摘 要：为明确覆膜与不同秸秆还田模式对吉林省东部冷凉区玉米产量形成的生理机制，本研究以玉米品种松玉 438为试验材料，采用裂区试验设计，设覆膜（F）与不覆膜（NF）为主区，秸秆离田（LT）、粉耙还田（FB）、深翻还田（SF）、深混还田（SH）为副区，测定不同处理下玉米群体叶面积指数（LAI）、干物质累积量（DM），叶片净光合速率（Pn）、抗氧化酶活性、渗透调节物质含量，根系伤流液特性及产量变化。结果表明：覆膜可显著提高玉米群体LAI、DM和叶片Pn；其中，秸秆深混还田覆膜（SHF）处理在玉米R3期LAI、DM分别较秸秆离田覆膜（LTF）提高10.51%、26.62%；覆膜协同秸秆深混还田可显著提升超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性，降低丙二醛（MDA）含量，增加脯氨酸（Pro）积累量；SHF处理的根系伤流强度及及伤流液中细胞分裂素（CTK）、游离氨基酸（FAA）、可溶性糖（SS）含量显著提升，脱落酸（ABA）含量显著降低。SHF产量达11583.98 kg hm?2，较LTF增产2.4%，较秸秆离田不覆膜（LT）增产13.8%。综上，可降解地膜覆盖结合秸秆深混还田可通过增强根系活力、提升光合与抗氧化能力、促进同化物积累实现高产，该技术模式可作为冷凉区玉米高产栽培的核心技术。

Abstract: To clarify the physiological mechanism underlying the effects of mulching combined with different straw returning modes on maize yield formation in the cool-temperate region of eastern Jilin Province, this study used maize cultivar Songyu 438 as the experimental material and adopted a split-plot experimental design. The main plots were set as mulching (F) and no mulching (NF), while the subplots included four straw returning modes: straw removal (LT), straw crushing and harrowing returning (FB), straw deep ploughing returning (SF), and straw deep mixing returning (SH). The variations in population leaf area index (LAI), dry matter accumulation (DM), leaf net photosynthetic rate (Pn), antioxidant enzyme activities, osmotic adjustment substance contents, root bleeding sap characteristics and yield of maize under different treatments were determined.The results showed that mulching significantly increased the population LAI, DM and leaf Pn of maize. Specifically, compared with straw removal with mulching (LTF), the straw deep mixing returning with mulching (SHF) treatment increased the LAI and DM by 10.51% and 26.62% respectively at the maize R3 stage. Moreover, mulching combined with straw deep mixing returning significantly enhanced the activities of superoxide dismutase (SOD) and catalase (CAT), reduced malondialdehyde (MDA) content, and increased proline (Pro) accumulation. The SHF treatment significantly improved root bleeding sap intensity, as well as the contents of cytokinin (CTK), free amino acids (FAA) and soluble sugars (SS) in the bleeding sap, while markedly decreasing abscisic acid (ABA) content. The yield of the SHF treatment reached 11583.98 kg·hm-2, which was 2.4% higher than that of LTF and 13.8% higher than that of straw removal without mulching (LT).In conclusion, degradable film mulching combined with straw deep mixing returning can achieve high yield by enhancing root activity, improving photosynthetic and antioxidant capacities, and promoting assimilate accumulation. This technical mode can be used as the core cultivation technology for high-yield maize production in cool-temperate regions.

吉林省科技发展计划项目（20240303026NC）