments; manganese showed a marginal treatment effect (Table 6).

In all cases where variables differed due to the treatment, means indicated that

differences were due to changes on the flooded treatment fields. In general, the treatment

patterns were relatively consistent among the three farms, although at times the

magnitude varied. For example, the effect of flooding on ammonium was more evident

on the Mesman farm.

Plant available nitrogen did not differ among treatments (Fig 8); however, during

the last sampling period mean nitrogen was nearly 185% higher on the flooded treatment

(69 lbs/acre) than the forage harvest (37.2) or grazed (35.2) treatments. The two

components of plant available nitrogen, ammonium and nitrate, responded differently to

the treatments. Mean ammonium in the last sampling period was over 850% higher on

the flooded treatment than the forage harvest and grazed treatments (Fig 9), whereas

mean nitrate was 450% lower on the flooded fields (Fig 10).

Mean values of two micronutrients, boron and iron, were significantly higher on

the flooded treatment, with values in the last sampling period 200% higher than on the

other treatments (Fig 11, Fig 12). Values of iron were found at levels considered high

(Soiltest Labs, Moses Lake, WA) in the final sampling period on the flooded treatment

fields on the Hedlin and Thulen farms and on all treatment fields on the Mesman farm.

Manganese levels on the flooded treatment were exceptionally high on the Hedlin and

Thulen farms compared to both other treatments, but not on the Mesman farm (Fig 13).

Except for the abundance of yeasts and molds, soil biological communities and

their species richness indexes did not differ among the treatments (Table 6). Yeasts and

molds were less abundant on the flooded treatment than the two traditional treatments

(Fig 14).

The total area of the flooded treatment varied by farm, as did the number of

flooded plots on each farm. The Hedlin farm had the largest flooded area (two plots;

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range: 6.9-7.2 ha), followed by the Mesman farm (two plots; 4.4 – 5.3), and the Thulen

farm (five plots; 1.7 – 2.5; Table 7, Fig 15). On the Mesman and Thulen farms, the

amount of area in the 0-15 and >15 cm water depth categories was relatively constant

throughout the treatment period, with both farms having a higher proportion of the field

in the 0-15 cm depth (Fig 16). The Hedlin farm had a much higher proportion of deep

water (>15 cm) than the 0-15 category during the first year of treatments. Beginning in

the fall 2008 sampling period, the proportion of area between the two depth categories

was relatively similar. With the exception of plots TH2 and TH3 on the Thulen farm,

water depth changes were relatively gradual. Both TH2 and TH3 dewatered quickly

following flooding, usually within 2 weeks, and thus keeping these plots flooded during

the course of the sampling period often proved difficult. These plots were not included in

the spring 2009 sampling period because they were unable to be flooded because water

was inaccessible.

DISCUSSION

This study found that the creation of temporary wetlands as a component of a

crop rotation schedule may prove economically beneficial to farmers in the Skagit River

delta compared to two other traditional crop rotation practices, grazing and forage

harvest. The main benefit of flooding appears to be improvement in soil fertility through

increases in the amount of plant available nitrogen, an important plant nutrient often

limiting in soils. While we detected no net benefit to flooding in the form of weed

suppression, flooding maintained weed species at levels of abundance similar to the two

traditional agricultural practices.

Observed increases in plant available nitrogen on the flooded treatment provide

the best quantitative evidence of a benefit to creating temporary wetlands on agricultural

fields as part of a crop rotation program. Plant available nitrogen increased on all

treatments as soils recovered from previous cropping and no significant difference was

found among treatments. However, mean plant available nitrogen was generally higher

on the flooded treatments throughout the treatment period and during the last sampling

period was approximately 35 lbs/acre higher on the flooded treatment than the grazed or

forage harvest treatment. Although lacking statistical significance, such a difference

15

would translate to a potential economic benefit from a farmer’s perspective. Nitrogen is

often the most limiting nutrient for plant growth and is generally the most commonly

applied nutrient to crops (Dordas 2008). Increased soil nitrogen in the flooded treatment

should lead to either increased crop yields or a reduction in costly nitrogen fertilizer for

subsequent crops.

The source of additional nitrogen is unclear. The two components of plant

available nitrogen, ammonium and nitrate, differed among treatments and those

differences were attributable to the anaerobic soil conditions found on the flooded fields.

Soil concentration of ammonium increased and soil concentration of nitrate decreased on

the flooded treatment, both responses expected with anaerobic soil conditions (Reddy and

Patrick 1975, Lockaby et al. 1996, Unger et al. 2009). Under flooded conditions,

ammonium can be produced through ammonification (conversion of organic nitrogen into

ammonium) and nitrate reduction (conversion of nitrate to ammonium), and nitrate can

be lost through nitrate reduction and denitrification (conversion of nitrate into N2;

(Baldwin and Mitchell 2000, Unger et al. 2009). With a negative charge, nitrate is also

highly mobile and, unlike ammonium, can move downward in the soil and be lost

through leaching under flooded conditions. We suspect nitrate reduction was the primary

process through which ammonium increased and nitrate decreased and that additional

nitrogen was likely mineralized from organic sources through ammonification. We did

not sample soil at deep depths to evaluate the loss of nitrate to leaching.

Decomposition of the wetland vegetation built up on the flooded treatment may

also lead to increased nutrient inputs, particularly of nitrogen, compared to the other

treatments. Mean vegetation height on the flooded treatment approached 1 m on the

Hedlin and Mesman farm by the fall 2008 sampling period, a year following treatment

application. Although incorporating this biomass back into the soil may present

challenges for the farmer, doing so should contribute substantial nutrients into the soil

that would become available to a subsequent crop following decomposition. Cattail, the

most abundant native wetland species on the flooded treatment, is a nitrogen fixer that

produces large amounts of biomass. Bieboer (1984) estimated that 8.2% of the total

nitrogen present in the standing crop of cattail is a result of nitrogen fixation. Thus, its

return to the soil serves as a potential significant source of nitrogen.

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Any benefit related to the decomposition of native wetland vegetation will vary

with the amount of vegetation that colonizes the flooded treatment. In this study, the

response of native wetland vegetation varied by farm with frequency of occurrence

values in the last sampling period ranging from 0.06 (Thulen farm) to 0.15 (Mesman

farm) to 0.29 (Hedlin farm). Variation in the amount of wetland vegetation may reflect

how well the flooded treatment was applied. The flooded treatment prescription was not

as well maintained on the Thulen farm as the other farms. The extent of the flooded area

on the Thulen farm often fell lower than 50% of the maximum flooded extent, especially

between sampling periods. Variation in native wetland vegetation may also reflect

differences in the soil seed bank. The Thulen farm was the farthest site from the estuary,

while the Hedlin farm was adjacent to the Skagit River. Fields on the Hedlin farm also

were covered with water for over two weeks during a flood event in November 2006 and

that event likely transported and dispersed seeds of native wetland species onto the

flooded field.

A reduction in soil pH due to long-term flooding was a significant concern by

farmers, but was not observed in this study. Skagit silt loam soils are generally poorly

drained and farmers in the area expend considerable energy removing water through

ditching, particularly during the non-growing season when precipitation and the water

table is high. Monitoring soil pH during the transition to aerobic conditions will be

important to evaluate the long-term effects of flooding.

Our results indicate that flooding was similarly effective as forage harvest or

grazing in minimizing the abundance of weeds. Although a direct benefit was not

detected, flooding could be considered an alternate practice to these traditional measures

with respect to weed suppression within a crop rotation. Cover crops can have a positive

effect on weed suppression and control weeds through competition exerted by the crop,

preventing the emergence of weeds, and suppressing weed seedlings (Shrestha et al.

2002, Campiglia et al. 2009). On the flooded treatment, the cover crop mostly

disappeared due to the application of water, creating large unvegetated areas. Weeds on

the flooded treatment were likely suppressed by water depth and, perhaps, by competition

with wetland species where they occurred. Most weeds on the flooded fields became

established in areas where water depth was low or in areas where soil became exposed,

17

such as the edges of the flooded plots. Although native wetland plants on flooded fields

also produce large quantities of seeds, their ability to germinate following drainage and

tilling should be diminished as conditions necessary for germination (e.g., saturated soils)

will be absent.

Several notes of caution are warranted regarding the effect of flooding as a

potential benefit to farmers. First, with the large imbalance between the two sources of

plant available nitrogen, ammonium and nitrate, the behavior of nitrogen during the

transition period back to aerobic conditions will ultimately determine the actual benefit, if

any, of the flooding treatment to farmers. Loss of plant available nitrogen is a potential

concern as soils revert to aerobic conditions. Nitrification (conversion of ammonium to

nitrate) is a biological process that will proceed quickly in warm, moist, and well-aerated

soils, but how nitrate responds is unclear. It could remain in a form available for plants,

be lost to atmospheric nitrogen, or leach into subsurface soils. Leaching is of particular

concern during the winter and spring when precipitation is high in the Pacific Northwest.

In addition to leaching, loss of nitrogen through volatization of ammonia gas during

tilling is also a concern. Because both nitrification and ammonia volatization occur more

rapidly under warmer conditions, tillage of the flooded field after drainage should

probably be delayed until soil temperatures are below 50° F to reduce the potential for

nitrogen loss.

