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Relevant Issues and State Specific Regulations for Winter Manure Application

Janina R. W. Kavetsky

ANS 418: Animal Agriculture and the Environment

Michigan State University Fall 2016

December 9, 2016

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Spreading of manure onto winter fields (especially when frozen or snow covered) has

long been a contentious practice in many parts of the United States. Within many states,

agricultural authorities have sought to curb this practice, primarily in hopes of minimizing

associated negative outcomes. Despite this, many established regulations have built in

exceptions, and in states without such rules, winter spreading may be a common practice. The

purpose of this paper is to: analyze negative impacts of this practice, spotlight established bans

and potential outcomes of such bans, highlight how other parts of the country have developed

alternative means to deal with this issue, and finally speculate on possibilities for future control

measures.

Numerous research studies have been conducted that establish a link between winter

manure spreading and negative environmental impacts. According to Randy Pepin in his article,

What’s the Big Deal with Winter Spreading of Manure?, these negative impacts are the result of

nutrients such as nitrogen and phosphorus being introduced into waterways (2013). When excess

phosphorus enters water bodies, it can result in eutrophication (rapid plant growth). When the

excess plants die it causes water hypoxia (low oxygen), which decreases the ability for water

plants and animals to survive (Pepin, 2013). Under normal circumstances, phosphorus will stay

in the ground attached to soil particles. However, in the case of erosion or frozen impervious

ground (where phosphorus remains on soil surface) this nutrient is carried in water runoff (from

snowmelt or precipitation) along with soil into nearest bodies of water. Nitrogen on the other

hand is mainly lost in the atmosphere as ammonia (NH4) in a process known as volatilization.

Nonetheless, many organic manure compounds are both contributors to eutrophication and are

water soluble, meaning they are subject runoff from spring thaw or rain events (Pepin, 2013)

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In a University of Vermont study, researchers found that winter dairy manure application

resulted in runoff concentrations of nitrogen and phosphorus that was 2-15 times greater than

those from summer applications (Meals, 2005). In light of evidence such as this, many feel that

manure spreading should be banned for negative impacts to environment alone. However, this is

only part of the picture; such practices can also have major economic and social implications.

For example- following a 2005 winter in Wisconsin, improperly land applied manure ended up

wiping out 10 years and $2 million worth of restoration works in one watershed, and causing

contamination of private drinking water wells (Meals, 2005).

Looking at things from the farmer’s perspective however, winter spreading is a logical

and necessary practice. Many farms may need to spread in the winter because they have

limitations of storage facilities. Updating storage on farms can be both costly and difficult,

especially if there are nearby residences that could limit placement options for such structures.

Additionally, winter spreading makes sense for farmers as it allows farmer to limit amount of

time devoted to spreading in the spring, which for many farmers is considered one of the busiest

time of the year (Bogovich, 2011).

Despite the inherent complexity of this issue, many states resort to one-size-fits-all

solutions, namely the use of winter manure spreading bans. The oldest of these bans was

established in Vermont in 1995 (Kling, 2013). The state of Vermont bans winter manure

application between December 15 and April 1.Vermont’s ban exists as part of their Accepted

Agricultural Practices (AAPs), and requires farmers to store all manure produced during the

period (107 days) or be able to stack all manure in a way that will not lead to water quality

impacts (discharge). Additionally, the AAPs require the stacking site to be greater than 100 feet

from private wells, property lines, surface water, or land that is subject to annual overflow from

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adjacent waters (Kling, 2013). While all farmers are expected to comply with these regulations,

exemptions may be granted by the secretary of agriculture in emergencies such as failure of

waste storage facilities.

The second oldest state ban was established in Maine in 2001(Kling, 2013). Though less

comprehensive in its requirements, Maine also focuses its spreading prohibition based on time

period (December 1- March 15) (Maine Department of Agriculture). While outright exemptions

do not exist in this state, farmers may apply for ban variances and receive leeway concerning

spreading dates based on the discretion of commission. Variances for this spreading ban are only

granted in case of emergency, and must be made verbally to commissioner or designee followed

by written request within 10 days of verbal request. The variance issued does not entirely let the

farmer off the hook for compliance but, the commission has discretion as to changing the start

date of ban for that specific farmer.

The most recent manure spreading bans were enacted in Pennsylvania (2011) and

Maryland (2013). The ban in Maryland is similar to the ones in Maine and Vermont, where the

ban is centered on spreading prohibition based on calendar dates (November 1 or 15-March 1)

(Kobel, 2016). Like the previous bans the Maryland restriction does have built in exemptions in

case of emergency. The provisions in Pennsylvania on the other hand, base spreading

recommendations on field conditions. Under this regulation spreading is prohibited unless the

field has a 100’ setback from environmentally sensitive areas, if on high slope fields and on

fields without adequate residue or cover crops (Kling, 2013).

