摘要：研究东北黑土区不同还田方式影响下玉米秸秆及其纤维素、半纤维素与木质素成分的腐解动态，分析秸秆碳、氮、磷、钾养分的释放规律。采用尼龙网袋法，在吉林省公主岭市黑土区布设秸秆不同还田方式与长度双因素秸秆腐解模拟试验，主因素为还田方式（深度），包括覆盖（FG，0cm）、深翻（SF，30cm）与旋耕（XG，0-15cm），副因素为秸秆长度，分别为5-10cm（S）、15-20cm（M）、25-30cm（L），共9个处理。经过693天的试验，不同尺寸玉米秸秆覆盖、深翻与旋耕处理秸秆累计腐解率平均分别为69.2%、87.2%和84.6%，0-369天表现为快速腐解期（腐解54.7%-68.2%），369-693天表现为慢速腐解期（腐解14.5%-20.5%）。双库指数模型能较好地拟合各处理秸秆腐解率随时间的变化，覆盖、深翻与旋耕处理秸秆腐解速率常数分别为0.31%、0.38%和0.39%。第693天时，深翻与旋耕处理秸秆各纤维成分腐解率接近，明显高于覆盖，特别是木质素腐解率，较覆盖还田高26.4-27.4个百分点，不同秸秆尺寸间各纤维组分腐解率的变化规律不明显。在第693天时，三种纤维成分的腐解率均随着秸秆尺寸增加而降低，且S和M处理间未表现出显著差异。不同还田方式秸秆全碳、全氮、全磷、全钾养分累计释放率均表现为深翻＞旋耕＞覆盖，衰减指数方程很好地拟合了不同还田方式玉米秸秆全碳、全氮、全磷、全钾残留量随时间的变化过程。在为期2年的腐解过程中，深翻与旋耕还田秸秆腐解率、腐解速率及三种纤维成分的腐解率均显著高于覆盖还田，当还田秸秆的尺寸大于25cm后，秸秆及其纤维组成的腐解率显著降低。与秸秆覆盖还田相比，深翻和旋耕还田更利于秸秆养分的释放。双库指数模型与衰减指数方程很好地拟合了不同秸秆还田方式玉米秸秆腐解与养分衰减变化过程。

Abstract: This study investigated the decomposition dynamics of maize straw and its cellulose, hemicellulose, and lignin components under different straw return methods in the black soil region of Northeast China. The release patterns of carbon, nitrogen, phosphorus, and potassium nutrients from the straw were also analyzed. A nylon mesh bag method was used to simulate the decomposition of maize straw under different returning methods and straw lengths in black soil region of Gongzhuling city, Jilin Province. The main factor of this experiment was the straw returning method (buried depth), which included mulching (FG, 0 cm), deep plowing (SF, 30 cm), and rotary tillage (XG, 0-15 cm), while the secondary factor was straw length, with three levels: 5-10 cm (S), 15-20 cm (M), and 25-30 cm (L). A total of 9 treatments were established. After 693 days of experimentation, the cumulative decomposition rates of maize straw under mulching, deep plowing, and rotary tillage treatments averaged 69.2%, 87.2%, and 84.6%, respectively. The period from 0 to 369 days was characterized as a rapid decomposition phase (54.7%–68.2% decomposition), while the period from 369 to 693 days was a slow decomposition phase (14.5%–20.5% decomposition). The two-pool exponential model effectively simulated the changes in straw decomposition rates over time for all treatments The decomposition rate constants for the mulching, deep plowing, and rotary tillage treatments were 0.31%, 0.38%, and 0.39%, respectively. By day 693, the decomposition rates of various fibrous components under deep plowing and rotary tillage treatments were similar and significantly higher than those under mulching treatment. Specifically, the lignin decomposition rate was 26.4–27.4 percentage points higher than that under mulching. No clear pattern was observed in the decomposition rates of fibrous components across different straw sizes. By day 693, the decomposition rates of all three fibrous components decreased with increasing straw size, with no significant differences between the S and M treatments. The cumulative release rates of total carbon, nitrogen, phosphorus, and potassium nutrients under different straw return methods followed the order: deep plowing > rotary tillage > mulching. The exponential decay equation adequately described the changes in the residual amounts of these nutrients over time. Over the two-year decomposition process, the straw decomposition rates, decomposition rate constants, and decomposition rates of the three fibrous components were significantly higher under deep plowing and rotary tillage treatments compared to mulching treatment. When the straw size exceeded 25 cm, the decomposition rates of straw and its fibrous components significantly decreased. Compared to straw mulching, deep plowing and rotary tillage facilitated greater release and supply of straw nutrients. The two-pool exponential model and exponential decay equation effectively simulated the decomposition of maize straw and nutrient decay under different straw return methods.

秸秆还田项目(07)、吉林省农业科技创新工程项目(CXGC2024ZD016)、国家现代农业产业技术体系(CARS-07-G-6),吉林省留学人员科技创新创业项目(优秀类)