Long-Term Nitrogen and Phosphorus Fertilization of Irrigated Corn

Authors

A. Schlegel, Kansas State UniversityFollow
D. Bond, Kansas State UniversityFollow

Keywords

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

Abstract

Long-term research shows that phosphorus (P) and nitrogen (N) fertilizer must be applied to optimize production of irrigated corn in western Kansas. In 2018, N applied alone increased yields by 76 bu/a, whereas P applied alone increased yields by more than 17 bu/a. Nitrogen and P applied together increased yields up to 169 bu/a. This is 26 bu/a more than the 10-year average, where N and P fertilization increased corn yields up to 143 bu/a. Application of 120 lb/a N (with highest P rate) produced 97% of the maximum yield in 2018, which is slightly greater than the 10-year average. Application of 80 instead of 40 lb P₂O₅/a increased average yields 9 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 in the grain (AFNR_g) was 43% and apparent fertilizer phosphorus recovery in the grain (AFPR_g) was 62%.

Recommended Citation

Schlegel, A. and Bond, D. (2019) "Long-Term Nitrogen and Phosphorus Fertilization of Irrigated Corn," Kansas Agricultural Experiment Station Research Reports: Vol. 5: Iss. 7. https://doi.org/10.4148/2378-5977.7817