Changes in soil organic carbon and aggregate stability after conversion to conservation tillage for seven years in the Huang-Huai-Hai Plain of China  

作　　者：SHU Xin ZHU An-ning ZHANG Jia-bao YANG Wen-liang XIN Xiu-li ZHANG Xian-feng 

机构地区：[1]State Experimental Station of Agro-Ecosystem in Fengqiu, State Key Laboratory of Soil and Sustainable Agriculture/Institute of Soil Science, Chinese Academy of Sciences [2]Graduate University of Chinese Academy of Sciences

出　　处：《Journal of Integrative Agriculture》2015年第6期1202-1211,共10页农业科学学报（英文版）

基　　金：financially supported by the National Basic Research Program of China(2011CB100504);the Special Fund for Agro-Scientific Research in the Public Interest,China(201203030-06);the Key Program of the Chinese Academy of Sciences(CXJQ120112)

摘　　要：Soil aggregate stability and organic carbon（OC） are regarded as effective indicators of soil structure and quality. A longterm field experiment was established in 2006 to examine the influence of tillage systems on soil aggregation and OC in a sandy loam soil in the Huang-Huai-Hai Plain of China. The study involved eight treatments： plowing every year with（TS） and without residue（T）, plowing every 2 years with（2TS） and without residue（2T）, plowing every 4 years with（4TS） and without residue（4T）, and no plowing with（NTS） and without residue（NT）. In 2013, soil samples were collected at depths of 0–5, 5–10 and 10–20 cm, and separated into three aggregate-size classes： macroaggregates（〉250 μm）, microaggregates（53–250 μm） and the silt＋clay fraction（〈53 μm） using wet sieving method. Soil parameters measured were water-stable aggregates, geometric mean diameter（GMD）, mean weight diameter（MWD） and OC concentrations in different aggregate-size fractions and in bulk soil. The tillage treatments significantly（P〈0.05） influenced soil aggregate stability and OC distribution. Higher MWD and GMD were observed in 2TS, 4TS and NTS as compared to T. With increasing soil depth, the amount of macroaggregates and MWD and GMD values were increased, while the proportions of microaggregates and the silt＋clay fraction were declined. The OC concentrations in different aggregate fractions at all soil depths followed the order of macroaggregates〉microaggregates〉silt＋clay fraction. In the 0–5 cm soil layer, concentrations of macroaggregateassociated OC in 2TS, 4TS and NTS were 14, 56 and 83% higher than for T, whereas T had the greatest concentration of OC associated with the silt＋clay fraction in the 10–20 cm layer. Soil OC concentrations under 4TS and NTS were significantly higher（P〈0.05） than that of T in the 0–10 cm layer. Residue retention promoted formation of macroaggregates, increased macroaggregate-associated OC concentrations anSoil aggregate stability and organic carbon（OC） are regarded as effective indicators of soil structure and quality. A longterm field experiment was established in 2006 to examine the influence of tillage systems on soil aggregation and OC in a sandy loam soil in the Huang-Huai-Hai Plain of China. The study involved eight treatments： plowing every year with（TS） and without residue（T）, plowing every 2 years with（2TS） and without residue（2T）, plowing every 4 years with（4TS） and without residue（4T）, and no plowing with（NTS） and without residue（NT）. In 2013, soil samples were collected at depths of 0–5, 5–10 and 10–20 cm, and separated into three aggregate-size classes： macroaggregates（〉250 μm）, microaggregates（53–250 μm） and the silt＋clay fraction（〈53 μm） using wet sieving method. Soil parameters measured were water-stable aggregates, geometric mean diameter（GMD）, mean weight diameter（MWD） and OC concentrations in different aggregate-size fractions and in bulk soil. The tillage treatments significantly（P〈0.05） influenced soil aggregate stability and OC distribution. Higher MWD and GMD were observed in 2TS, 4TS and NTS as compared to T. With increasing soil depth, the amount of macroaggregates and MWD and GMD values were increased, while the proportions of microaggregates and the silt＋clay fraction were declined. The OC concentrations in different aggregate fractions at all soil depths followed the order of macroaggregates〉microaggregates〉silt＋clay fraction. In the 0–5 cm soil layer, concentrations of macroaggregateassociated OC in 2TS, 4TS and NTS were 14, 56 and 83% higher than for T, whereas T had the greatest concentration of OC associated with the silt＋clay fraction in the 10–20 cm layer. Soil OC concentrations under 4TS and NTS were significantly higher（P〈0.05） than that of T in the 0–10 cm layer. Residue retention promoted formation of macroaggregates, increased macroaggregate-associated OC concentrations an

关 键 词：aggregate conservation residue sequestration aggregation depths proportions declined wheat concluded 

分 类 号：S345[农业科学—作物栽培与耕作技术]