When looking over the different states which are employing bans to manage winter

manure spreading, the question one must ask is, what has been the outcome of these regulations?

While the intention of these regulations was to limit the occurrence of discharges, to prove a

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reduction in negative impacts, there is a need for cohesive data pointing to what outcomes were

produced following ban implementation. Wisconsin Discovery Farms conducted one of the first

on-farm evaluation projects to identify the risks of manure application in the late winter period

(Radatz, Cooley and Frame, 2013). Close evaluation of the data indicates that spreading during

early winter (November-January) is much different than spreading in late winter when the frost

extends deeper and is more solid. Further, this project showed that manure applied during

February and March have increased risk of running off and contributing to high nutrient losses

into surface water. Additionally, they found that total bans, increase volume of manure that must

be stored and can increase the risk of runoff during spreading in the spring (Radatz, Cooley and

Frame, 2013).

Based on the findings of the Wisconsin Discovery Farms study, researchers proposed that

a more reasonable approach would be to manage spreading based on field conditions rather than

rigid prohibitions based on calendar dates (Radatz, Cooley and Frame, 2013). Bans based on

calendar date alone do not take into account climactic variations, or individual field

characteristics. For example- there are times when applying early in winter is optimal because

lack of snow and/or frost affords the opportunity for manure to come in contact with the soil.

Along this same line of reasoning, not allowing farmers to begin fieldwork based on calendar

dates can increase risk of runoff or discharge because the window for application is narrower and

potential for runoff from saturated soils and spring rains is greater. Despite this, the study did

illustrate the need for some caution concerning time of year when application occurs. This study

found that around 90% of annual runoff in Wisconsin occurs between December and June. While

runoff between December and March most often occurs from snowmelt or rain on frozen ground,

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simply avoiding application in February and March could reduce total nutrient loss, since 50% of

annual runoff occurs between these two months (Radatz, Cooley and Frame, 2013).

Overall though, because of the complexity of this issue, one-size-fits all legislation often

fails to meet the needs of all those which may be affected by impacts of winter application.

Rather, future legislation would be more effective when employing multiple tactics to minimize

negative spreading impacts. While a strict ban prohibiting spreading starting in November or

December may not be advantageous, because of the increased risk of runoff in February and

March, if a ban must exist, it would be better applied to late winter rather than fall or early

winter. However, a ban alone would likely not be sufficient as it does not address field

conditions or climactic variation in a given season. Therefore a truly comprehensive policy

would have to include standards or means of evaluating field conditions on the day of

application.

Encouragingly enough, not all states resort to bans alone to control winter spreading.

Michigan for example, has chosen to circumvent a ban, and alternatively encouraged farmers to

use an evaluation tool, the Manure Application Risk Index (MARI) to determine if field

conditions are adequate for winter manure spreading. By using this tool before manure

application, farmers are also protected from nuisance complaints under Right to Farm legislation

(ANS 418, 2016). While accordance to MARI recommendations is not mandatory, it allows

farmers protection under Right to Farm should their spreading practices be called into question.

Some states are looking at implementing evaluation tools such as MARI in their own states, but

whether or not they will tie such tools to legislative measures remains to be seen. Despite future

legislative measures however, winter manure spreading is likely to remain a complex and

contentious issue well into the future.

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References

Bogovich, W. (2011. February). Regulations.gov- Comment on Proposed Changes to National

Handbook. Retrieved December 3, 2016 from, https://www.regulations.gov/document?

D=NRCS-2011-0001-0119.

Kling, C. (2013). Iowa State University- State Level Efforts to Regulate Agricultural Sources of

Water Quality Impairment. Retrieved December 3, 2016 ,

http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1026&context=econ_las_pubs.

Kobel, R (2016, July). Bay Journal- Hogan Administration Eyes Relaxing Maryland Farm

Pollution Regulation. Retrieved December 3, 2016 from,

http://www.bayjournal.com/article/hogan_administration_eyes_relaxing_maryland_farm_polluti

on_regulation.

Maine Department of Agriculture, Conservation and Forestry. Nutrient Management Rules.

Retrieved December 3, 2016 from,www.maine.gov/sos/cec/rules/01/001/001c565.doc

Meals, D. (2005, November). CTIC Partners - Research Shows Winter Application of Manure is

a Bad Idea. Retrieved December 03, 2016, from

http://email.ctic.purdue.edu/partners/112005/rnt.asp

Pepin, R. (2013, December). What's the big deal with winter spreading of manure? Retrieved

December 03, 2016, from https://www.extension.umn.edu/agriculture/dairy/manure/whats-the-

big-deal-with-winter-spreading-of-manure/

Radatz, A., E. Cooley, D. Frame (2013, November). UW Discovery Farms- Will Spreading Bans

Reduce Manure Runoff Events? Retrieved December 3. 2016 from,

http://articles.extension.org/pages/67684/will-spreading-bans-reduce-manure-runoff-events.