Winter wheat yield stability as affected by fertilizer‐N, tillage, and yield environment

Abstract

AbstractWith an increase in the frequency of hot‐dry‐windy weather and reported significant increase in winter wheat (Triticum aestivum L.) in‐season average temperatures, it is important to understand how soil management affects yield stability. This study quantified the combined effects of tillage and fertilizer‐N on winter wheat yield stability in a wheat–sorghum [Sorghum bicolor (L.) Moench]–fallow crop rotation. The research was conducted from 1975 to 2022 and the experimental design was a randomized complete block with a split‐split‐plot arrangement. Crop phases were the main plots, tillage (conventional tillage [CT], reduced tillage [RT], and no‐tillage [NT]) in the sub‐plot, and N application rates (0, 22, 45, and 67 kg N ha−1 or 0, 45, 90, and 134 kg N ha−1) in the sub‐sub‐plot. Results showed winter wheat yield under NT increased by 0.8 Mg ha−1, compared with about 1.1 Mg ha−1 for CT and RT, when environmental average increased by 1 Mg ha−1 for N rates ≤90 kg ha−1. Yields with CT and RT increased by 0.8 Mg ha−1, compared with about 1.1 Mg ha−1 rate for NT, when environmental average increased by 1 Mg ha−1 for N >90 kg ha−1. In 30%–52% of the time, CT wheat yield was greater than NT, but yield advantage with CT decreased as fertilizer‐N rate increases. Yield stability of winter wheat varied by tillage and fertilizer rate. We concluded that NT wheat required greater N rates to reach the same yield potential as CT and RT, and long‐term CT or RT wheat at 45 kg N ha−1 was most stable.