Corn response to tillage and side‐dress nitrogen management on claypan soil

Abstract

Abstract Since information islimited regarding N management and tillage options for corn (Zea mays L.) grown on claypan soil in the eastern Great Plains, the objective of this study was to determine the effect of preplant and side‐dress N applications on corn grown in conventional‐ and no‐till systems. The yield penalty for no‐till grown corn was nearly 20% due partially to an 8% stand reduction, but also to lower kernel weight and kernels ear–1 than with conventional till. These yield and yield component reductions with no‐till may be because of lower dry matter production and N uptake throughout the growing season. The general lack of interactions suggest that N management system effects on corn were not influenced by tillage system selection. Fertilizing with N more than doubled corn yields primarily by nearly doubling the number of kernels ear–1, but with additional increases in kernel weight and average number of ears plant–1. Averaged over years, split‐N resulted in up to 15% greater yield, and additional side‐dress N resulted in up to 28% greater yield than when 168 kg N ha–1 was applied only at preplant, with no yield reduction for delaying side‐dress application from V6 to V10. The relationship of relative N uptake to relative corn yield approached a direct 1:1 relationship by R1 (silking). The decision of whether to split‐apply fertilizer N or to add additional N, regardless of tillage system, will likely be influenced by economic factors, but side‐dress N applications may extended to the V10 stage with no yield penalty.