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  "What is Nutrient Management?"

The Need for Nutrient Management

Introduction

Contamination of ground and surface water has focused national attention on agricultural production. Nutrients, pesticides, and erosion sediment are all potential contaminants. Animal manure has been blamed for contributing nitrogen and phosphorous to water bodies that are used for recreation and drinking water. Nutrient contamination from animal waste is the focus of this document.

If not utilized productively, animal manure can contaminate public water supplies, groundwater and surface water. Public awareness of animal waste has increased because of health risks and the degradation of water bodies.

More efficient and careful use of animal manure can reduce the discharge of nitrogen and phosphorous to surface and groundwater and improve the efficiency of the farm.

The main focus of this publication is to

  • illustrate why nutrient management plans are needed, and
  • introduce you to nutrient management planning

"Why it is important to control nutrients released from farm?

  • reduce pollution
  • improve efficiency "

 

Limiting Nutrient
What is meant by
"limiting nutrient"?

The phosphorous content of surface water generally is quite low, so usually even a small amount of enrichment from runoff can have a significant fertilizing effect on the receiving water body. The effect usually is increased algae growth in the water or increased growth of aquatic weeds such as cattails. However, if N or some other growth factor is more limiting than P, enrichment of the water with P will not produce a fertilizing effect. This is what is meant by "limiting nutrient" -- the first one that cannot be supplied in sufficient quantities to meet the plant's needs. Its supply thus limits plant growth. Some watersheds in Florida are naturally high in P due to phosphorous deposits and soils naturally rich in P. Nitrogen rather than phosphorouos will be the limiting nutrient in those streams and estuaries.

In many animal agriculture situations, manure is applied to fields at rates that exceed crop phosphorous needs. Phosphorous accumulation in the surface soil increases the amount that will move off site on eroded soil particles. It is also possible with sufficient rate and time to saturate the phosphorous holding capacityof all the soil material above an aquifer, water table or drain. Phosphorous will leach from such P-saturated soil. Then, when the water emerges in springs or sub-surface drainage, aquatic plants may well respond to the P in the water.

The Comprehensive Nutrient Management Plan

The federal government, working with state agencies, is developing policies that affect the discharge of animal waste and nutrients from agricultural operations.These agencies and the policies they develop will have a significant impact on how you operate your farm. The larger operations (defined below) will be required to develop a Comprehensive Nutrient Management Plan (CNMP) that identifies the sources and amounts of nutrients coming into the farm and limits the amounts of these nutrients that leave the farm in surface and groundwater. Smaller operations will need somewhat simpler plans.
"Federal and state
agencies require CNMPs"

Control of excess N and P will be at the heart of the plan. Using manure for crop production and moving manure off farm are two important ways of avoiding environmental problems from nutrients. The nutrient management plan must take into account the characteristics of the watershed area in the vicinity of the farm and its ability to absorb nutrients without a detrimental effect. A sound nutrient management plan also has economic benefits because it helps the farmer efficiently utilize a valuable resource and reduce the amount of commercial fertilizer purchased.
"Control of animal
waste"

Although there are many other issues regarding animal waste, such as odor, pathogens, and mortality disposal, this publication focuses on nitrogen and phosphorous discharged to groundwater and surface water.

Please note that federal, state and local programs are under development and may change after publication of this site. You should monitor these regulations as they evolve. Updates on the policies can be obtained from the agencies by calling or checking their web sites.

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