耕作深度与秸秆还田对玉米氮代谢及产量形成的调控效应OA

In order to explore the regulation effects of tillage depth and straw returning on maize productivity in Northeast China,based on the micro-location experiment carried out in 2017,the field experiment was carried out from 2022 to 2023.Three tillage depths of 10 cm,30 cm,and 50 cm,and three straw returning methods of straw mixing(SM),straw burying(SB),and straw removal(SR)were set up to determine the activity of nitrogen me-tabolism enzymes in leaves,nitrogen content and dry matter accumulation in organs at the key growth stages of maize,and their effects on maize yield were analyzed.The results showed that compared with shallow tillage(10 cm),straw returning combined with moderate deep tillage(30 cm)could effectively improve the activities of gluta-mine synthetase and nitrate reductase in maize leaves,increase the content of free amino acids and soluble protein,and increase the average dry matter accumulation during the growth period by 2.26％,while too deep tillage depth(50 cm)could reduce the production advantage.Compared with SR,SM and SB could significantly enhance the abil-ity of leaf nitrogen metabolism.The grain nitrogen uptake at the maturity stage was increased by 12.95％and 26.21％,respectively.The grain yield in 2022 increased by 1.45％and 6.52％,respectively,and the yield in 2023 increased by 9.45％and 14.12％,respectively.In summary,shallow tillage(10 cm)combined with straw mixing returning and appropriate deep tillage(30 cm)combined with straw burial returning can maximize maize yield,which can be used as a suitable maize tillage mode in the southern part of Northeast China.