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

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, supplemental irrigation, and plastic mulching) on crop yields, using data from a 5-yr 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-yr 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%), and high density, improved variety, and irrigation contributed 9.9, 6.9, and 5.1% increases 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 a yield level of 8-11 Mg ha(-1) in the studied area. In conclusion, reducing the 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 will help develop adaptive management practices for increasing crop yield stability in other semi-arid regions.

Automated summary

The study found that optimizing multiple agronomic factors significantly increased maize yield, with plastic mulching contributing the most to yield increase. In the study area, a nitrogen input of 225 kg N/ha was sufficient to achieve a yield level of 8-11 Mg/ha.