Most other soil properties remained similar among treatments, except for soil

concentrations of iron and manganese, which increased on the flooded field. Under

flooded conditions, soil chemistry is strongly influenced by chemical reduction reactions,

which promote dissolution of iron and manganese oxides from the soil (Baldwin and

Mitchell 2000, Morales et al. 2002). The strength of these reactions appeared to differ

among the three farms. Iron was found at levels considered high (by Soiltest Labs) on all

flooded treatments. Manganese increased on the Thulen and Hedlin farm but not the

Mesman farm; however it was only found at high levels on the Hedlin farm. In the

Skagit River delta, excessive levels of iron and manganese are generally not considered a

significant problem to farmers. Availability of both micronutrients to plants is mediated

through soil pH and problems are most common when pH <5.0. Soil pH in this study

varied between 5.5 and 7.0.

18

The lack of significant changes in the biological community was surprising given

the anaerobic condition and the response of ammonium and nitrate under the flooded

treatment. Aerobic and anaerobic bacteria and fungi are important decomposers in the

nitrogen cycle, including the processes of ammonification and denitrification under

anaerobic conditions. The absence of changes in the biological community supports the

notion that increases in ammonium and decreases in nitrate were primarily a result of

nitrate reduction. The only soil microfauna that responded to treatments were yeast and

molds, which were found at lower abundance on the flooded treatment. Yeast and molds

are thought to be important in breaking down organic compounds, stabilizing soil

aggregates, and controlling plant disease. Continued monitoring of these communities

through the draining and tilling cycle in preparation for the growing season may provide

additional information related to the effect of the flooding treatment.

A second note of caution regarding the use of flooding was the colonization of

reed canarygrass, an invasive exotic wetland species, over a large proportion of the

flooded field at that Hedlin farm. Reed canarygrass is an aggressive plant in wetlands,

generally considered a threat to wetland ecosystems (Apfelbaum and Sams 1987). Its

vigorous growth inhibits and eliminates native wetland plant species and dense stands

have little value for wildlife. Reed canarygrass occurs on saturated soils, but does not

tolerate extended period of flooding. On the Hedlin farm, reed canarygrass became

established on all treatment fields, but formed a near monoculture on a section of the

flooded treatment where water depth was low (Plot T1). The flooded field of the Mesman

farm was the only other field where reed canarygrass was found, and colonization did not

occur there until the second growing season following flooding. Reed canarygrass was

present in drainage ditches along field edges of the Mesman and Hedlin farms. We

suspect that the flood event at the Hedlin farm in November 2006 likely dispersed seeds

of reed canarygrass across the fields, and subsequent flooding due to treatment

application provided ideal conditions for germination. The large stand of reed

canarygrass on the flooded field of the Hedlin farm will likely present challenges for

cropping on this field in subsequent years. The Hedlin farm is primarily organic.

Without herbicides, removal of reed canarygrass is difficult because even after

mechanical treatment the species can regrow rapidly from rhizomes and seeds that remain

19

in the soil. The presence and abundance of reed canarygrass, or other exotics of wetland

ecosystems, adjacent to agricultural lands should be evaluated when considering the use

of flooding as part of a crop rotation. If reed canarygrass becomes established, one

management option to consider is immediate draining and mowing to reduce the potential

for long-term establishment. Containing reed canarygrass in these situations is especially

important where managed or intact wetlands are nearby due to the potential for seed

dispersal from the agricultural wetland.

The final note of caution regarding the flooding treatment was that the application

of the flooded treatment upon the agricultural fields in this study was challenging because

it required the construction of large berms along field edges and regular pumping of

water onto fields. Variation in elevation and access to water appeared to be the major

factors in keeping fields flooded. The two farms (Hedlin and Mesman) that had

relatively level fields and a stable water source nearby were more successful in applying

the treatment to a larger proportion of their field and maintaining flooded conditions.

The Hedlin farm was also lower in elevation than both the Mesman and Thulen farm,

another factor that likely contributed to successful application of the flooded treatment.

The flooded field on the Thulen farm had the largest elevational changes over the field

due to the presence of historic slough beds. Large elevation changes on the field required

higher berms to hold water. To address this problem the farmer created multiple plots

that were small in size. The two plots that tended to dewater quickly, TH2 and TH3, were

situated on higher ground above the slough beds, while the other plots, which held water,

were in the slough bed. Although soil type was the same across all farms, local variation

in the amount of clay and sand may have also played a role in the ability of soils to hold

water. Water was also less accessible at the Thulen farm, with the closest drainage ditch

over 200 m away. During the summer and fall, this ditch often did not have enough

water to pump onto the fields. In general, maintaining flooded conditions during the

winter and spring was easier than in the fall because the water table was higher,

precipitation in the form of rain contributed water to the field without the need for

pumping, and cool weather reduced water loss through evaporation. For flooding to be

effectively implemented as a component of a crop rotation schedule, elevation, water

source, soil type, and climate need to be carefully evaluated prior to implementation.

20

In conclusion, the creation of temporary wetlands appears to be a viable

alternative to grazing and forage harvest practices within a crop-rotation program in the

Skagit River delta. Flooding of agricultural fields provided a benefit to farmers through

increases in nitrogen, while other important soil properties remained similar among

treatments. Flooding did not provide a direct benefit towards weed suppression but was

equally effective compared to grazing and forage harvest practices. Because this study

did not cover the transition from anaerobic to aerobic conditions and cropping

preparation, additional monitoring of weed abundance and soil properties on all

treatments will be needed to fully evaluate the effect of flooding. If soil and weed

conditions remain favorable on the flooded treatments, flooding should be considered a

viable alternative to existing crop–rotation practices. Flooding appears to offer potential

economic benefits to farmers while also yielding an ecological benefit in the form of

increased habitat for wetland-dependent species (See companion report).

RESEARCH NEEDED

• Continued monitoring of soil properties is critical during subsequent farm

management practices of drainage and tillage on treatment fields to fully evaluate the

costs and benefits of a flooded crop rotation in comparison with grazing and forage

harvest practices.

• Surprisingly, there was little response in the biological variables (counts of various

bacteria and yeasts and molds and associated indexes) measured in this study. The

laboratory used for analysis, BBC Labs, was recommended by the farmers involved

in the study and one of their suppliers. We suggest futures studies should consider

changing the attributes of the biological soil sampling based on recommendation from

soil microbiologists.

• Studies of soil biology are ideal for experimental approaches because they can be

conducted at small scales. In this study, treatments were conducted at scales large

enough to investigate the response of birds to treatments. Further research into the

effect of flooding on soil properties would be improved by conducting experiments

with smaller sampling units that would allow for greater ease in increasing

21

replication, and thus improve statistical power. Such an approach would also permit

additional investigations of localized interactions including water depth, algal growth,

and decomposition that would improve our understanding of nutrient fluctuations.

• Crop rotations are important to breaking pathogen cycles that survive in soils and

crop residue (Peters et al. 2003). Initial studies at Tule Lake National Wildlife

Refuge, California indicated that flooding depressed pathogens. Controlled studies

evaluating the use of flooding to reduce pathogens are needed to evaluate this

potential benefit.

• Additional studies on other soil types would improve our understanding of whether

the practice of incorporating a temporary wetland in a cropping schedule is beneficial

to farmers more generally. To our knowledge, this study represents the second

replicate suggesting that the application of temporary wetlands on farm fields

provides a benefit to farmers. However, further studies in other agricultural regions

will solidify this technique as a viable approach to biodiversity conservation on

agricultural lands.

• An economic analysis is needed to compare the tradeoffs between the costs of

establishing and maintaining flooded conditions on fields with the potential benefits

of reduced nutrient and herbicide inputs and standardized on crop yields.

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Apfelbaum, S. I. and C. E. Sams. 1987. Ecology and control of reed canary grass. Natural Areas Journal 7:69-74.

Baldwin, D. S. and A. M. Mitchell. 2000. The effects of drying and re-flooding on the sediment and soil nutrient dynamics of lowland river-floodplain systems: a synthesis. Regulated Rivers: Research & Management 16:457-467.

Ball, J., R. D. Bauer, K. Vermeer, and M. J. Rabenberg. 1989. Northwest riverine and Pacific coast.in L. M. Smith, R. L. Pederson, and R. M. Kaminski, editors. Habitat managment for migrating and wintering waterfowl in North America. Texas Tech University Press, Lubbock, TX.

Bieboer, D. D. 1984. Nitrogen Fixation Associated with Natural and Cultivated Stands of Typha latifolia L. (Typhaceae). American Journal of Botany 71:505-511.

Campiglia, E., R. Paolini, G. Colla, and R. Mancinelli. 2009. The effects of cover cropping on yield and weed control of potato in a transitional system. Field Crops Research 112:16-23.

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Chamberlain, D. E., J. D. Wilson, and R. J. Fuller. 1999. A comparison of bird populations on organic and conventional farm systems in southern Britiain. Biological Conservation 88:307-320.

Collins, B. D. 2000. Mid-19th century stream channels and wetlands interpreted from archival sources for three north Puget Sound estuaries. Report for Skagit River System Cooperative, LaConner, WA.

