稻田土壤微生物数量和酶活性对水碳调控的响应

为探究水碳调控稻田土壤微生物数量和酶活性变化,基于田间与室内试验,研究不同水碳处理稻田土壤微生物数量、过氧化氢酶和蔗糖酶的活性随土层深度的变化规律。结果表明,土壤过氧化氢酶活性随土层深度的增加呈现先增后减的趋势,土壤微生物数量和蔗糖酶活性随土层的加深而逐渐减小。与常规肥管理相比,有机肥施用和秸秆还田对稻田土壤过氧化氢酶活性无显著影响,而对土壤微生物数量和蔗糖酶活性影响较大。与淹水灌溉相比,控制灌溉提高了土壤过氧化氢酶活性,不同施肥管理条件下,控制灌溉对稻田土壤微生物数量和蔗糖酶活性的影响不一致。控制灌溉和有机肥施用、秸秆还田联合调控总体提高了稻田土壤微生物数量、过氧化氢酶和蔗糖酶的活性,且控制灌溉与有机肥施用结合效果更加明显。控制灌溉和有机肥施用、秸秆还田联合调控稻田0~40 cm土层土壤菌落数均值分别增加了1.73×10⁵~3.83×10⁵和2.33×10⁴~2.43×10⁵,土壤过氧化氢酶活性分别增加了1.82%~4.14%和2.95%~5.66%,土壤蔗糖酶活性分别增加了30.47%~64.25%和-25.04%~20.98%。

The Response of Soil Microbial Quantity and Enzyme Activity to Water and Carbon Control Regulation in Paddy Fields

To explore the changes of soil microbial quantity and enzyme activity in water and carbon control regulated paddy fields, the variation rules of soil microbial quantity, catalase activity and sucrase activity with soil depth under different water and carbon treatments were studied based on field and laboratory experiments. The results showed that with the increase of soil depth, soil catalase activity increased first and then decreased, and soil microbial quantity and soil sucrase activity decreased. Compared with conventional fertilization management, organic fertilizer and straw incorporation had no significant effect on soil catalase activity in paddy fields, while they had a greater impact on soil microbial quantity and soil sucrase activity. Compared with flooded irrigation, controlled irrigation improved soil catalase activity. Under different fertilization conditions, the effect of controlled irrigation on soil microbial quantity and soil sucrase activity in paddy fields was not consistent. In general, the combination of controlled irrigation with organic fertilizer application and straw incorporation could improve the amount of soil microbial quantity, catalase activity, and sucrase activity. Besides, the combined effect of controlled irrigation with organic fertilizer application was more prominent. When controlled irrigation was combined with organic fertilizer application and straw incorporation, the average values of soil colonies, soil catalase activity, and soil sucrase activity in the 0-40 cm soil layer increased by 1.73×10⁵-3.83×10⁵ and 2.33×10⁴-2.43×10⁵, 1.82%-4.14% and 2.95%-5.66%, 30.47%-64.25% and -25.04%-20.98%, respectively.