The 4-R Nutrient Stewardship is an industry-driven concept of looking at soil nutrient application. The principles of the approach include the right source of essential nutrients; the right application rate; right application time based on dynamics of crop uptake and soil supply, and risk of nutrient loss; and applying in the right place to meet crop needs.
From a farm standpoint, 4-R Nutrient Stewardship considers economics of nutrient use, returns through harvested yield and incorporates practices to keep nutrients on the field for future crop production rather than leaving the field in water runoff, says Greg LaBarge, Ohio State University Extension educator.
The program utilizes a science-based approach to nutrient use in crop production. The program has three main goals:
· Increase crop production and improve profitability;
· Minimize nutrient loss and maintain soil fertility, and
· Ensure sustainable agriculture for generations to come, according to LaBarge.
OSU Extension offers several new online resources to help determine the rate of nutrients needed. These resources can be found at http://agcrops.osu.edu/specialists/fertility/fertility-fact-sheets-and-bulletins .
Two resources can be used to provide phosphorus and potassium recommendations if a producer has a current soil test in-hand. The first is a spreadsheet that will develop recommendations for up to seven fields, with up to a three-crop rotation. In addition to phosphorus and potassium, a lime recommendation can be generated. The beta version of the spreadsheet can be found at http://agcrops.osu.edu/specialists/fertility/-fact-sheets . Producers who prefer to use a paper copy can download a new factsheet entitled, “Developing Phosphorus and Potassium Recommendations for Field Crops (AGF-515-12)” found online at http://ohioline.osu.edu/agf-fact/pdf/ . It walks producers through directions for using printed tables from the publication, “Tri-State Fertilizer Recommendations for Corn, Soybeans, Wheat and Alfalfa E-2567.”
“If looking at soil test reports is new to you or you need a refresher, the factsheet “Interpreting a Soil Test Report (AGF-514-12)” points out key parameters to look at on the report,” LaBarge says. The factsheet is available at http://ohioline.osu.edu/agf-fact/pdf  . The factsheet walks producers through a soil test report, describing desirable ranges and explaining what the numbers mean on a report.
LaBarge emphasizes that a current soil test is the foundation on which a fertility program is developed. “If you do not have a current soil test (taken within the past three years) a good place to start is with a new soil test,” he says. The factsheet, “Soil Sampling to Develop Nutrient Recommendations (AGF 513-12)” is available at http://agcrops.osu.edu/specialists/fertility/fertility-fact-sheets-and-bulletins/Soil_Sampling . This factsheet discusses how to get a representative sample in a field, guidelines for taking a sample and instructions for sending a sample to the lab. Traditional, zone and grid sampling schemes are covered.
A meeting to be held in Wooster, OH, on Feb. 18, will provide information about nutrient management strategies for economical and environmentally beneficial use of manure and fertilizer nutrients in crop production while using the 4-R Nutrient Stewardship approach. See more details about this meeting online at http://agcrops.osu.edu/calendar/nutrient-management-4r-nutrient-stewardship .