Nutrients

Fall 1998

By Eric Sideman, Ph.D.
MOFGA’s Director of Technical Services

Very little about farming is natural. In fact, farming is one of the early steps humans took in their drive to conquer nature. Hunting and gathering are the more natural methods that animals employ to procure food for their survival, while farming is a means of procuring enough food with less travel.

As farming methods improved over time, more food could be produced on less land by fewer people, thus supporting a huge population. As a result of modern farming methods that use large scale machinery, chemical fertilizers and chemical methods of pest control and that are typical in developed countries, less than 10% of the population grows food for the rest on fewer farms than ever, and those farms are concentrated in smaller regions of productive land.

Modern farming generally pleases most people because all they have to think about when procuring food is the price the supermarket is charging, and it is cheap. The real costs of modern farming are great, however, but they are hidden. Many people realize the environmental and health costs stemming from tons of toxic chemicals sprayed into the environment to control pests; these chemicals can contaminate soil, air and water. The environment is also impacted as a result of nutrients needed by plants and animals raised on farms, since producing the fertilizer requires a great amount of energy, and then the nutrients are concentrated in small areas.

In a natural community, plant and animal growth is limited by low concentrations of nutrients – phosphorus and nitrogen most commonly – and this limit prevents populations of certain organisms from exploding. I am sure everyone who was of reading age in the ’60s remembers the skyrocketing awareness of phosphates in detergents as TV commercials proclaimed that various companies’ products were low in phosphates.

When nutrients enter an ecosystem, especially such aquatic systems as lakes and bays, populations of algae explode. When the organisms die, they decompose, using up the oxygen that was dissolved in the water. The lake then becomes anaerobic and all of the other organisms die. I remember the tons of dead fish that I saw in the early ’70s on the shore of Lake Erie.

Hunting and gathering have very little environmental impact because they cause very little concentration of nutrients. Likewise, traditional farming methods practiced until the 20th century had minimal impact because farms were small and numerous. Nutrients were rarely concentrated and were never wasted because they were so valuable. Any manure produced on the farm was managed carefully because it was needed for crop production.

Modern farming results in nutrient concentration. Just look at all the grain being delivered to your local livestock farm – train cars full to some poultry operations! When this grain was growing, it accumulated vast amounts of nitrogen and phosphorus from the chemical fertilizer used to grow it. Roughly 75% of these nutrients pass right through the animal and end up in the manure. The larger the livestock operation, the more nutrients will concentrate. Misuse of that manure results in the great environmental impact of modern farming, and this misuse is especially devastating when compounded by misuse of chemical fertilizers on the same farm.

The Need for Regulation

Farmers are an independent lot and hate regulation even more than the average Mainer, but developments in Maine agriculture over the past decades have necessitated regulation. These developments were recognized by the State Conservation District Advisory Council, Manure Management Subcommittee, and include:

• the rapid expansion of dairy herds with a fixed land base;

• the continued practice of spreading manure during the winter when the nutrients are not used by crops and can easily run off or leach into bodies of water and ground water;

• the large amounts of manure being produced on poultry farms where few or no crops are grown and where, consequently, the manure is a waste product rather than a fertilizer and is often disposed of by methods that cost the least in terms of dollars – but usually cost the most in terms of the environment;

• proposals to build large hog production facilities (“factory farms”) in Aroostook County that would have the same manure mismanagement problems as large poultry operations.

Manure should not be considered a waste product. It is a valuable source of nutrients and organic matter needed for crop production. Problems arise only when too much manure is produced in an area that has no need for the nutrients, or when the manure is mismanaged. Both are happening now, but thanks to the Manure Management Subcommittee, L.D. 1874, an Act Regarding Nutrient Management, passed this year, and the Nutrient Management Rules now being developed by the Maine Department of Agriculture will ensure that manure be properly handled.

Nutrient Management Rules

In June, hearings were held around the state for farmers and other interested people to comment on the draft of the Nutrient Management Rule. The Maine Department of Agriculture is working hard to meet the deadline of having a final proposal for Rules back to the Legislature by December 15, 1998. If you would like a copy, call the department. Give your state rep a call and offer your support for good guidelines.

The Draft Rule requires a Nutrient Management Plan (NMP) that shall be written by a certified planner (farmers can get certified themselves) for any farm with more than 50 animal units, any farm that brings in more than 100 tons of manure from off the farm, any farm spreading regulated residuals, and any farm that wants protection under the “Right to Farm Law.” The NMP is a crucial part of proper use of manure. Too many farmers do not account for the nutrients in the manure they spread and insist on adding the “recommended” amount of chemical fertilizer anyway. This results in excess nutrients washing into and polluting bodies of water. The NMP will be developed for the whole farm and will include all nutrients produced on or off the farm. Soil tests and calculations of crop nutrient needs for each field will guide nutrient management, rather than how much manure is in the pile that needs to be spread.

The NMP will identify and establish setbacks for spreading, stacking or storing manure. The distances recommended are 25 feet from any waterway, property line or from the high water mark of any body of water and 100 feet from wells, springs, ponds, lakes and marine waters. The Rule also contains provisions for odor and insect control at storage facilities and spreading sites. Facilities must be large enough to store at least 210 days of manure production in order to prevent overflow in years like this one, when monsoons delay emptying winter stores.

The Rules also require Livestock Operations Permits for certain farms that pose great environmental impact. Included are all farms meeting the EPA definition of a “concentrated animal feeding operation” (a factory farm). Also, any livestock operation that began with or expanded to more than 300 animal units after April 15, 1998, shall obtain a Livestock Operations Permit.

I strongly support the draft rules – in general. My greatest criticism is that the rules do not include any regulations for spreading chemical fertilizers. The impact of the dependence and misuse of these environmentally expensive sources of nutrients should not be ignored.

All farmers need to manage nutrients to be profitable and to protect the environment. If it takes a law, then we need it. Organic guidelines have long recognized the risks associated with misuse of manures and include rules that promote the best management practices, and organic standards prohibit chemical fertilizers. Supporting your local organic farmer is another way to prevent the mismanagement of nutrients.

About the author: Eric is MOFGA’s Director of Technical Services – our “extension agent.” He is available at the MOFGA office to answer questions about farming and gardening.

Categories
Scroll to Top