农业环境科学学报Issue(4)：753-760,8.DOI:10.11654/jaes.2015.04.021
长期施肥下水稻土有机碳固持形态与特征
Characteristics of Organic Carbon Stabilization in Paddy Soil Under Long-term Different Fertilization
摘要
Abstract
Understanding the mechanisms of soil organic carbon(SOC)stabilization would help improve soil carbon sequestration in paddy soil. In this paper, we obtained paddy soils from a 30 year experimental field under five different fertilization, including no fertilizer(con-trol), mineral nitrogen(N)-phosphorus(P)-potassium(K)fertilizers(NPK), 70%mineral N+30%organic N plus PK(NPKM7/3), 50%mineral N+50%organic N plus PK(NPKM5/5), and 30%mineral N+70%organic N plus PK(NPKM3/7). Organic N was provided from green manure and pig manure. The soils were subjected to separating unprotected, and physically, chemically, bio-chemically, physical-chemically, and physical-biochemically protected SOC fractions by a physical-chemical combined fractionation method. Except the unpro-tected light fraction and the occluded silt and clay-sized fraction, the mass proportion of all other SOC factions was significantly different be-tween the treatments. Compared with non-fertilization(CK)treatment, chemical fertilizers mixed with organic manure(NPKM7/3、NPKM5/5 and NPKM3/7)significantly increased the content of total SOC(19.1~25.0 g·kg-1), unprotected coarse particulate organic carbon(cPOM) (8.41~12.7 g·kg-1), and physically protected aggregate(μagg)organic carbon(6.41~6.62 g·kg-1)in red paddy soil(P﹤0.05). There were no significant differences for the chemically, biochemically, physical-chemically and physical-biochemically protected fractions between the five treatments. These results indicated that the unprotected cPOM and the physically protected μagg fractions were the most sensitive ones in long-term fertilization. There was a linear positive correlation between total SOC and tcPOM, physically protected μagg, and oc-cluded POM inside theμagg(iPOM)fraction(P﹤0.05), and their response efficiency to total SOC accumulation(the slope of the regression) was 0.5, 0.12, and 0.12 respectively. However, the response efficiency of non-hydrolysis clay and physic-chemically protected silt fraction to total SOC accumulation was only 0.02 to 0.03, even though they had significant responses. There was no significant relationship of the rest fractions with total SOC. Under the present cropping and management practices, cPOM and micro-aggregates were the main stabilization mechanisms for soil carbon sequestration. Soil physically, chemically, biological-chemically and physical-biochemically protected SOC fractions might have reached the maximum capacity in this paddy soil.关键词
有机碳/组分/稳定机制/水稻土/土壤碳固定Key words
soil organic carbon/fractionation/stabilization mechanism/paddy soil/carbon sequestration分类
农业科技引用本文复制引用
徐香茹,蔡岸冬,徐明岗,汪景宽,张文菊..长期施肥下水稻土有机碳固持形态与特征[J].农业环境科学学报,2015,(4):753-760,8.基金项目
国家自然科学基金面上项目（41371247）；中央级公益性科研院所专项资金资助项目 （）