Collins, B. D. and D. R. Montgomery. 2001. Importance of archival and process studies to characterizing pre-settlement riverine geomorphic processes and habitat in the Puget lowland.in J. M. Dorava, D. R. Montgomery, B. Palcsak, and F. Fitzpatrick, editors. Geomorphic processes and riverine habitat American Geophysical Union, Washington, D.C.

Czech, H. A. and K. C. Parsons. 2002. Agricultural wetlands and waterbirds: a review. Waterbirds 25 (Special Publication 2):56-65.

Dordas, C. 2008. Role of nutrients in controlling plant diseases in sustainable agriculture. A review [electronic resource]. Agronomy for sustainable development 28:33-46.

Freemark, K. E. and D. A. Kirk. 2001. Birds on organic and conventional farms in Ontario: partitioning effect of habitat and practices on species composition and abundance. Biological Conservation 101:337-350.

Green, R. E., S. J. Cornell, J. P. W. Scharlemann, and A. Balmford. 2005. Farming and the Fate of Wild Nature. Science 307:550-555.

Limpert, E., W. A. Stahel, and M. Abbt. 2001. Log-normal distributions across the sciences: keys and clues. Bioscience 51:341-352.

Lockaby, B. G., A. L. Murphy, and G. L. Somers. 1996. Hydroperiod Influences on Nutrient Dynamics in Decomposing Litter of a Floodplain Forest. Soil Sci Soc Am J 60:1267-1272.

Morales, L. A., S. Vázquez, and A. Paz-González. 2002. Nutrient status on an acid soil as affected by lime amendments after flooding. Communications in Soil Science & Plant Analysis 33:3007.

NRCS. 2009. Soil resource report for Skagit County area. National Resource Conservation Service, United States Department of Agriculture.

Perrings, C., L. Jackson, K. Bawa, L. Brussaard, S. Brush, T. Gavin, R. Papa, U. Pascual, and P. De Ruiter. 2006. Editorial. Biodiversity in agricultural landscapes: saving natural capitol without losing interest. Conservation Biology 20:263-264.

Peters, R. D., A. V. Sturz, M. R. Carter, and J. B. Sanderson. 2003. Developing disease-suppressive soils through crop rotation and tillage management practices. Soil and Tillage Research 72:181-192.

R Core Development Team. 2008. R: A language and environment for statistical computing. R Foundation for statistical computing.

Ramankutty, N. and J. A. Foley. 1998. Characterizing patterns of global land use: An analysis of global croplands data. Global Biogeochemical Cycles 12:667-685.

Reddy, K. R. and W. H. Patrick. 1975. Effect of alternate aerobic and anaerobic conditions on redox potential, organic matter decomposition and nitrogen loss in a flooded soil. Soil Biology and Biochemistry 7:87-94.

Scherr, S. J. and J. A. McNeely. 2008. Biodiversity conservation and agricultural sustainability: towards a new paradigm of ‘ecoagriculture’ landscapes.

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Philosophical Transactions of the Royal Society B: Biological Sciences 363:477-494.

Shennan, C. and C. Bode. 2002. Integrating wetland habitat with agriculture. Pages 189-204 in D. L. Jackson and L. L. Jackson, editors. The farm as natural habitat: reconnecting food systems with ecosystems. Island Press, Washington, D.C.

Shrestha, A., S. Z. Knezevic, R. C. Roy, B. R. Ball-Coelho, and C. J. Swanton. 2002. Effect of tillage, cover crop and crop rotation on the composition of weed flora in a sandy soil. Weed research 42:76-87.

Simenstad, C. A. and J. R. Cordell. 2000. Ecological assessment criteria for restoring anadromous salmonid habitat in Pacific Northwest estuaries. Ecological Engineering 15:283-302.

Underwood, A. J. 1994. On Beyond BACI: Sampling Designs that Might Reliably Detect Environmental Disturbances. Ecological Applications 4:4-15.

Unger, I. M., P. P. Motavalli, and R.-M. Muzika. 2009. Changes in soil chemical properties with flooding: A field laboratory approach. Agriculture, Ecosystems & Environment 131:105-110.

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WSU Skagit County Extension. 2008. 2008 Skagit County Agriculture Statistics. Washington State University Skagit County Extension, Mt. Vernon, WA.

24

TABLES Table 1. Size of fields (ha) on three farms during the pre-treatment period.

Treatment Hedlin farm Mesman farm Thulen farm

Grazed 5.3 10.8 7.8 Forage Harvest 7.5 9.9 11.7 Flooded 8.0 7.6 7.4

Table 2. Sampling schedule of Farming For Wildlife project.

PRE-TREAMENT TREATMENT

Farm Spring 2006

Fall 2006

Winter 2006

Spring 2007

Fall 2007

Winter 2007

Spring 2008

Fall 2008

Winter 2008

Spring 2009

Hedlin Ba Ba B B Tb T T T T T

Mesman B B T T T T T T

Thulen B B T T T T T T B = Baseline; T = Treatment a No vegetation sampling was conducted in spring 2006 and fall 2006. b Except for the grazing field at the Hedlin Farm, which is treated as Baseline condition.

25

Table 3. List of physical, chemical, and biological soil properties sampled during the study and descriptions of their general function and importance. Physical Function

pH Organic Matter Electrical Conductivity Base Saturation Cation Exchange Capacity Percent Moisture

The physical properties of soil are important in a variety of ways including water holding capacity, nutrient availability, soil porosity/plant root growth. Soil pH is one of the most important soil properties because it regulates the availability of some nutrients (e.g., macronutrients tend to be less available in soils with low pH). Organic matter is also of high importance because it reflects available nutrients, provides nutrients to biological organisms, and increases water holding capacity.

Chemical Primary macronutrients Phosphorous Potassium Sum Nitrogen • Ammonium • Nitrate

These three macronutrients are the major nutrients for plants. They are usually lacking in soil because plants use large amounts for their growth and survival. Sum nitrogen (Plant-available nitrogen) is the sum of both ammonium and nitrate.

Secondary macronutrients Calcium Magnesium Sulfate

These three secondary macronutrients are usually sufficient in soils so that fertilization is rarely needed. Also, large amounts of Calcium and Magnesium are added when lime is applied to low pH (acidic) soils

Micronutrients Boron Copper Iron Manganese Sodium Zinc

Micronutrients are those elements essential for plant growth which are needed in only very small quantities. Most elements are usually sufficient in soils.

Biological Actinomycetes Actinomycetes Diversity Index Anaerobic Bacteria Anaerobic Bacteria Diversity Index Heterotrophic Bacteria Heterotrophic Bacteria Diversity Index Nitrogen Bacteria Nitrogen Bacteria Diversity Index Pseudomonads Pseudomonads Diversity Index Total Species Richness Index Yeast and Mold Yeast Diversity

Although less well understood than physical and chemical soil properties, high levels of biological activity in soils is often thought to be associated with improved soil quality and crop yields.

27

Table 4. Mean frequency of occurrence (+ S.E.) for the most common non-cropplant species recorded on treatment fields during the final sampling period (Spring 2009). Species with <0.01 mean frequency of occurrence in all treatment fields are not included. Treatment

Flooded Forage Harvest Grazed

Plant type Farma Mean S.E. Mean S.E. Mean S.E. Bluegrass (Poa annua) Annual H, M, T 0.03 0.02 0.01 0.00 0.04 0.03

Pineapple weed (Matricaria matricarioides) Annual T 0.00 0.00 0.00 0.00 0.02 0.02

Reed canarygrass (Phalaris arundinacea) Perennial H, M 0.20 0.19 0.04 0.04 0.09 0.09

Buttercup (Ranunculus sp.) Perennial H, M 0.00 0.00 0.00 0.00 0.04 0.04

Creeping fescue (Festuca rubra) Perennial H, T 0.00 0.00 0.01 0.01 0.03 0.03

Fescue (Festuca sp.) Perennial H, T 0.00 0.00 0.01 0.01 0.05 0.05

Cattail (Typha latifolia) Wetland H, M, T 0.08 0.04 0.00 0.00 0.00 0.00

Rush (Juncus sp.) Wetland H, M, T 0.05 0.04 0.00 0.00 0.00 0.00 a H = Hedlin, M = Mesman, T = Thulen

Table 5. Results of linear mixed models (p-values) and mean values (95% CI) during the spring 2009 sampling period for three plant groups and reed canarygrass under three treatments on three privately owned farms on the Skagit River delta, WA.

