Abstract

Long-term research shows that phosphorus (P) and nitrogen (N) fertilizer must be applied to optimize the production of irrigated corn in western Kansas. In 2016, N applied alone increased yields by 85 bu/a, whereas P applied alone increased yields by only 12 bu/a. Nitrogen and P applied together increased yields up to 164 bu/a. This is 20 bu/a greater than the 10-year average, where N and P fertilization increased corn yields up to 144 bu/a. Application of 120 lb/a N (with the highest P rate) produced about 94% of maximum yield in 2016, which is similar to the 10-year average. Application of 80 instead of 40 lb P₂O₅/a increased average yields 6 bu/a. Average grain N content reached a maximum of 0.6 lb/bu, while grain P content reached a maximum of 0.15 lb/ bu (0.34 lb P₂O₅/bu). At the highest N and P rate, apparent fertilizer nitrogen recovery (grain) (AFNR_g) was 44% and apparent fertilizer phosphorus recovery (grain) (AFPR_g) was 62%.

Keywords: nitrogen fertilization, phosphorus fertilization, irrigated corn, long-term fertility, nutrient removal

How to Cite:

Schlegel, A. & Bond, H. D., (2017) “Irrigated Corn Response to Long-Term Nitrogen and Phosphorus Fertilization”, Kansas Agricultural Experiment Station Research Reports 3(5). doi: https://doi.org/10.4148/2378-5977.7401