Objectives Water and fertilizer use efficiencies of spring maize production system are low in the valley plains of eastern Loess Plateau. For this reason, we studied the effects of different surface mulching measures on yield, nitrogen translocation efficiency, nitrogen use efficiency and economic benefit of spring maize, in order to provide scientific management measures for high yield and high efficiency of spring maize production in this region.
Methods The study was based on a long-term experiment started in 2014 in Dongyang Experimental Demonstration Base of Shanxi Agricultural University in Jinzhong City, Shanxi Province, with spring maize cultivar ‘Dafeng 30’ as test materials. The four treatments included fertilization without mulching (NM), with plastic film mulching (FM), with straw mulching (SM), and without mulching and fertilization control (CK). In 2021 and 2022, the photosynthetic characteristics, dry matter and nitrogen accumulation of spring maize were measured at different growth stages, and the grain yield, and economic benefit were investigated at harvest.
Results Compared to NM, FM treatment improved leaf chlorophyll content, area index, and effective light interception of spring maize at pre-silking periods, but significantly reduced them at the post-silking periods. FM treatment led to over 70% of lodging rate, and 45.41% lower shoot N accumulation at post-silking periods, impacting the yield formation in 2021. SM treatment improved leaf chlorophyll content, area index, and effective light interception across the whole growing period of maize, thus increased the dry matter and N accumulation at pre-silking periods, resulting high N uptake and nitrogen use efficiency of maize. Compared with NM, FM and SM treatment increased grain yield by 6.18%−15.26%; FM treatment significantly increased the shoot N uptake, N recovery efficiency, agronomy efficiency and partial factor productivity by 21.84%, 31.59%, 28.86%, and 16.18% in 2022; SM treatment increased them by 13.86%, 18.48%, 19.21% and 12.14% in 2021, and 25.54%, 36.92%, 33.86% and 18.99% in 2022, respectively. Compared with FM, SM treatment increased grain N uptake by 27.89% and 9.25% in 2021 and 2022, the grain N uptake and N recovery efficiency by 18.57% and 15.58%, and increased yield and economic benefit by 8.55% and 12.48%, respectively.
Conclusion Straw mulching performs better than plastic film mulching in coordinating the growth of pre- and post-silking stage, decreasing lodging rate, thereby improving nitrogen use efficiency, yield and economic benefit of spring maize. In addition, straw can provide additional nitrogen and carbon for soil, and has no risk of micro-plastics pollution. Therefore, straw mulching should be used to replace plastic film for the efficient utilization of water and fertilizer in the spring maize production in the valley plain of eastern Loess Plateau.
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