地膜覆盖对旱作春玉米农田土壤微生物碳源代谢的影响

土壤微生物碳源代谢特征是评价土壤质量变化的重要指标。依托山西省东部晋中市寿阳县农业环境与作物高效用水科学观测试验站，采用Biolog-ECO微孔板技术探究覆膜（FM）与裸地不覆膜处理（LD）对旱作春玉米拔节期、灌浆期和收获期3个关键生育期不同土层深度下（0-10 cm、10-20 cm和20-30 cm）土壤微生物碳源代谢的影响。结果表明：1） FM措施可以显著增加土壤微生物对碳源的利用能力，显著提高了土壤微生物的优势度指数，但降低了土壤微生物的均匀度指数。2）在0-10 cm和10-20 cm土层，FM与LD处理土壤微生物碳源利用情况均表现为灌浆期较高，而20-30 cm土层，表现为收获期较高，差异均主要体现在碳水类、羧酸类、氨基酸类3大类碳源上。3）拔节期和灌浆期0-10 cm土层中FM处理的土壤微生物碳源利用能力显著高于LD处理；然而收获期0-10 cm土层中恰好相反，呈现出LD处理下土壤微生物碳源利用能力显著高于FM处理。4）此外，Pearson相关分析表明，FM处理土壤微生物对碳水类碳源和羧酸类碳源2大类碳源的利用能力主要与土壤有机碳（SOC）和全氮（TN）含量相关性较好，呈现出正相关关系；对氨基酸类碳源的利用能力主要与土壤含水量、pH、SOC、NH₄⁺-N和NO₃^--N含量相关性较好。LD处理下，土壤微生物对碳水类、羧酸类和氨基酸类碳源的利用能力与土壤中TN含量的相关性较好，且呈现正相关关系。

Effects of film mulching on soil microbial carbon source metabolism in dry-farmland

The metabolic characteristics of soil microbial carbon source are important indexes to evaluate the change of soil quality. Based on the scientific observation and experiment station of agricultural environment and efficient water use for crops in Shouyang County, Jinzhong City, eastern Shanxi Province, this study used Biolog-ECO microplate technology to explore the effects of film mulching (FM) and no film mulching (LD) on the carbon source metabolism of soil microorganisms in different soil depths (0-10 cm, 10-20 cm and 20-30 cm) in 3 key growth stages of dry-farming spring corn. The results show that:1) the FM measures can significantly increase the utilization ability of soil microorganisms to carbon sources, significantly improve the richness index of soil microorganisms, but reduce the evenness index of soil microorganisms. 2) In 0-10 cm and 10-20 cm soil layers, the utilization of microbial carbon sources in FM and LD treatments were higher in filling period, while in 20-30 cm soil layer, the harvest period was higher, and the differences were mainly reflected in 3 types of carbon sources:carbonaceous water, carboxylic acids and amino acids. 3) The utilization capacity of microbial carbon source in 0-10 cm soil layer of FM treatment was significantly higher than that of LD treatment at jointing stage and filling stage; However, in the 0-10 cm soil layer at harvest time, the oppositely is true, showing that the utilization capacity of soil microbial carbon source under LD treatment is significantly higher than that under FM treatment. 4) In addition, Pearson correlation analysis showed that under FM treatment in this study, the utilization ability of soil microorganisms to 2 kinds of carbon sources, namely, carbohydrate carbon source and carboxylic carbon source, had a good correlation with soil organic carbon(SOC) and total nitrogen(TN) content, showing a positive correlation; The utilization ability of amino acid carbon sources is mainly related to soil water content, pH, SOC, NH₄⁺-N and NO₃^--N content. Under LD treatment, the utilization ability of carbon sources such as carbonaceous water, carboxylic acids and amino acids by soil microorganisms had a good correlation with TN content in soil, and showing a positive correlation.