Author
WORTMANN, C - UNIV OF NEBRASKA-LINCOLN | |
DOBERMANN, A - INT'L RICE RESEARCH INST | |
FERGUSON, R - UNIV OF NEBRASKA-LINCOLN | |
HERGERT, G - UNIV OF NEBRASKA-LINCOLN | |
SHAPIRO, C - UNIV OF NEBRASKA-LINCOLN | |
Tarkalson, David | |
WALTERS, D - UNIV OF NEBRASKA-LINCOLN |
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/17/2008 Publication Date: 5/1/2009 Citation: Wortmann, C.S., Dobermann, A.R., Ferguson, R.B., Hergert, G.W., Shapiro, C.A., Tarkalson, D.D., Walters, D.T. 2009. High-yielding corn response to applied phosphorus, potassium, and sulfur in Nebraska. Agronomy Journal. 101(3):546-555. Interpretive Summary: Nutrient management recommendations may change as yield levels and efficiency of crop production increase. Recommendations for phosphorus (P), potassium (K), and sulphur (S) were evaluated using results from 34 irrigated corn trials conducted in diverse situations across Nebraska. The estimated critical soil Bray-1 P level for corn was 20 mg/kg when the previous crop was corn compared to 10 mg/kg when corn followed soybean. Soil test K was generally high with only three site-years <125 mg/kg. Over all trials, application of 40 kg K/ha resulted in a 0.2 Mg/ha mean grain yield decrease. Application of 22 kg S/ha did not result in significant yield increase in any trial. Soil test results accounted for twice as much variation in nutrient uptake when soil organic matter and pH were considered in addition to the soil test nutrient values. The results indicate a need to revise the current recommendation for P, to maintain the current K and S recommendations, and to use soil organic matter and pH in addition to soil test nutrient values in estimating applied nutrient requirements for irrigated high yield corn production. Technical Abstract: Nutrient management recommendations may change as yield levels and efficiency of crop production increase. Recommendations for P, K, and S were evaluated using results from 34 irrigated corn (Zea mays L.) trials conducted in diverse situations across Nebraska. The mean yield was 14.7 Mg/ha with adequate fertilizer applied. The median harvest index values were 0.52, 0.89, 0.15, and 0.56 for biomass, P, K, and S, respectively. Median grain yields were 372, 49, and 613 kg/kg of above-ground plant uptake of P, K, and S, respectively. The estimated critical Bray-1 P level for corn response to 20 kg P/ha was 20 mg/kg when the previous crop was corn compared to 10 mg/kg when corn followed soybean (Glycine max L.). Soil test K was generally high with only three site-years <125 mg/kg. Over all trials, application of 40 kg K/ha resulted in a 0.2 Mg/ha mean grain yield decrease. Application of 22 kg S/ha did not result in significant yield increase in any trial. Soil test results accounted for twice as much variation in nutrient uptake when soil organic matter (SOM) and pH were considered in addition to the soil test nutrient values. The results indicate a need to revise the current recommendation for P, to maintain the current K and S recommendations, and to use SOM and pH in addition to soil test nutrient values in estimating applied nutrient requirements for irrigated high yield corn production. |