Results of linear mixed models Mean values (95% CI)

Model Factors Treatments

Treatment Time Treatment*Time Flooded Forage

Harvest Grazed

Non-crop (weed index) 0.81 0.11 0.44 0.28 (0.06-0.71)

0.08 (0.01-0.56)

0.26 (0.05-0.70)

Crop 0.18 <0.01 <0.01 0.03 (0.00-0.50)

0.81 (0.35-0.97)

0.80 (0.35-0.97)

Native wetland species 0.38 <0.01 <0.01 0.16 (0.02-0.63)

0.00 (0.00-0.47)

0.01 (0.00-0.47)

Reed canarygrass 0.87 0.09 0.47 0.20 (0.03-0.65)

0.05 (0.00-0.52)

0.09 (0.01-0.56)

28

Table 6. Model information and summary results (p-values) of linear mixed models for soil properties collected on three privately-owned farms on the Skagit River delta. Model Factor Soil Variables Distribution Transformation Treatment Time Treat*TimePhysical Bases Normal Log 0.52 0.02 0.38 Buffer pH Normal None 0.66 0.02 0.94 CEC Normal None 0.47 0.05 0.44 Est. EC Normal Log 0.86 0.92 0.91 Organic Matter Normal Arcsin-Square root 0.32 0.03 0.08 Percent moisture Normal Arcsin-Square root 0.52 <0.001 0.002 pH Normal None 0.99 0.16 0.25 Chemical Ammonium Normal Log 0.75 <0.001 0.02 Boron Normal Log 0.48 0.01 0.02 Calcium Normal Log 0.70 0.01 0.15 Copper Normal None 0.49 0.19 0.79 Iron Normal Log 0.73 <.01 0.03 Potassium Normal None 0.20 0.17 0.22 Magnesium Normal Log 0.93 0.60 0.46 Manganese Normal Log 0.94 <0.01 0.05 Sodium Normal Log 0.77 <0.01 0.11 Nitrate Normal Square root 0.61 0.09 0.002 Phosphorous Normal None 0.41 0.55 0.92 Sulfate Normal Log 0.68 0.92 0.53 Sum N (plant available) Normal Log 0.91 <0.01 0.51 Zinc Normal Log 0.85 0.87 0.98 Biological Actinomycetes Poisson Log 0.89 0.03 0.49 Actinomycetes Diversity Index Normal None 0.41 0.02 0.24 Anaerobic Bacteria Poisson Log 0.70 0.56 0.62

Anaerobic Bacteria Diversity Index Normal None 0.46 0.60 0.71

Heterotrophic Bacteria Poisson Log 0.96 0.94 0.54

Heterotrophic Bacteria Diversity Index Normal None 0.68 0.74 0.71

Nitrogen-fixing Bacteria Poisson Log 0.72 0.48 0.99

Nitrogen-fixing Bacteria Diversity Index Normal None 0.88 0.06 0.71

Pseudomonads Poisson Log 0.59 0.49 0.69 Pseudomonads Diversity Index Normal None 0.44 0.04 0.08 Total Species Richness Index Gamma None 0.67 0.20 0.24 Yeast/Mold Normal Log 0.81 0.001 0.03 Yeast/Mold Diversity Index Normal None 0.84 0.41 0.33

Table 7. Size of flooded fields fields (ha) on three farms during the pre-treatment period. Treatment Period Hedlin Mesman Thulen Flooded - Fall 2007 6.9 4.4 1.9 Flooded - Winter 2007 6.9 5.4 2.6 Flooded - Spring 2008 6.9 5.4 2.5 Flooded - Fall 2008 6.2 4.4 2.3 Flooded - Winter 2008 7.2 5.4 2.5 Flooded - Spring 2009 6.9 5.3 1.7

29

FIGURES

Thulen Farm

Hedlin Farm

Mesman Farm

Figure 1. Map of the three privately-owned farms on the Skagit River delta, WA, participating in the study.

30

Figure 2. Map of farming practice treatments on the Hedlin and Mesman farm (left) and the Thulen farm (right).

31

0.00

0.20

0.40

0.60

0.80

Winter2006

Spring2007

Fall 2007

Winter2007

Spring2008

Fall 2008

Winter2008

Spring2009

Sampling period

Mea

n no

n-cr

op s

peci

esfre

quen

cy o

f occ

uren

ceFloodedForage HarvestGrazed

Figure 3. Mean non-crop species frequency of occurrence (95% CI) on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods.

32

Figure 4. Reed canarygrass frequency of occurrence (95% CI) on flooded, forage harvest, and grazed treatments of three privately owned farms on the Skagit River delta sampled from Winter 2006 to Spring 2009. Treatments were applied between the Spring 2007 and Fall 2007 sampling periods.

33

0.00

0.20

0.40

0.60

0.80

1.00

1.20

Winter2006

Spring2007

Fall 2007

Winter2007

Spring2008

Fall 2008

Winter2008

Spring2009

Sampling Period

Mea

n cr

op s

peci

esfre

quen

cy o

f occ

uren

ceFloodedForage HarvestGrazed

Figure 5. Mean crop species frequency of occurrence (95% CI) on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta. Treatments were applied between the Spring 2007 and Fall 2007 sampling periods.

34

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

Winter2006

Spring2007

Fall 2007

Winter2007

Spring2008

Fall 2008

Winter2008

Spring2009

Sampling period

Mea

n w

etla

nd s

peci

esfre

quen

cy o

f occ

uren

ceFloodedForage HarvestGrazed

Figure 6. Mean wetland species frequency of occurrence (95% CI) on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately-owned farms on the Skagit River delta. Treatments were applied between the Spring 2007 and Fall 2007 sampling periods.

35

4.0

5.0

6.0

7.0

8.0

9.0

Winter2006

Spring2007

Fall2007

Winter2007

Spring2008

Fall2008

Winter2008

Spring2009

Sampling period

Mea

n pH

FloodedForage HarvestGrazed

Treatment

Figure 7. Mean pH (95% CI) found on transects on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods.

36

1.0

10.0

100.0

1000.0

Winter2006

Spring2007

Fall2007

Winter2007

Spring2008

Fall2008

Winter2008

Spring2009

Sampling period

Mea

n S

um n

itrog

en (l

bs/a

cre)

FloodedForage HarvestGrazed

Treatment

Figure 8. Mean sum nitrogen (95% CI) found on transects on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic.

37

0.1

1.0

10.0

100.0

1000.0

10000.0

Winter2006

Spring2007

Fall2007

Winter2007

Spring2008

Fall2008

Winter2008

Spring2009

Sampling Period

Mea

n am

mon

ium

(lbs

/acr

e)

FloodedForage HarvestGrazed

Treatment

Figure 9. Mean ammonium (95% CI) found on transects on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic. 38

0.0

0.1

1.0

10.0

100.0

1000.0

Winter2006

Spring2007

Fall2007

Winter2007

Spring2008

Fall2008

Winter2008

Spring2009

Sampling period

Mea

n ni

trate

(lbs

/acr

e)FloodedForage HarvestGrazed

Treatment

Figure 10. Mean nitrate (95% CI) found on transects on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic.

39

0.1

1.0

10.0

100.0

Winter2006

Spring2007

Fall2007

Winter2007

Spring2008

Fall2008

Winter2008

Spring2009

Sampling period

Mea

n bo

ron

(mg/

kg)

FloodedForage HarvestGrazed

Treatment

Figure 11. Mean boron (95% CI) found on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic.

40

10.0

100.0

1000.0

10000.0

Winter2006

Spring2007

Fall2007

Winter2007

Spring2008

Fall2008

Winter2008

Spring2009

Sampling period

Mea

n Iro

n (m

g/kg

)FloodedForage HarvestGrazed

Treatment

Figure 12. Mean iron (95% CI) found on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. The scale of the Y-axis on the top graph is logarithmic.

41

0.0

0.1

1.0

10.0

100.0

1000.0

10000.0

Winter2006

Spring2007

Fall2007

Winter2007

Spring2008

Fall2008

Winter2008

Spring2009

Sampling period

Man

gane

se (m

g/kg

)FloodedForage HarvestGrazed

Treatment

Figure 13. Mean manganese (95% CI) found on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. Red index line indicates the level where manganese is considered high by Soil test Labs.

42

Figure 14. Mean yeast and mold (log transformed; 95% CI) found on flooded, forage harvest, and grazed treatments sampled from Winter 2006 to Spring 2009 on three privately owned farms on the Skagit River delta (top) and on individual farms (bottom). Treatments were applied between the Spring 2007 and Fall 2007 sampling periods. CFU/gdw = Colony forming units/gram dry weight sample.

43

Figure 15. Map of flooded plots on the flooded treatment field on the Thulen farm (top left), Hedlin farm (bottom left), and Mesman farm (bottom right).

44

Figure 16. Total area of flooded treatment field and the area of flooded habitat in the 0-15cm and >15 cm water depths on three farms in the Skagit River delta.

45

46

APPENDIX A. Tables of soil properties values for each sampling period by farm and treatment.

Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 6.00 10.00 6.00 3.00 3.00 3.00Boron 0.80 1.00 0.60 0.80 1.10 0.80Base Saturation 64.70 56.90 47.70 79.40 94.80 72.50Buffer Ph 7.00 6.90 6.80 7.00 7.10 6.90Calcium 11.40 12.00 8.90 9.80 11.70 8.10CEC 21.70 26.10 23.50 15.60 15.70 14.30Copper 6.40 6.00 6.70 4.90 5.10 5.60Electrical Conductivity 0.88 0.86 0.48 2.03 2.46 1.14Est_EC 2.29 2.24 1.25 5.28 6.40 2.96Iron 182.00 168.00 209.00 152.00 131.00 166.00P 242.00

1.40M 1.50S 0.30N 16.00O 4.40P 9.00

6.00S 255.00S 19.00T 10.40Z 0.70A 7.00E+06

1.00A 2.70E+06A 0.90H 1.20E+08H 2.00N 8.00E+04N 0.60P 20.00P 1.20E+06P 2.30T 8.20Y 8.80E+04

1.40

HEDLIN HEDLINSPRING 2006 FALL 2006

otassium 203.00 247.00 208.00 198.00 266.00Magnesium 1.80 1.70 1.50 1.50 1.70

anganese 2.40 2.30 2.60 2.00 1.40odium 0.40 0.50 0.30 0.50 0.80itrate 16.00 13.00 13.00 13.00 10.00rganic Matter 3.40 3.70 3.90 4.40 4.40hosphorous 14.00 17.00 10.00 10.00 16.00

pH 6.50 6.30 6.10 6.10 6.30ulfate 287.00 252.00 114.00 596.00 607.00um N 22.00 23.00 19.00 16.00 13.00otal Bases 14.00 14.80 11.20 12.40 14.90inc 1.00 1.20 1.00 0.70 0.80ctinomycetes 6.10E+05 5.00E+05 2.60E+04 6.50E+06 5.10E+06

Actinomycetes Diversity 1.00 0.70 0.00 1.30 0.70naerobic Bacteria 1.80E+07 1.80E+07 1.70E+07 3.10E+06 7.30E+06naerobic Bacteria Diversity 0.60 0.70 0.80 1.40 0.90eterotrophic Bacteria 2.30E+08 2.00E+08 1.60E+08 1.30E+08 3.80E+08eterotrophic Diversity 1.40 2.00 2.00 1.70 2.00itrogen Bacteria 1.40E+04 3.10E+04 1.20E+04 1.40E+05 2.10E+05itrogen Bacteria Diversity 0.70 0.90 0.50 1.00 0.20ercent moisture 30.00 32.00 31.00 18.00 21.00seudomonads 4.40E+05 1.10E+06 4.10E+05 8.80E+05 4.80E+06seudomonads Diversity 2.30 1.30 2.10 1.70 1.30otal species richness 8.00 7.30 6.40 8.70 7.00east Mold 8.50E+04 6.00E+04 7.50E+04 1.00E+05 5.50E+04

Yeast Diversity 2.00 1.70 1.00 1.60 1.90

Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 19.00 16.00 13.00 6.00 6.00 10.00 3.00 6.00 3.00Boron 1.17 1.07 1.28 1.47 1.55 1.79 0.97 0.87 1.39Base Saturation 85.80 77.80 73.30 54.10 63.00 63.40 60.90 50.90 43.50Buffer Ph 7.10 6.90 6.90 5.90 6.20 6.30 6.80 6.30 6.10Calcium 9.80 10.60 9.10 12.30 12.20 14.30 8.60 7.00 8.30CEC 14.00 16.80 15.60 27.00 24.40 29.80 18.10 17.50 22.00Copper 3.80 3.80 3.80 3.80 3.80 3.80 3.80 3.80 3.80Electrical Conductivity 0.90 0.63 0.56 0.29 0.32 0.39 0.25 0.11 0.13Est_EC 2.34 1.64 1.46 0.75 0.83 1.01 0.65 0.29 0.34Iron 236.00 212.00 275.00 371.00 366.00 397.00 202.00 197.00 332.00Potassium 198.00 233.00 237.00 202.00 261.00 394.00 202.00 191.00 167.00Magnesium 1.40 1.50 1.50 1.50 2.20 2.90 1.70 1.30 0.80Manganese 53.10 25.10 19.60 2.50 2.80 7.50 2.40 2.00 5.20Sodium 0.30 0.40 0.30 0.20 0.30 0.70 0.20 0.10 0.10Nitrate 3.00 10.00 13.00 13.00 22.00 16.00 22.00 13.00 13.00Organic Matter 3.60 4.40 4.80 8.80 8.00 9.60 3.60 4.80 6.80Phosphorous 15.00 13.00 10.00 15.00 14.00 15.00 17.00 20.00 18.00pH 6.50 6.40 6.20 5.60 5.90 6.00 6.00 5.80 5.70Sulfate 277.17 239.00 168.06 76.23 67.54 168.68 38.03 20.87 47.25Sum N 22.00 26.00 26.00 19.00 28.00 26.00 25.00 19.00 16.00Total Bases 12.00 13.10 11.40 14.60 15.40 18.90 11.00 8.90 9.60Zinc 0.80 0.90 0.90 2.30 3.70 3.60 1.20 0.90 1.20Actinomycetes 1.00E+07 7.40E+06 5.10E+06 1.60E+07 1.50E+07 1.40E+07 3.70E+06 1.40E+06 4.90E+06Actinomycetes Diversity 0.90 0.70 0.90 1.00 0.70 0.70 0.90 1.00 0.60Anaerobic Bacteria 3.40E+07 1.40E+07 3.70E+06 1.40E+07 3.80E+06 1.20E+07 9.70E+06 5.80E+06 2.70E+06Anaerobic Bacteria Diversity 0.90 1.10 1.10 0.40 0.90 1.10 1.00 0.60 1.10Heterotrophic Bacteria 1.00E+08 1.50E+08 1.60E+07 9.50E+07 8.40E+07 1.50E+08 5.40E+07 3.90E+07 2.20E+08Heterotrophic Diversity 1.60 1.70 1.20 1.60 1.40 1.20 0.90 1.10 0.70Nitrogen Bacteria 1.30E+04 7.70E+03 0.00E+00 9.90E+03 7.00E+03 3.80E+03 4.00E+03 2.30E+03 0.00E+00Nitrogen Bacteria Diversity 0.20 0.30 -0.30 0.00 0.50 0.00 0.00 0.00 -0.30Percent moisture 33.00 39.00 38.00 47.00 45.00 50.00 29.00 34.00 40.00Pseudomonads 8.90E+05 9.90E+05 2.00E+05 3.90E+05 3.10E+05 6.90E+05 2.80E+05 1.80E+05 2.70E+05Pseudomonads Diversity 1.30 1.70 1.50 1.80 1.50 1.50 1.70 1.30 1.80Total species richness 6.50 7.10 6.20 6.10 5.90 5.80 6.40 5.40 5.20Yeast Mold 9.60E+04 1.30E+05 1.30E+05 2.40E+05 2.60E+05 2.00E+05 5.20E+05 9.80E+04 1.90E+05Yeast Diversity 1.60 1.60 1.80 1.30 0.90 1.30 1.90 1.40 1.30

HEDLIN MESMAN THULENWinter 2006

47

Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 6.00 8.00 6.00 5.00 16.00 11.00 4.00 4.00 5.00Boron 1.24 1.11 0.79 1.71 1.23 1.48 0.84 0.96 1.04Base Saturation 85.10 95.70 84.70 58.60 66.80 77.60 66.20 51.70 51.80Buffer Ph 6.90 6.90 6.70 6.20 6.40 6.50 6.70 6.40 6.50Calcium 8.20 11.20 8.00 11.00 11.90 12.70 7.70 6.80 8.60CEC 12.30 14.70 12.30 22.50 23.00 22.70 15.40 17.10 20.30Copper 6.90 5.90 4.70 5.70 4.40 5.10 3.90 4.40 5.30Electrical Conductivity 0.75 0.78 0.50 0.35 0.60 1.73 0.24 0.13 0.23Est_EC 1.95 2.03 1.30 0.91 1.56 4.50 0.62 0.34 0.60Iron 254.00 216.00 172.00 408.00 285.00 312.00 174.00 206.00 234.00Potassium 198.00 240.00 248.00 162.00 295.00 328.00 200.00 188.00 174.00Magnesium 1.40 1.70 1.50 1.50 2.10 2.80 1.70 1.40 1.20Manganese 3.60 2.40 2.20 2.50 2.00 2.40 1.30 2.40 2.20Sodium 0.38 0.54 0.32 0.28 0.61 1.27 0.34 0.16 0.21Nitrate 19.00 15.00 10.00 4.00 5.00 2.00 9.00 3.00 6.00Organic Matter 3.80 5.40 4.20 7.00 9.20 9.60 3.60 4.40 5.20Phosphorous 11.00 12.00 7.00 9.00 9.00 10.00 14.00 17.00 12.00pH 5.90 6.10 5.90 5.50 5.70 5.60 5.90 5.70 5.60Sulfate 204.00 281.00 127.00 91.00 57.00 250.00 32.00 18.00 45.00Sum N 25.00 23.00 16.00 9.00 21.00 13.00 13.00 7.00 11.00Total Bases 10.50 14.10 10.40 13.20 15.40 17.60 10.20 8.80 10.50Zinc 1.00 0.90 0.60 3.10 3.20 3.00 0.90 1.10 0.90Actinomycetes 5.00E+06 4.10E+06 3.50E+06 8.40E+06 3.30E+05 1.90E+07 3.10E+06 3.80E+06 5.60E+06Actinomycetes Diversity 1.30 1.10 0.90 0.70 0.90 0.50 0.30 0.80 0.90Anaerobic Bacteria 6.00E+06 2.20E+07 4.60E+06 8.00E+06 3.90E+06 2.50E+07 4.90E+06 2.30E+07 1.30E+07Anaerobic Bacteria Diversity 0.60 0.70 0.80 0.70 1.20 0.70 1.00 0.50 0.60Heterotrophic Bacteria 5.50E+07 9.70E+07 9.00E+07 8.60E+07 1.00E+08 1.60E+08 8.00E+07 3.40E+08 5.60E+07Heterotrophic Diversity 1.70 1.40 1.60 1.90 1.10 1.70 1.60 0.50 1.70Nitrogen Bacteria 1.80E+04 2.70E+03 3.10E+04 3.20E+03 1.30E+04 1.80E+04 3.70E+03 6.40E+03 3.10E+04Nitrogen Bacteria Diversity 0.50 0.30 0.70 0.30 0.70 0.20 0.00 0.30 0.90Percent moisture 28.00 29.00 27.00 40.00 39.00 41.00 23.00 24.00 27.00Pseudomonads 4.40E+05 5.20E+05 7.90E+05 9.90E+05 4.20E+06 1.30E+06 3.00E+05 1.20E+06 8.10E+05Pseudomonads Diversity 1.60 2.10 1.50 2.20 1.70 1.80 1.30 1.50 0.80Total species richness 7.10 7.20 6.80 6.90 7.40 6.00 5.80 4.50 6.50Yeast Mold 8.30E+04 8.20E+04 2.90E+05 1.80E+05 4.60E+05 4.60E+05 2.90E+05 2.40E+05 3.20E+05Yeast Diversity 1.40 1.60 1.30 1.10 1.80 1.10 1.60 0.90 1.60

