Evaluating agronomic factors for maize production in a semi‐arid Loess Plateau

Abstract

Crop production is often affected by multiple agronomic factors. However, little has been reported on the synergistic effects of multiple factors on crop production. Here, we reported the effects of five factors (i.e., variety, planting density, nitrogen application, This article is protected by copyright. All rights reserved.supplementary irrigation and plastic mulching) on crop yields, using data from a 5-year experiment at Dongyang, Shanxi province of China. An incomplete factorial design with these factors comprised 12 treatments, including two controls: optimized technology (OT) and conventional technology (CT), comprising all five factors applied at the added or subtracted level, respectively. The result showed that, on 5-year average, OT significantly increased maize yield by 3.5 Mg ha -1 (44.3% more) as compared to CT (7.9 Mg ha -1 ), showing a huge potential for increasing yields. Among the five factors, plastic mulching contributed the most in yield increase (11.5%), high density, improved variety and irrigation contributed 9.9%, 6.9% and 5.1% increase in yield, respectively. There were no significant differences in yield between two N input levels (i.e., 225 and 300 kg N ha -1 ), suggesting the N input of 225 kg N ha -1 was sufficient to realize yield level of 8-11 Mg ha -1 in the studied area. In conclusion, reducing yield gap can only be achieved by optimizing multiple factors simultaneously because the effects of single measure are relatively small and inconsistent among years. The results of our study would help develop adaptive management practices for increasing crop yield stability in other semi-arid regions.