Improving wheat yield by optimizing seeding and fertilizer rates based on precipitation in the summer fallow season in drylands of the Loess Plateau

Abstract

Listen

Translate article

Precipitation has been recognized as the dominant factor driving crop grain yields and large yield variations in drylands, which suggests that some agricultural management practices can be optimized to achieve high yields and benefits. In this study, we investigated 804 farmers' wheat fields from 2015 to 2018 in the dryland area of the Loess Plateau in China and analyzed the relationships between wheat yield and the influence factors (including precipitation, wheat sowing rate, fertilizer inputs, and soil nutrients) to propose optimized agricultural management practices for wheat production. The results showed that wheat grain yield followed a linear plateau pattern relative to the precipitation in the summer fallow season, with a yield of 5344 kg ha−1 obtained at a precipitation of 203 mm. In the L203 group (precipitation in the summer fallow season less than 203 mm), the Low-yield subgroup (0–33th in grain yield group (in order from low to high)) had a lower sowing rate, kernel weight, kernel number and spike number than the High-yield subgroup (68–100th in grain yield group); different levels of phosphorous (P) and potassium (K) fertilizer overuse were found among the three yield subgroups. However, in the H203 group (precipitation in the summer fallow season greater than 203 mm), differences in only kernel and spike numbers and nitrogen (N) fertilizer application rate were observed among the Low-, Moderate-, and High-yield subgroups. Additionally, there were no differences in the soil organic matter (SOM), total N or pH in the three subgroups in either L203 or H203, but significant differences in soil mineral N, available P and K were observed among the three subgroups (except mineral N in L203). Based on these results, the wheat sowing rate and fertilizer input rates can be optimized to increase wheat yield and farmers’ income and promote agricultural management for dryland wheat production on the Loess Plateau.