HEDLIN MESMAN THULENSPRING 2007

48

Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 43.00 4.00 2.00 26.00 3.00 24.00 28.00 6.00 4.00Boron 1.31 0.61 0.57 3.06 1.05 0.96 0.98 0.63 0.68Base Saturation 47.20 64.90 50.70 44.20 46.20 59.10 83.10 47.60 42.10Buffer Ph 7.10 7.00 7.00 6.70 6.40 6.60 6.80 6.70 6.60Calcium 7.00 8.50 6.50 7.40 10.20 11.20 5.70 6.60 8.50CEC 18.40 18.00 17.00 24.10 28.90 25.30 19.40 20.20 23.60Copper 2.80 3.50 3.60 1.10 3.60 3.40 3.20 2.70 3.60Electrical Conductivity 0.28 1.32 0.79 1.18 0.82 1.38 5.19 0.74 0.23Est_EC 0.73 3.43 2.05 3.07 2.13 3.59 13.49 1.92 0.60Iron 327.00 113.00 125.00 781.00 253.00 210.00 203.00 147.00 164.00Potassium 154.00 191.00 172.00 196.00 215.00 286.00 222.00 166.00 144.00Magnesium 1.10 1.80 1.40 1.50 1.90 2.20 2.80 1.70 0.90Manganese 79.50 1.80 1.20 9.10 1.40 1.10 36.70 6.70 1.10Sodium 0.19 0.90 0.34 1.22 0.67 0.88 7.03 0.89 0.13Nitrate 3.00 12.00 12.00 2.00 10.00 20.00 3.00 4.00 11.00Organic Matter 3.00 3.60 3.20 5.40 6.20 8.00 3.40 3.40 4.40Phosphorous 12.00 9.00 4.00 14.00 6.00 7.00 8.00 10.00 10.00pH 6.60 6.10 5.90 5.40 5.50 5.60 5.60 5.50 5.90Sulfate 61.00 250.00 169.00 187.00 153.00 293.00 169.00 38.00 47.00Sum N 46.00 16.00 14.00 28.00 13.00 44.00 31.00 10.00 15.00Total Bases 8.70 11.70 8.60 10.70 13.40 14.90 16.10 9.60 9.90Zinc 0.50 0.50 0.40 1.10 2.70 1.90 0.90 0.70 0.60Actinomycetes 6.10E+06 6.20E+06 3.80E+06 9.60E+06 1.40E+07 1.80E+07 8.50E+06 2.60E+06 5.90E+06Actinomycetes Diversity 1.00 0.90 0.80 0.70 0.80 0.80 0.90 0.90 0.70Anaerobic Bacteria 4.00E+07 3.60E+07 8.70E+06 6.40E+07 1.50E+07 2.80E+07 1.60E+07 1.80E+07 1.10E+07Anaerobic Bacteria Diversity 0.70 0.50 0.60 0.50 1.00 0.70 0.80 0.70 1.00Heterotrophic Bacteria 5.80E+07 3.30E+08 9.70E+07 9.00E+07 7.50E+07 1.90E+08 3.40E+07 9.70E+07 6.70E+07Heterotrophic Diversity 1.90 1.60 1.50 2.30 2.30 2.20 1.70 1.90 2.60Nitrogen Bacteria 3.10E+05 8.20E+05 1.20E+06 5.50E+05 7.40E+04 2.60E+05 1.10E+05 5.30E+05 3.10E+05Nitrogen Bacteria Diversity 0.40 0.70 0.70 0.50 0.40 0.60 0.40 0.30 0.20Percent moisture 37.00 32.00 34.00 56.00 37.00 42.00 40.00 30.00 35.00Pseudomonads 1.40E+07 5.40E+07 2.60E+07 1.30E+07 1.00E+07 4.00E+07 6.40E+06 3.00E+07 1.80E+07Pseudomonads Diversity 1.50 1.40 1.50 1.50 1.60 2.00 1.00 2.50 1.70Total species richness 6.50 6.70 6.50 6.70 7.80 8.30 5.20 8.30 7.70Yeast Mold 6.90E+04 1.40E+05 1.20E+05 4.90E+05 6.30E+05 7.30E+05 2.00E+05 3.20E+05 3.10E+05Yeast Diversity 1.00 1.60 1.40 1.20 1.70 2.00 0.40 2.00 1.50

HEDLIN MESMAN THULENFALL 2007

49

Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 45.00 18.00 71.00 79.00 20.00 20.00 16.00 11.00 22.00Boron 1.10 1.18 1.15 3.55 2.26 1.95 1.42 1.17 1.60Base Saturation 56.60 65.30 57.60 45.80 55.70 59.00 85.10 41.60 41.30Buffer Ph 6.90 6.80 6.70 5.90 6.00 6.10 6.30 6.10 6.10Calcium 7.30 9.90 8.10 10.90 12.70 13.90 4.70 7.30 8.40CEC 15.80 19.00 18.10 30.50 28.40 31.50 14.10 23.00 24.30Copper 4.40 6.40 6.80 5.10 7.80 6.10 6.30 5.50 8.10Electrical Conductivity 0.33 0.76 0.45 0.75 0.36 0.69 1.26 0.25 0.32Est_EC 0.86 1.98 1.17 1.95 0.94 1.79 3.28 0.65 0.83Iron 247.00 226.00 240.00 838.00 526.00 415.00 290.00 259.00 364.00Potassium 151.00 201.00 223.00 248.00 230.00 320.00 205.00 167.00 190.00Magnesium 1.10 1.40 1.50 1.60 2.00 2.80 2.90 1.40 0.90Manganese 65.40 6.30 23.60 10.20 10.30 12.10 30.80 5.10 8.90Sodium 0.19 0.56 0.30 0.93 0.50 1.12 3.83 0.48 0.21Nitrate 1.00 14.00 10.00 1.00 6.00 6.00 1.00 4.00 10.00Organic Matter 4.00 4.40 4.80 8.80 8.80 10.00 5.20 5.60 6.00Phosphorous 15.00 12.00 10.00 24.00 15.00 15.00 18.00 19.00 18.00pH 6.50 6.20 6.20 5.40 5.80 5.90 5.60 5.50 5.60Sulfate 55.00 222.00 70.00 191.00 103.00 137.00 113.00 38.00 60.00Sum N 46.00 32.00 81.00 80.00 26.00 26.00 17.00 15.00 32.00Total Bases 8.90 12.40 10.40 14.00 15.80 18.60 12.00 9.60 10.00Zinc 0.60 1.00 1.00 2.10 4.60 3.50 1.70 1.20 1.10Actinomycetes 6.60E+06 3.00E+06 6.40E+06 1.60E+07 1.30E+07 1.90E+07 7.20E+06 3.90E+06 6.80E+06Actinomycetes Diversity 1.30 1.20 1.30 0.60 0.40 1.00 1.00 0.80 0.70Anaerobic Bacteria 1.80E+06 2.00E+06 3.90E+06 3.60E+06 1.30E+07 9.40E+06 9.50E+06 3.10E+06 3.90E+07Anaerobic Bacteria Diversity 0.50 0.60 0.90 0.60 1.10 0.40 1.00 0.60 0.40Heterotrophic Bacteria 3.90E+07 4.80E+07 2.80E+07 6.60E+07 8.80E+07 1.20E+08 6.20E+07 3.50E+07 6.60E+07Heterotrophic Diversity 1.80 2.60 1.70 1.90 2.80 1.00 2.20 1.70 1.50Nitrogen Bacteria 3.90E+05 1.60E+05 1.40E+05 7.10E+04 5.10E+05 3.20E+05 3.60E+05 3.50E+05 7.90E+05Nitrogen Bacteria Diversity 0.40 0.80 0.80 0.80 0.20 0.50 0.50 0.20 0.50Percent moisture 39.00 35.00 36.00 59.00 55.00 57.00 48.00 37.00 42.00Pseudomonads 1.30E+07 1.00E+07 1.10E+07 1.30E+07 1.30E+07 1.40E+07 1.10E+07 1.30E+07 2.40E+07Pseudomonads Diversity 2.10 2.10 4.10 1.70 1.50 2.10 1.80 2.50 1.90Total species richness 7.50 8.60 10.10 7.50 7.60 6.70 8.50 7.20 6.40Yeast Mold 7.40E+04 6.00E+04 5.60E+04 1.60E+05 4.90E+05 2.40E+05 4.10E+05 5.00E+05 3.80E+05Yeast Diversity 1.40 1.30 1.30 1.90 1.60 1.70 2.00 1.40 1.40

