Re-thinking corn phosphorus requirements: Can we optimize timing to get by with less?

Abstract

Below-optimum soil phosphorus (P) levels limit crop production, while excess P transported from agricultural landscapes to surface water contributes to eutrophication. Improvements in P-utilization efficiency (PUE) would benefit agro-economic efficiency and water quality. This paper examines the potential for increasing PUE in corn (Zea mays) by altering application timing. The data were utilized from a previous study on P application timing in soil-less media for precise control. Minimum P uptake with no loss in grain yield occurred when sufficient P was exclusively applied between V6 and R1. This resulted in 15% less P uptake compared to receiving sufficient P throughout all growth stages. In contrast, sufficient P application exclusively from R1 to R6 produced nearly half the grain yield and PUE compared to V6 to R1 application. The results suggest that P application at around V6 could allow for reduced P application rates by “feeding the plant” rather than “feeding the soil.”