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Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside L. Gaston and W. Felicien LSU AgCenter School of Plant, Environmental and Soil Sciences

Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

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Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside L. Gaston and W. Felicien LSU AgCenter School of Plant, Environmental and Soil Sciences. Rationale Marginally productive land used for pasture and timber may be more productive with non-pasture, biomass grasses - PowerPoint PPT Presentation

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Page 1: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Soil and Water Quality with Miscanthus on aLouisiana Coastal Plain Hillside

L. Gaston and W. Felicien

LSU AgCenterSchool of Plant, Environmental and Soil Sciences

Page 2: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Rationale Marginally productive land used for pasture and timber may be more productive with non-pasture, biomass grasses

Good for the landowner / producer and local community Positive direction with respect to energy dependency and climate change Depends on sustainable production without negative environmental effect 

Objectives YieldNutrient dynamicsSoil qualityWater quality

Page 3: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Overview of the Experiment Location, Field Plot Design, Study Components and Methods

Location LSU AgCenter Calhoun Research Station, Calhoun, LA Western Coastal Plain MLRA 133B Ruston-Lucy Association, Hilly – a sandy loam, acidic soil

Specific site had not be used for years  

Page 4: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Field Plot Design Miscanthus giganteus transplanted spring 2009 @ 1 plant m-2

Treatments applied 2010 RCB design 3 replications with blocks perpendicular to slope (high, middle and low) Plots 5 m x 5 m with 2 m border between plots and 5 m buffer between blocks Treatments include 

Inorganic N @ 80 and 160 kg ha-1

N-based poultry litter @ 80 and 160 kg ha-1

No fertilization controlNo miscanthus, no fertilization = native vegetation control

 Harvest fall to winter for biomass productivity and tissue composition 

Page 5: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Runoff Water Quality Sub-plots (3/4 m x 2 m stainless steel, 10 cm walls, 5 cm deep trough with drain)

In all poultry litter, no fertilizer control and native vegetation plots (12 sub-plots) Parameters include volume, TS, DS, SS, COD, DOC, NH4

+, NO3-, TP, DRP and pH

 All runoff > ~ 200 mL analyzed Begun after treatments applied 2010 

Soil Quality Extractable nutrients, OC and FDA hydrolysis Sampling in late winter before re-growth

Page 6: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Results

Yields

Treatment 2010 2011---------- Mg ha-1 -----------

0 N 5.79 a 6.81 a 80 N inorganic 4.49 a 4.99 a160 N inorganic 7.36 a 7.82 a 80 N poultry litter 7.30 a 7.98 a160 N poultry litter 7.81 a 8.69 a

Low yields and no effect of fertilizer rate or source

Page 7: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Nutrient Removal in Harvest

2011

Treatment Ca Mg P K S-------------------- kg ha-1 --------------------

0 N 11.0 2.4 0.7 11.1 2.0 80 N inorganic 10.2 1.0 0.6 9.4 1.8160 N inorganic 12.9 2.0 0.3 16.1 2.6 80 N poultry litter 16.9 1.8 3.0 20.3 3.2160 N poultry litter 9.8 1.8 4.4 18.3 2.5

Negligible depletion of soil nutrients

2010 similar

Page 8: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Soil Quality Parameters

OC

Treatment 2012 2011 2010 2009-------------- % --------------

0 N 0.80 a b c 0.80 a 80 N inorganic 0.67 b c 0.78 a160 N inorganic 0.65 c 0.74 a 80 N poultry litter 0.88 a 0.94 a160 N poultry 0.88 a 0.84 a

Native vegetation 0.83 a b 0.82 a

Average 0.79 0.82 0.78 0.81

Page 9: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

FDA Hydrolysis

Treatment 2012 2011--- micromoles g-1 h-1 ---

0 N 0.17 a 0.13 a 80 N inorganic 0.17 a 0.16 a160 N inorganic 0.16 a 0.12 a 80 N poultry litter 0.16 a 0.14 a160 N poultry 0.12 b 0.13 a

Native vegetation 0.16 a 0.15 a

Page 10: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Runoff Water Quality

2010

Treatment TS DOC NH4+ NO3

- TP DRP---------------------------- kg ha-1 ----------------------------

0 N 32 a b 9 b 0.3 a 0.1 a 0.3 a 0.2 a 80 N poultry litter 42 a b 7 b 0.2 a 0.2 a 0.3 a 0.3 a160 N poultry 25 a b 8 b 0.3 a 0.1 a 0.5 a 0.4 a

Native vegetation 64 a 20 a 0.5 a 0.2 a 0.3 a 0.2 a

2011

0 N 34 a 4 a 0.2 a 0.1 a 0.1 a 0.1 a 80 N poultry litter 13 a 2 a 0.1 a 0.1 a 0.1 a 0.1 a160 N poultry 19 a 5 a 0.2 a 0.1 a 0.3 a 0.3 a

Native vegetation 35 a 11 a 0.2 a 0.5 a 0.1 a 0.1 a

Page 11: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Discussion

Some indication that miscanthus performs better at lower landscape position,or performs worst at higher position

Block 2010 Yield 2011 Yield ------------ Mg ha-1 ------------

High 4.82 a 4.78 bMiddle 7.38 a 9.31 aLow 7.79 a 7.69 a b

Runoff depth follows this trend but differences are not significant

Little runoff from high position at this site is consistent with measured KSAT

KSAT = 12.3 ± 6.0 cm h-1 (single ring method)

Page 12: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Fast topsoil drainage may reduce available water in absence of less permeable subsoil

Yield data are inversely related to depth to Bt

Depth to Bt Horizon (cm)

0 20 40 60 80 100

Yie

ld (

Mg

ha-1

)

0

4

8

12

R2 = 0.74

Negative relationship between miscanthus yield and depth to the Bt horizon. Data exclude plots from which sample to 1 m could not taken due to wetness (lowest block). Three plots from the highest block had no Bt within 1 m. Depth to these in this figure and the regression was taken as 100 cm.

Page 13: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Relative Depths to Bt Horizon within Treatments

0.0 0.4 0.8 1.2 1.6 2.0

Rel

ativ

e Y

ield

s w

ithin

Tre

atm

ents

0.0

0.4

0.8

1.2

1.6

2.0

2.4

R2 = 0.93

Negative relationship between relative yields of miscanthus within treatments and relative depths to Bt within plots of the same treatment –normalized yields and depths to Bt within treatments.

Page 14: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Subsoil fertility may contribute, however, there is no significant relationship between topsoil chemical fertility and yields

Seep areas below lowest block indicates fairly shallow saturation

Further Planned Work

Depth to saturation unknown –install wells to determine behavior

Fertility level at site is low to very low for common pasture grassesRaise baseline fertility and continue

Page 15: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside

Summary

Yields of miscanthus are low, e.g., 7.3 ± 3.5 Mg ha-1 in 2011, third year

Water may be limiting miscanthus and soil heterogeneity obscuringtreatment effects

In contrast, second year (2011) yields of switchgrass at this site were23.5 ± 3.8 Mg ha-1

Miscanthus appears to be neutral in effect on measures of soil and water quality, i.e., the same as diverse, open-land vegetation

Loss of nutrients in runoff is negligible from miscanthus, even wherepoultry litter is applied at ~ 3 and 6 Mg ha-1

Presumably due to low high infiltration and low soil fertility

Page 16: Soil and Water Quality with Miscanthus on a Louisiana Coastal Plain Hillside