生物炭施用方式对黑土和潮棕壤养分及氮磷转化相关酶活性的影响

Effects of biochar application patterns on soil nutrients and nitrogen- and phosphorus-related enzyme activities in Phaeozem and Luvisol

为探明不同生物炭施用方式对农田土壤养分含量及元素转化的影响,通过设置在黑土和潮棕壤的两个为期5年的田间定位试验,研究每年低量施用(AL,22.5 t·hm^(-2)·a^(-1))和间隔性高量施用(IH,112.5 t·hm^(-2)·5 a^(-1))玉米秸秆生物炭对土壤碳、氮、磷含量,土壤生物学性质及氮磷转化相关酶活性的影响,以期为秸秆的资源化利用和农田土壤地力提升提供科学依据。结果表明:两种施用方式间比较,黑土AL处理的全碳和有机氮含量(31.55和1.89 g·kg^(-1))显著高于IH处理(25.77和1.71 g·kg^(-1));与对照相比,黑土AL处理脱氢酶活性降幅(26.75 mg·kg^(-1)·24 h^(-1))大于IH处理(17.69 mg·kg^(-1)·24 h^(-1)),而潮棕壤AL处理蛋白酶活性增幅(11.77 mg·kg^(-1)·h^(-1))却低于IH处理(29.95 mg·kg^(-1)·h^(-1))。与潮棕壤相比,生物炭施用对黑土全碳和有机氮含量的提升较大。生物炭的施用显著提高了潮棕壤脱氢酶和蛋白酶的活性,却显著降低了黑土脱氢酶活性。土壤类型和生物炭施用方式对土壤碳氮含量、微生物代谢活性及氮磷转化相关酶活性存在显著的交互作用。总体来说,土壤类型和生物炭添加对土壤理化性质和微生物学特性产生了显著的影响,这为秸秆资源化利用和土地管理提供了重要的参考价值。

We investigated the effects of different biochar application patterns on soil nutrient contents and element transformation, with soil samples being collected from two five-year field experiments in Phaeozem and Luvisol amended with biochar at annual low-rate(AL, 22.5 t·hm^(-2)·a^(-1)) and intervalic high-rate(IH, 112.5 t·hm^(-2)·5 a^(-1)). Changes of soil total carbon(C), nitrogen(N) and phosphorus(P) contents as well as the related enzyme activities were measured under different biochar application patterns to provide fundamental information for the straw utilization and soil fertility improvement in agroecosystem. Results showed that total C and organic N contents in AL treatment were significantly higher than those in IH treatment in Phaeozem soil. Compared with the control, the decreases of dehydrogenase activity in AL treatment was more pronounced than that in IH treatment in Phaeozem soil, and the increases of protease activity in IH treatment was pronounced than that in AL treatment in Luvisol. Compared with Luvisol soil, the application of biochar had stronger effect on total soil C and organic N contents in Phaeozem soil. Application of biochar significantly increased the activities of soil dehydrogenase and protease in Luvisol soil, but decreased the activity of soil dehydrogenase. Soil types and biochar application patterns interacted to affect soil C and N contents, microbial metabolic activity, N-and P-related enzyme activities. In summary, soil types and biochar addition affected soil properties and microbial characteristics, which would provide important information for straw application and soil management.