Nitrogen fertilizer and tillage intensity affected winter wheat macronutrient uptake and utilization efficiencies

Abstract

AbstractApplication of N fertilizer and no‐tillage (NT) can increase winter wheat (Triticum aestivum L) production through improvements in plant available soil water and nutrient availability. However, long‐term tillage and N management interaction effects on winter wheat nutrient uptake are not well known. The objective of this study was to quantify winter wheat grain yield, macronutrient removal, and utilization responses to N fertilizer application and tillage intensity. The study was conducted in 2019 and 2020 at Hays, Kansas after 45 years of tillage and N fertility experiment. Treatments were a combination of two tillage practices (CT, conventional tillage; NT) and four rates of N (0, 45, 90, and 134 kg ha−1). Results showed a significant tillage and N fertilizer interaction effect on wheat grain yield, nutrient removal (NR) (grain‐N, ‐P, ‐K, ‐Mg; stover‐K, and total P), and nutrient concentration (stover‐K and ‐S). Two different quadratic models fit the N rate‐to‐yield relation for CT and NT with yields of 4.3 and 5.2 Mg ha−1 at agronomic optimal N rates of 119 and 199 kg N ha−1, respectively. This suggests that the N rates were not high enough to predict optimum N rate for NT in this environment. With an average yield of 3.30 Mg ha−1, wheat removed about 113 kg N ha−1, 17 kg P ha−1, 56 kg K ha−1, 7 kg Ca ha−1, 8 kg Mg ha−1, and 8 kg S ha−1, irrespective of tillage practice. Grain yields and NR were greater for CT at smaller N rates (<90 kg N ha−1) and for NT at greater N rates (>90 kg ha−1). Findings of the study suggest that adequate N fertility (>90 kg ha−1) should be maintained to improve grain yield, nutrient uptake, and utilization efficiency in dryland NT wheat production systems.