IARN — USDA’s Natural Resources Conservation Service (NRCS) is accepting comments on the newly revised Iowa Nutrient Management Standard – the guiding document for implementing nutrient management plans for Iowa farmers.
The (590) Nutrient Management Standard provides farmers guidance on managing the 4Rs of nutrient stewardship: right rate, right source, right place, and right time for applying plant nutrients and soil amendments while reducing environmental impacts. The nutrient management plan includes commercial fertilizer, animal manure, biosolids, composts, legume credits, green manure, and crop rotations. The Standard also includes guidance for management practices and edge of field practices that help minimize offsite nutrient loading.
According to Iowa NRCS State Resource Conservationist Mike Henderson, the Nutrient Management Standard helps both farmers and our natural resources.
“This Standard helps farmers plan nutrients for optimal crop production, fully utilizing manure or organic byproducts as plant nutrient sources,” Henderson said. “It also helps protect water quality by minimizing offsite nutrient loading into our ground and surface waters and fosters soil health by promoting optimal plant growth and facilitating beneficial microbial and nutrient interactions.”
The Iowa 590 Standard is developed from the National 590 Standard, land grant university (Iowa State University) recommendations, and State of Iowa law – which includes Iowa Department of Natural Resources (DNR) regulations concerning manure use and disposal on the land.
The proposed changes are as follows:
The National Standard changes the allowable phosphorus application to maintenance rate when the Phosphorus Index is at a Medium Risk Level. Previously, it was two times maintenance rate.
When using the Nitrogen Rate Calculator (http://cnrc.agron.iastate.edu), a price ratio of 0.08 for commercial fertilizer and 0.05 for manure will be used to set a maximum allowable rate of nitrogen to meet the Standard. Iowa producers will still be encouraged to utilize the Nitrogen Rate Calculator as an economic tool to hone their nitrogen rate. Use of a standard price ratio for the Standard will allow more consistency in applying the Standard across all producers.
For “Sensitive Areas,” the new 590 Standard aligns with State of Iowa law requiring only sensitive areas to be protected when using manure, not commercial nutrients. All 590 Nutrient Management Plans in Iowa will still identify all sensitive areas and address how to protect them.
If using Monoammonium phosphate (MAP) or diammonium phosphate (DAP) in the fall, the nitrogen component can now be given half credit, instead of accounting for all the nitrogen.
The full draft 590 Iowa Nutrient Management Standard is available at https://bit.ly/IAdraftstandards. Email comments to Henderson at Michael.Henderson@usda.gov and CC Kevin Kuhn at kevin.kuhn@usda.gov. Comments will be accepted through April 22.
Story courtesy of the Iowa Agribusiness Radio Network.
Image source: Wikimedia Commons
