Wang Zhen, Sun Jun, Du Yadan, Niu Wenquan
College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, 712100, China.
Institute of Soil and Water Conservation, Northwest A&F University, Yangling, China.
J Sci Food Agric. 2022 Apr;102(6):2330-2341. doi: 10.1002/jsfa.11571. Epub 2021 Oct 25.
Poor inferior kernel grain filling is a challenge that limits summer maize yield. The effect and mechanism of conservation tillage on improving grain filling of inferior kernel in semi-arid rained areas remain uncertain and there has been little research on tillage management integrated with straw mulching to improve soil water content and photosynthesis in the Loess Plateau region. A 2 year (2019-2020) field experiment was established to study the impact of tillage practices on soil water content and summer maize root system morphology, photosynthetic capacity, inferior kernel grain filling, and grain yield. Treatments included reduced tillage (RT), no tillage (NT), and conventional tillage (CT).
Under RT and NT, the final 100-kernel weight and maximum and mean grain filling rates were higher than CT. Reduced tillage and NT increased soil water content at the jointing stage, silking stage and grain filling stage in comparison with CT. They increased root system morphology and dry matter accumulation, net photosynthetic rate, transpiration efficiency, and stomatal conductance in comparison with CT, and they also decreased intercellular CO concentration, and they increased chlorophyll content and above-ground dry matter accumulation in comparison with CT. Reduced tillage and NT increased evapotranspiration of maize, and ultimately, increased grain yield by 17% and 14%, respectively, in comparison with CT.
Conservation tillage could promote summer maize photosynthetic capacity and grain filling of inferior kernels by regulating soil water content and root system morphology. © 2021 Society of Chemical Industry.
下部籽粒灌浆不良是限制夏玉米产量的一个难题。在半干旱雨养地区，保护性耕作对改善下部籽粒灌浆的效果和机制尚不确定，在黄土高原地区，关于结合秸秆覆盖以提高土壤含水量和光合作用的耕作管理研究较少。开展了一项为期两年（2019—2020年）的田间试验，以研究耕作措施对土壤含水量、夏玉米根系形态、光合能力、下部籽粒灌浆及籽粒产量的影响。处理包括少耕（RT）、免耕（NT）和传统耕作（CT）。
与传统耕作相比，少耕和免耕处理下的最终百粒重、最大和平均籽粒灌浆速率更高。与传统耕作相比，少耕和免耕在拔节期、抽丝期和灌浆期提高了土壤含水量。与传统耕作相比，它们增加了根系形态和干物质积累、净光合速率、蒸腾效率和气孔导度，同时降低了细胞间CO浓度，还增加了叶绿素含量和地上部干物质积累。少耕和免耕增加了玉米的蒸散量，最终，与传统耕作相比，籽粒产量分别提高了17%和14%。
保护性耕作可通过调节土壤含水量和根系形态来促进夏玉米的光合能力和下部籽粒灌浆。© 2021化学工业协会。