WINTER 2007HEDLIN MESMAN THULEN

50

Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 21.00 14.00 8.00 174.00 26.00 15.00 15.00 12.00 11.00Boron 1.98 2.23 1.71 5.13 3.59 4.08 1.27 2.07 1.38Base Saturation 62.20 56.80 55.00 37.60 46.90 58.80 40.90 37.90 44.40Buffer Ph 7.00 6.90 7.00 6.60 6.50 6.50 6.70 6.40 6.50Calcium 8.50 8.70 7.70 7.20 9.80 13.50 4.00 6.50 7.30CEC 16.40 19.30 17.40 25.80 27.40 31.40 23.20 22.20 22.30Copper 5.60 8.60 7.50 1.90 6.40 8.70 3.80 7.10 5.50Electrical Conductivity 0.10 0.53 0.30 0.39 0.29 0.84 0.72 0.22 0.35Est_EC 0.26 1.38 0.78 1.01 0.75 2.18 1.87 0.57 0.91Iron 366.00 368.00 294.00 945.00 679.00 713.00 220.00 375.00 243.00Potassium 204.00 221.00 197.00 268.00 258.00 303.00 199.00 148.00 195.00Magnesium 1.00 1.30 1.10 1.30 1.90 3.00 2.80 1.10 1.40Manganese 140.80 14.80 29.10 5.50 21.90 21.70 18.50 5.90 7.60Sodium 0.15 0.45 0.24 0.55 0.46 1.23 2.27 0.35 0.71Nitrate 2.00 16.00 11.00 1.00 2.00 3.00 2.00 2.00 9.00Organic Matter 4.00 4.80 4.00 8.00 8.40 10.00 5.20 5.20 5.60Phosphorous 14.00 9.00 7.00 12.00 7.00 10.00 8.00 17.00 11.00pH 7.10 6.20 6.50 5.90 5.90 6.00 6.00 5.60 5.80Sulfate 18.00 155.00 76.00 135.00 112.00 236.00 64.00 45.00 45.00Sum N 23.00 30.00 19.00 175.00 28.00 18.00 17.00 14.00 20.00Total Bases 10.20 11.00 9.60 9.70 12.90 18.50 9.50 8.40 9.90Zinc 0.80 1.40 1.00 1.30 4.50 4.40 1.00 1.30 1.00Actinomycetes 3.00E+06 3.50E+06 3.80E+06 4.30E+06 7.10E+06 2.90E+06 2.30E+06 0.00E+00 3.00E+06Actinomycetes Diversity 0.60 0.90 0.90 0.50 0.70 0.50 0.60 -0.30 0.80Anaerobic Bacteria 4.20E+07 2.80E+07 4.10E+07 4.80E+07 1.00E+07 2.30E+07 1.70E+07 2.80E+07 5.00E+07Anaerobic Bacteria Diversity 0.70 0.70 0.50 0.50 0.90 1.00 0.70 0.30 0.50Heterotrophic Bacteria 4.90E+08 4.10E+08 4.90E+08 1.70E+08 1.40E+08 2.00E+08 3.80E+08 7.20E+07 1.20E+08Heterotrophic Diversity 1.50 1.60 1.40 1.70 1.30 1.80 1.40 1.50 1.70Nitrogen Bacteria 4.40E+04 6.90E+04 5.20E+05 0.00E+00 5.30E+05 1.90E+05 4.70E+04 3.30E+04 3.30E+05Nitrogen Bacteria Diversity 0.90 1.00 0.30 -0.30 0.30 0.20 1.10 0.20 0.70Percent moisture 41.00 45.00 36.00 65.00 52.00 55.00 44.00 33.00 35.00Pseudomonads 3.60E+05 3.50E+06 5.20E+06 4.80E+05 4.70E+06 1.10E+06 2.40E+05 6.20E+06 1.80E+07Pseudomonads Diversity 1.30 1.50 1.20 0.90 1.30 1.30 1.10 1.20 1.10Total species richness 6.40 6.80 6.50 4.90 5.50 6.70 7.10 4.30 5.90Yeast Mold 7.00E+04 4.50E+04 8.20E+04 1.10E+05 1.60E+05 2.10E+05 1.10E+05 1.00E+05 2.40E+05Yeast Diversity 1.40 1.10 2.20 1.60 1.00 1.90 2.20 1.40 1.10

THULENHEDLIN MESMANSPRING 2008

51

Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 102.00 12.00 21.00 178.00 12.00 20.00 46.00 12.00 51.00Boron 2.12 1.37 1.62 3.92 2.26 1.94 1.65 1.30 1.59Base Saturation 74.05 81.60 71.60 58.20 61.60 72.80 92.75 59.00 59.00Buffer Ph 6.50 6.40 6.30 5.90 5.80 6.00 6.25 6.00 6.00Calcium 7.90 8.30 7.10 9.10 12.20 13.50 4.95 7.10 8.40CEC 13.25 14.10 13.50 21.80 26.20 25.20 14.70 16.00 17.80Copper 6.85 7.10 7.90 7.30 7.60 5.80 5.70 4.90 6.70Electrical Conductivity 0.28 1.60 0.64 0.78 1.24 1.69 2.46 0.27 0.51Est_EC 0.73 4.16 1.66 2.03 3.22 4.39 6.40 0.70 1.33Iron 384.00 239.00 319.00 381.00 383.00 384.00 311.00 260.00 317.00Potassium 212.00 267.00 259.00 330.00 325.00 386.00 297.50 234.00 307.00Magnesium 1.20 1.70 1.60 1.80 2.50 2.90 4.70 1.40 1.10Manganese 37.25 3.70 9.20 16.00 1.80 2.00 25.05 4.10 24.20Sodium 0.17 0.82 0.30 0.95 0.60 0.96 3.03 0.34 0.22Nitrate 1.00 50.00 54.00 1.00 17.00 50.00 21.00 29.00 69.00Organic Matter 3.80 4.00 4.40 7.60 8.80 9.60 4.40 4.80 5.20Phosphorous 7.50 7.00 7.00 11.00 11.00 12.00 9.50 12.00 14.00pH 6.50 5.80 5.90 5.70 5.60 5.80 5.95 5.60 5.80Sulfate 62.00 185.00 106.00 145.00 234.00 201.00 174.50 41.00 74.00Sum N 103.00 62.00 75.00 179.00 29.00 70.00 67.00 41.00 120.00Total Bases 9.80 11.50 9.70 12.70 16.10 18.30 13.45 9.40 10.50Zinc 0.55 1.20 1.00 2.20 4.50 3.00 1.00 0.90 0.90Actinomycetes 4.65E+06 5.90E+06 4.60E+06 4.10E+06 2.40E+06 3.60E+06 3.65E+06 3.50E+06 4.40E+06Actinomycetes Diversity 0.45 0.70 0.80 0.30 0.50 0.60 0.65 0.60 0.80Anaerobic Bacteria 7.60E+07 2.30E+07 5.70E+06 1.50E+07 6.20E+07 9.40E+06 4.59E+07 5.80E+06 5.80E+06Anaerobic Bacteria Diversity 0.55 0.50 1.00 0.70 0.40 0.70 0.70 1.20 0.90Heterotrophic Bacteria 3.00E+08 4.40E+08 2.00E+08 1.70E+08 2.90E+08 5.30E+08 1.28E+08 9.50E+07 1.00E+08Heterotrophic Diversity 1.90 2.10 1.20 2.30 1.30 1.40 1.65 1.50 1.40Nitrogen Bacteria 5.95E+05 2.70E+06 5.40E+05 9.70E+05 2.80E+07 1.10E+07 1.87E+06 1.70E+06 1.50E+06Nitrogen Bacteria Diversity 0.80 0.60 0.50 0.70 0.50 0.40 0.65 0.50 0.50Percent moisture 45.50 30.00 32.00 61.00 38.00 40.00 37.00 27.00 31.00Pseudomonads 3.15E+05 1.10E+07 1.50E+06 1.10E+06 3.20E+07 2.60E+07 1.11E+06 3.60E+06 1.20E+07Pseudomonads Diversity 1.35 1.60 1.60 0.80 0.90 1.20 1.30 1.70 1.70Total species richness 5.85 7.10 6.50 6.00 4.90 5.40 6.20 7.40 6.40Yeast Mold 2.25E+04 1.20E+05 1.30E+05 7.60E+04 1.80E+05 2.60E+05 1.36E+05 1.70E+05 1.80E+05Yeast Diversity 0.80 1.60 1.40 1.20 1.30 1.10 1.25 1.90 1.10

