Effects of drip irrigation methods on yield and water productivity of maize in Northwest China

Abstract Water scarcity adversely affects the growth and yield of summer maize in the semi-arid region of Northwest China, and the application of irrigation technology to save water is an effective method for sustainable agricultural development in the area. In order to evaluate the potential of different drip methods for increasing grain yield and water productivity (WP), a 2-year (2018–19) field experiments was conducted to study the effects of various drip irrigation methods on the biomass accumulation and translocation and grain filling progress. The experiment involved three drip irrigation methods: conventional surface drip irrigation (CDI), subsurface drip irrigation (SDI) and alternate surface and subsurface drip irrigation in the soil vertical profile (ADI). The results showed that the ADI treatment had the highest above-ground accumulation of biomass at the maturity stage. However, no statistically significant differences were observed in all the treatments. The contribution of post-silking biomass to grain yield was ADI > SDI > CDI. Based on the two-year average analysis of data, the contribution of post-silking biomass to the grain yield in ADI was 3.6% and 7.0% higher than that in SDI and CDI, respectively. The maximum grain filling rate and the mean grain filling rate were the highest in the ADI, followed by SDI with CDI as the lowest. The active grain filling period and effective grain filling time were the highest under ADI and the lowest under CDI. There was a positive correlation between the active grain filling period and effective grain filling time. The ADI treatment decreased the grain number per spike but significantly increased the kernel weight. Two years of mean data demonstrated that the grain yield of the ADI was 6939.5 kg ha−1, which corresponded to increases of 4.8% and 13.3% from 6625.0 and 6126.5 kg ha−1 for SDI and CDI, respectively. For WP, the difference between treatments followed a similar pattern in 2018 and 2019, i.e., the ADI was significantly higher than the SDI, while the SDI was significantly higher than the CDI. Taken together, in addition to its potential for saving water, ADI has the additional advantage of promoting yield. Furthermore, the findings can contribute to a better understanding of the mechanism of biomass accumulation and grain filling process responses to drip irrigation methods.