The enhancements of pore morphology and size distribution by straw return are mediated by increases in aggregate-associated carbon and nitrogen  

作　　者：Ying Zhao Xiaozeng Han Chen Qiu Wenxiu Zou Xinchun Lu Jun Yan Xu Chen 

机构地区：[1]State Key Laboratory of Black Soils Conservation and Utilization,Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences,Harbin 150081,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Wenshan Soil and Fertilizer Workstation,Wenshan 663000,China

出　　处：《Journal of Integrative Agriculture》2025年第4期1562-1576,共15页农业科学学报(英文版)

基　　金：the Chinese Academy of Sciences for their financial support and research facilities;funded by the National Key Research and Development Program of China(2022YFD1500100);the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA28070100);the China Agriculture Research System of MOF and MARA(CARS04)。

摘　　要：The accumulation of soil organic carbon(SOC)and total nitrogen(TN)is easily accomplished by returning crop straw,which strongly affects the formation and pore structure of aggregates,especially in black soil.We returned maize straw at different rates(6,000,9,000,12,000 and 15,000 kg ha^(-1))for nine years to investigate its influence on the SOC and TN contents in the SOC fractions of aggregates by combining size and density fractionation.Their subsequent influences on pore morphology and size distribution characteristics were examined using X-ray microcomputed tomography scanning(μCT).The results showed that returning straw significantly increased the contents of C and N in the SOC fractions of aggregates,especially at the return rates of 12,000 and 15,000 kg ha^(-1),which in turn promoted aggregate formation and stability,and ultimately amended pore structure.The pore size>100μm,porosity(>2μm),and morphological characteristics(anisotropy,circularity,connectivity and fractal dimension)significantly increased,but the total number of pores significantly decreased(P<0.05).Our results indicated that the amendment of the pore morphology and size distribution of soil aggregates was primarily controlled by the higher contents of C and N in the density fractions of aggregates,rather than in the aggregate sizes.Furthermore,this pore network reconfiguration favored the storage of C and N simultaneously.The findings of this study offer valuable new insights into the relationships between C and N storage and the pore characteristics in soil aggregates under straw return.

关 键 词：aggregate pore structure black soil density fractions water-stable aggregates X-ray micro-computed tomography 

分 类 号：S153.3[农业科学—土壤学] S153.2[农业科学—农业基础科学]