中国农业科学2025，Vol.58Issue(5)：929-942,14.DOI:10.3864/j.issn.0578-1752.2025.05.009
水氮耦合对西北旱区覆膜农田土壤有机碳、氮矿化的影响
Effects of Water-Nitrogen Coupling on the Mineralization of Organic Carbon and Nitrogen for Mulched Farmland Soils in the Arid Regions of Northwest China
摘要
Abstract
[Objective]This study aimed to clarify the effects of irrigation and nitrogen application on soil fertility,to explore the characteristics of organic carbon and nitrogen mineralization and their influencing factors in mulched farmland soils under different water and nitrogen conditions,so as to provide the theoretical basis for water and nitrogen control measures for mulched farmland crops in the Northwest of China.[Method]In this study,on the basis of five consecutive years of field trials of winter wheat-summer maize with nitrogen application in mulching,the soil samples were collected under three nitrogen application levels of 0(N0),180 kg·hm-2(N1)and 360 kg·hm-2(N2),and three soil moisture gradients,namely,40%of the field holding capacity(W0),60%of the field holding capacity(W1),and 100%of the field holding capacity(W2),were set up for indoor organic carbon and nitrogen mineralization.Then,the effect of water-nitrogen coupling on soil organic carbon and nitrogen mineralisation in mulched farmland were analyzed.[Result]Increasing water content significantly increased the cumulative soil carbon mineralization(Cmin),carbon mineralization rate,cumulative net soil nitrogen mineralization(Nmin),nitrogen mineralization rate,and potential mineralized nitrogen(Np).Cmin,Nmin and Np all showed a tendency to increase and then decrease with increasing nitrogen application.At the end of incubation,Cmin was the highest under N1W1 treatment(1 781.00 mg·kg-1),which was significantly higher than that under other treatments(N0W0,N0W1,N0W2,N1W0,N1W2,N2W0,N2W1,N2W2)by 8.8%to 51.8%,respectively,and its Nmin was also maintained at a relatively high level(29.52 mg·kg-1),while the potential mineralized carbon(5 883.79 mg·kg-1)and Np(30.74 mg·kg-1)were also maintained at a relatively high level.The random forest algorithm indicated that soil microbial carbon(MBC),soil microbial nitrogen,dissolved organic carbon,organic carbon,and total dissolved nitrogen were the important factors affecting Cmin and Nmin.MBC showed a tendency of increasing and then decreasing with the increase of soil moisture,and the MBC content under W1 significantly increased by 60.1%-340.0%and 3.1%-6.7%,respectively.The structural equations showed that soil moisture had a direct positive effect(0.70)and an indirect positive effect(0.55)on soil carbon mineralization,while the nitrogen application had a direct positive effect(0.90)and an indirect negative effect(0.24)on soil nitrogen mineralization.[Conclusion]From the perspective of soil carbon and nitrogen mineralization,this study recommended 60%field capacity and 180 kg N·hm-2 as suitable water and nitrogen regulation strategies for mulched farmland in the dryland of Northwest China.关键词
施氮量/土壤水分/碳矿化/净氮矿化/矿化动力学/西北旱区Key words
nitrogen application rate/soil moisture/carbon mineralization/net nitrogen mineralization/mineralization kinetics/arid regions of Northwest China引用本文复制引用
赵彤彤,谷晓博,谭川东,延廷霖,李晓雁,常甜,杜娅丹..水氮耦合对西北旱区覆膜农田土壤有机碳、氮矿化的影响[J].中国农业科学,2025,58(5):929-942,14.基金项目
国家重点研发计划(2021YFD1900700)、陕西省重点研发计划(2023-YBNY-040) （2021YFD1900700）