FALL 2008HEDLIN MESMAN THULEN

52

Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 103.00 66.00 45.00 133.00 46.00 114.00 68.00 68.00 76.00Boron 2.62 1.16 0.68 2.62 2.62 2.62 1.82 0.98 1.19Base Saturation 51.10 50.20 42.10 40.40 43.70 62.70 47.20 37.40 38.40Buffer Ph 6.60 6.50 6.50 5.90 6.00 6.00 6.40 6.10 5.90Calcium 7.10 9.30 5.90 9.40 11.50 12.90 4.30 6.20 8.00CEC 17.00 23.60 19.50 30.90 34.90 27.10 21.60 21.90 25.90Copper 6.40 6.80 5.30 4.80 7.70 9.10 6.70 4.90 7.30Electrical Conductivity 0.26 0.88 0.37 0.52 0.61 0.81 0.78 0.16 0.28Est_EC 0.68 2.29 0.96 1.35 1.59 2.11 2.03 0.42 0.73Iron 540.00 252.00 192.00 839.00 532.00 524.00 318.00 248.00 275.00Potassium 222.00 235.00 215.00 332.00 285.00 380.00 281.00 210.00 272.00Magnesium 0.80 1.30 1.40 1.40 2.30 2.30 3.00 1.20 0.90Manganese 118.20 7.50 5.80 16.90 14.40 11.70 36.30 6.90 7.10Sodium 0.21 0.59 0.38 0.86 0.65 0.83 2.16 0.24 0.35Nitrate 7.00 20.00 23.00 5.00 24.00 49.00 5.00 27.00 34.00Organic Matter 4.40 4.20 3.70 8.60 9.00 10.00 3.70 4.10 4.90Phosphorous 15.00 12.00 6.00 18.00 12.00 13.00 13.00 15.00 115.00pH 6.50 6.20 6.00 5.80 5.80 5.90 6.40 5.90 5.80Sulfate 39.00 184.00 51.00 134.00 152.00 220.00 76.00 22.00 47.00Sum N 110.00 86.00 68.00 138.00 70.00 163.00 73.00 95.00 110.00Total Bases 8.70 11.80 8.20 12.50 15.30 17.00 10.20 8.20 9.90Zinc 1.00 0.90 0.60 1.70 3.80 4.50 1.60 1.10 1.00Actinomycetes 3.90E+06 5.40E+06 4.60E+06 6.80E+06 1.30E+07 1.30E+07 4.60E+06 4.40E+06 2.80E+06Actinomycetes Diversity 0.60 0.40 0.80 0.70 0.70 0.70 0.80 0.90 0.80Anaerobic Bacteria 1.90E+06 1.40E+07 1.80E+07 2.40E+07 2.10E+06 4.00E+06 5.80E+06 1.20E+07 1.40E+06Anaerobic Bacteria Diversity 0.50 0.30 0.40 0.80 0.90 0.80 0.30 0.10 1.00Heterotrophic Bacteria 2.60E+07 9.60E+06 1.00E+08 1.20E+07 1.40E+07 2.20E+08 6.40E+07 7.40E+07 8.50E+07Heterotrophic Diversity 2.30 0.70 1.40 1.00 1.30 1.60 1.30 1.40 1.40Nitrogen Bacteria 1.70E+05 2.40E+05 6.20E+05 6.60E+04 3.90E+04 1.20E+05 1.70E+05 2.90E+05 1.30E+05Nitrogen Bacteria Diversity 0.60 0.70 0.70 0.60 0.90 0.60 0.60 0.40 0.60Percent moisture 49.00 36.00 39.00 62.00 51.00 51.00 50.00 41.00 37.00Pseudomonads 3.10E+05 1.10E+06 1.30E+06 8.30E+05 9.80E+05 4.30E+06 1.30E+05 7.00E+05 1.40E+06Pseudomonads Diversity 1.10 1.80 2.60 1.50 1.70 1.40 1.40 1.70 3.30Total species richness 6.20 6.30 8.40 5.70 7.80 7.00 6.10 6.70 8.70Yeast Mold 2.30E+04 9.90E+04 6.70E+04 3.40E+04 2.00E+05 2.20E+05 1.60E+05 8.80E+04 1.20E+05Yeast Diversity 1.10 2.40 2.50 1.10 2.30 1.90 1.70 2.20 1.60

HEDLIN MESMAN THULENWINTER 2008

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Soil Variables Flooded Forage Harvest Grazed Flooded Forage Harvest Grazed Flooded Forage Harvest GrazedAmmonium 60.00 12.00 6.00 107.00 14.00 6.00 35.00 5.00 4.00Boron 2.08 1.03 0.64 3.66 1.87 1.24 1.84 0.44 0.57Base Saturation 48.60 65.90 55.30 47.80 55.20 64.30 60.60 42.10 44.10Buffer Ph 6.80 6.70 6.70 6.00 6.30 6.30 6.60 6.30 6.40Calcium 7.20 9.80 6.40 9.40 11.30 12.90 5.30 6.00 7.90CEC 18.00 18.50 15.60 26.30 26.70 26.40 18.60 18.90 22.10Copper 4.70 5.70 4.70 4.00 5.80 4.70 6.70 2.80 4.10Electrical Conductivity 0.22 0.41 0.39 0.52 0.52 0.38 0.73 0.18 0.16Est_EC 0.57 1.07 1.01 1.35 1.35 0.99 1.90 0.47 0.42Iron 425.00 230.00 171.00 657.00 396.00 283.00 364.00 147.00 169.00Potassium 152.00 199.00 180.00 280.00 200.00 300.00 268.00 137.00 219.00Magnesium 0.90 1.40 1.30 1.50 2.00 2.30 3.10 1.20 0.90Manganese 100.20 4.70 2.30 8.00 6.00 2.90 27.20 2.30 2.40Sodium 0.31 0.45 0.39 0.94 0.91 0.99 2.13 0.41 0.34Nitrate 4.00 38.00 31.00 5.00 35.00 41.00 11.00 16.00 21.00Organic Matter 4.20 4.60 4.20 8.60 9.40 9.80 5.20 5.40 5.40Phosphorous 14.00 12.00 7.00 18.00 9.00 10.00 12.00 13.00 13.00pH 6.50 6.20 6.00 5.40 5.50 5.80 6.10 5.70 5.70Sulfate 25.00 111.00 58.00 192.00 157.00 150.00 120.00 17.00 25.00Sum N 64.00 50.00 37.00 112.00 49.00 47.00 46.00 21.00 25.00Total Bases 8.80 12.20 8.60 12.60 14.80 17.00 11.30 8.00 9.70Zinc 0.90 0.90 0.60 1.60 3.60 2.40 1.30 0.60 0.90Actinomycetes 1.70E+06 5.30E+06 4.20E+06 3.50E+06 4.90E+06 7.10E+06 2.70E+06 1.40E+06 3.50E+06Actinomycetes Diversity 0.60 0.60 0.80 0.80 0.40 0.70 0.30 0.30 0.30Anaerobic Bacteria 2.20E+07 1.00E+07 2.20E+07 2.70E+07 7.40E+06 5.30E+06 6.50E+06 5.20E+06 5.30E+06Anaerobic Bacteria Diversity 0.50 0.70 0.70 0.80 0.60 0.70 1.30 1.00 0.70Heterotrophic Bacteria 1.10E+08 1.50E+08 9.40E+07 1.10E+08 3.20E+08 3.30E+08 8.10E+07 1.00E+08 3.40E+08Heterotrophic Diversity 1.90 1.50 1.60 2.20 1.90 1.80 0.90 1.50 0.50Nitrogen Bacteria 1.40E+05 6.00E+05 5.40E+04 7.20E+04 1.20E+05 6.80E+05 1.80E+05 3.60E+05 1.70E+05Nitrogen Bacteria Diversity 0.60 0.20 0.60 1.00 0.40 0.70 0.40 0.50 0.60Percent moisture 43.00 38.00 41.00 58.00 42.00 43.00 40.00 30.00 32.00Pseudomonads 1.80E+05 1.70E+06 1.70E+06 3.10E+05 2.20E+06 1.80E+06 5.60E+04 3.80E+06 2.00E+05Pseudomonads Diversity 1.50 1.90 1.80 1.30 1.40 1.80 1.10 1.40 1.30Total species richness 5.80 6.70 6.80 7.50 5.40 6.90 5.00 6.00 4.40Yeast Mold 2.70E+04 8.50E+04 2.80E+05 1.20E+05 4.20E+05 1.60E+05 1.10E+05 2.80E+05 1.80E+05Yeast Diversity 0.70 1.80 1.30 1.40 0.70 1.20 1.00 1.30 1.00

SPRING 2009MESMAN THULENHEDLIN

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