Nutrient Management Plans
What goes into a Nutirent Management Plan? The Central Coast Regional Water Quality Control Board is asking farmers to develop and implement a nutirent management plan that could be an effective management option to reduce nitrate loads to receiving waters, either surface or ground water. The California Nonpoint Source Pollution Control Program states that development and implementation of such a plan should include the following goals:
- Apply nutrients at rates necessary to achieve realistic crop yields,
- Improve the timing of nutrient application, and
- Use agronomic crop production technology to increase nutrient use efficiency.
The California Nonpoint Source Pollution Control Program states that core components of a nutrient management plan should include:
- Farm and field maps with identified and labeled: acreage and type of crops, soil surveys, location of any environmental sensitive areas including any nearby water bodies and endangered species habitats.
- Realistic yield expectations for the crop(s) to be grown based primarily on the producer’s yield history, State Land Grant University yield expectations for the soil series, or USDA NRCS Soils-5 information for the soil series.
- A summary of the nutrient resources available to the producer, which (at a minimum) include (a) soil test results for pH, phosphorus, nitrogen, and potassium; (b) nutrient analysis of manure, sludge, mortality compost (birds, pigs, etc.), or effluent (if applicable); (c) nitrogen contribution to the soil from legumes grown in rotation (if applicable); and (d) other significant nutrient sources (e.g., irrigation water).
- An evaluation of the field limitations and development of appropriate buffer areas, based on environmental hazards or concerns such as (a) sinkholes, shallow soils over fractured bedrock, and soils with high leaching potential; (b) lands near or draining into surface water; (c) highly erodible soils; and (d) shallow aquifers.
- Use of the limiting nutrient concept to establish a mix of nutrient sources and requirements for the crop based on realistic yield expectations.
- Identification of timing and application methods for nutrients to (a) provide nutrients at rates necessary to achieve realistic yields, (b) reduce losses to the environment, and (c) avoid applications as much as possible to frozen soil and during periods of leaching or runoff.
- Provisions for the proper calibration and operation of nutrient application equipment.
- Provisions to ensure that, when manure from confined animal facilities (excluding CAFOs) is to be used as a soil amendment or is disposed of on land, subsequent irrigation of the land does not leach excess nutrients to surface or ground waters.
- Vegetated Treatment Systems are discussed in Management Measure 6C of the NPS Encyclopedia.
Recent peer-reviewed literature has examined the efficacy and efficiency of agricultural solutions to reducing nitrogen pollution. As reported in Davidson et al. (2012), many existing mitigation strategies for farms have been demonstrated to potentially reduce nitrogen losses within the existing agricultural system by 30 to 50% or more and are currently used as common practices.