Grain Nutrient Removal Values for Corn, Soybeans, and Wheat.

Grain nutrient removal values vary depending on variety grown, soil, environment, management practices and other factors affecting plant growth. The current nutrient removal values used in the University of Missouri fertilizer recommendations are based on research data collected from late 1950’s to early 1970’s. Now with the high yielding varieties, the nutrient removal values from the late 50’s to early 70’s data may not hold true. Thus to revise the nutrient removal values used in the fertilizer recommendations, a survey was conducted for three growing seasons from 2006 – 2008 by collecting grain samples from corn, soybeans, and wheat in Missouri counties. The nutrient concentration and nutrient removal values for years 2006, 2007 and 2008 were different for all three crops. The grain nutrient concentration distribution for nitrogen (N) in corn followed somewhat similar pattern for the three years. However, this wasn’t the case in soybeans and wheat. The grain nutrient concentration for phosphorus (P) and potassium (K) were different for each year for all three crops. The average mean grain N, P, K concentration in percent were 1.46, 0.36, 0.48; 5.08, 0.48, 1.75; and 2.11, 0.40, 0.49 for corn, soybeans and wheat respectively. The spatial distribution in grain nutrient concentration for all three crops and relationship between the nutrient removal values and weather data will be presented.