Agronomists from Ohio State University's College of Food, Agricultural, and Environmental Sciences have created a fact sheet designed to provide growers guidance on soil sampling to develop nutrient recommendations. It enables growers to arrive at a numeric value for the level of phosphorous and potassium available in the field to ensure that they aren't over-applying nutrients and minimizing losses of nutrient at the edge of field affecting water quality, while at the same time not under-applying resulting in less than maximum crop yields.
The fact sheet helps outline the steps needed to better ensure a quality soil sample is achieved, which is key for growers to accurately manage fertility input costs and promote environmental stewardship, says Greg LaBarge, an Ohio State University Extension field specialist and one of the leaders of Ohio State's Agronomic Crops Team.
"The major goal of soil testing is to measure the soil's ability to provide what levels of the vital nutrients phosphorous and potassium are needed for crop production," LaBarge says. "Growers use fertilizer applications to make up the difference for what nutrients aren't already present in the soil for what is needed for crop production."
One way to measure that is through soil testing, where a small volume of soil is used to determine recommendations for a larger field area.
Taking a quality soil sampling that best represents the field area being sampled is key to having a repeatable result, LaBarge says.
"It gives us confidence that our sample best represents what is in the field so that growers aren't left short on nutrients," LaBarge says. "Accurate soil sampling allows growers to get a good numeric value for what level of phosphorous and potassium is in a field to ensure that they aren't over-applying nutrients and minimizing losses of nutrient at the edge of field affecting water quality, while at the same time not under-applying resulting in less than maximum crop yields."
More information on soil sampling can be found on the fact sheet at http://ohioline.osu.edu/agf-fact/pdf/Soil_Sampling_to_Develop_Nutrient_Recommendations_AGF-513-12.pdf.