USDA-NRCS Announces Updated Nutrient Management Plan

Fertile soil supports vigorous plant growth that covers the soil surface early in the growing season. The increased soil cover will decrease soil moisture evaporation, decrease wind and water erosion, and maximize the amount of plant residue remaining after harvest of the crop to minimize erosion during the offseason. Vigorously growing plants are more resistant to biotic and abiotic stresses, including diseases and insects, weeds, and adverse weather conditions. An effective nutrient management plan identifies the amount, source, time of application, and placement of nutrients needed to sustain economic viability of crops, while simultaneously protecting the environment.

A nutrient management plan is a document that shows how a producer should manage nutrients so that economic benefits are maximized and environmental impacts are minimized. Development of a nutrient management program begins with collecting soil samples from a production unit or field, followed by a soil test.

Sampling protocol to determine nutrient levels in soil at a production site is important to ensure accuracy of test results and proper application of recommended amounts of nutrients to a field or units within a field. Because most fields are variable in topography, slope, and soil series, nutrient levels will vary considerably within a field. Thus, soil samples must be collected in a systematic manner across a uniform field, or within variable units within a field.

Click “Useful Nutrient Management Planning Data” for an MSU-ES publication that provides data and conversion factors that will be helpful in the setup and conduct of a nutrient management plan. Click here for a USDA-NRCS publication titled “Conservation Practice Standard for Nutrient Management” that was published in 2012 and addresses the conservation of soil nutrients for plant production while minimizing nonpoint source pollution that can be attributed to mismanagement in the application and use of soil nutrients.

In a Mar. 2023 news release from NRCS titled “NRCS Refines Nutrient Management Strategies to Improve Conservation Outcomes“, Terry Cosby, Chief of the NRCS, announced that the agency is addressing site-specific risks for nutrient losses from agricultural fields. Included in this refinement is the promotion of NRCS’s SMART Nutrient Management plan, and highlighting the importance of comprehensive, site-specific assessment of nutrient loss risks. Click here for a Sept. 2022 SMART Nutrient Management fact sheet. Pertinent points from the NRCS news release and the SMART Plan follow.

•    Preventing nutrients from fertilizers and other sources from entering local waters will ensure that applied nutrients are used by growing crops. This will subsequently benefit water quality and farmer finances.

•    Soil testing is the key to determining how much of any nutrient to apply to a production site.

•    Proper soil sampling and subsequent analysis of soil samples will tell a producer what nutrients are needed and in what amount based on nutrients already present in the soil and the crop to be grown on the tested site.

•    Farmers are encouraged to adopt practices such as using enhanced efficiency fertilizers and precision application technology when applying fertilizer nutrients to a production site with variable units.

•    NRCS initiated the development of a new mapping tool called the Sensitive Area Analysis Tool that uses soil survey data to help identify field areas that may be more sensitive to nutrient loss.

•    The SMART Plan is based on five components of nutrient stewardship. They are: 1) Right Source that matches crop needs–e.g. delayed or immediate uptake by plants; 2) Right Method of application–e.g. injection into the soil, incorporation into the soil, broadcasting onto the soil surface; 3) Assessment of site-specific conditions so that a nutrient management plan is tailored accordingly, and current management practices such as cover crops and tillage system can be evaluated for their effect on nutrient requirements and losses; 4) Right Rate–e.g. fertilizer nutrients applied according to site-specific conditions and soil test results; and 5) Right Timing–e.g. applying nutrient(s) according to time of crop demand for those nutrient(s).

•    NRCS will establish a new outreach campaign that will highlight the economic benefits of comprehensive nutrient management planning for farmers to ensure that they use nutrient resources effectively and efficiently. Click here for a press release that provides links to USDA-NRCS resources that provide information .about nutrient management planning.

This NRCS initiative will use part of the funds provided to it in the Inflation Reduction Act recently signed into law. These new funds will be used to support climate-smart agriculture, including the above opportunities for nutrient management.

Click NRCS 590 for the agency’s Conservation Practice Standard for Nutrient Management and here to access the Code 590 Field Office Technical Guide for individual states.

Final thoughts about creating a nutrient management plan.

•    A nutrient management plan should 1) be the foundation for providing nutrients for the selected crop, and 2) identify fields that have a high potential for soil erosion and loss of nitrogen and phosphorus [P].

•    Avoid over-application of fertilizer nutrients since they will be subject to loss through soil drainage and/or runoff.

•    The plan should limit the amount of soluble nutrients left in the soil at the end of the crop growing season. This can be done by 1) not over-applying crop fertilizers, and 2) growing a cover crop that will scavenge unused nutrients following a summer crop.

•    The plan should provide a risk assessment of potential nutrient and soil losses by considering field slope, soil hydrologic group, infiltration/ponding potential of soil(s) in the field, the presence of field areas subject to concentrated water flow, and tillage practices. The risk assessment should identify fields or field areas where conservation management practices should be implemented to prevent loss of nutrients from a field.

•    Fields with high soil test P levels should be monitored for P losses via surface water runoff.

•    Erosion risk of a field should be determined by using the Revised Universal Soil Loss Equation, V. 2 [RUSLE2]. Erosion risks are high in fields with soil slopes >4%, fields where intensive tillage is used, and fields where concentrated surface water flow will cause gullies to form.

•    An effective nutrient management plan should identify practices that enhance more efficient nutrient use by plants, and this should subsequently result in a lower environmental impact and improved water quality in the affected watershed.

•    The potential negative impact on the watershed that receives runoff water containing P from agricultural fields increases with soil erosion.

•    Surface applications of P fertilizers will result in increased P leaving the site of application.

•    A field that is addressed by a nutrient management plan should be divided into areas that represent the different crop production potentials within that field. Common factors used for this purpose are soil type/series, past and present production practices, and harvested yield.

•    And finally, soil tests that are used in the development of a nutrient management plan should be conducted according to established/recognized laboratory procedures.

Composed by Larry G. Heatherly, May 2023,