中国农田耕层土壤有机碳现状及控制因素  

A Study on Soil Organic Carbon in Plough Layer of China's Arable Land

作　　者：李金全[1,2] 李兆磊[1,2] 江国福[1,2] 程浩[1,2] 方长明[1,2] 

机构地区：[1]复旦大学生命科学学院生物多样性科学研究所,上海200438 [2]江苏滩涂生物农业协同创新中心,盐城224002

出　　处：《复旦学报（自然科学版）》2016年第2期247-256,266,共11页Journal of Fudan University：Natural Science

摘　　要：农田土壤有机碳库是陆地生态系统中最活跃和最重要的土壤碳库之一.研究中国农田耕层土壤有机碳的空间格局及控制因素,是评价农业土壤对国家尺度碳平衡贡献的必要部分.本文通过野外实地土壤采样,整合2004—2013年间发表的有关中国农田耕层土壤有机碳的158篇研究文献的基础上,分析了中国东北、华北、华东、华南、西南和西北6个农业区耕层土壤有机碳平均含量的变化及影响因素.结果显示:以区域平均值表示的农田耕层土壤有机碳变化范围为(7.80~17.43)g·kg^(-1),有机碳含量由高到低的区域顺序为华南>西南>东北>华东>华北>西北,全国总平均含量为(14.59±6.29)g·kg^(-1).水田耕层土壤有机碳含量(18.26±7.06 g·kg^(-1))显著高于旱地土壤(11.63±5.65 g·kg^(-1))(P<0.001).旱作区作物种类对土壤有机碳含量无显著影响(P=0.37).在pH<7的土壤中,有机碳含量与pH之无显著相关性;而在pH>7的条件下,土壤有机碳含量与pH呈显著负相关关系(P<0.01).年平均气温和降雨对中国农田耕层土壤有机碳含量均有显著影响,在年平均气温MAT≤10℃的区域,土壤有机碳与年平均气温表现为显著负相关关系(P<0.01),而在MAT>10℃时表现为显著正相关关系(P<0.01);土壤有机碳含量与年平均降雨量呈显著正相关(P<0.01),年平均气温和年平均降雨量无交互作用(P=0.63).Soil organic carbon in arable soil is the most active soil carbon pool in terrestrial ecosystems. It is cr tical to understand the temp-spatial patterns and controlling factors of soil organic carbon in plough layer of arable soil in China. In this study, soil organic carbon （SOC） content in plough layer （0--20 cm） of china＇s arable soil in different regions（Northeast, North, East, South, Southwest and Northwest of China）was analyzed. SOC data were collected through field soil sampling and from literature published during the period of 2004 to 2013. The results showed that SOC content of topsoil in China＇s arable land varied from 7.80 to 17.43 g.kg-1 , with a mean value of （14.59 ±6.29） g. kg-1. SOC of plough layer in different agricultural regions were in the order South〉 Southwest,Northeast〈East〉North）Northwest. SOC in paddy field, （18.26±7.06） g.kg-1 , was significantly higher than that in dry-farming soil（11.63 ± 5.65 g. kg-1 ）. Dry-farming crops had no significant effect on SOC content. There was no significant correlation between SOC and pH in acidic soils （pH 〈 7）, but SOC was significantly and negatively correlated soil pH value in alkaline soils. The annual mean temperature（MAT）and precipitation both had significant effects on SOC in China＇s arabsoils. In regions of MAT≤ 10 ℃, SOC was significantly and negatively correlated to MAT. On the contrary SOC in plough layer was significantly and positively correlated to MAT in regions where MAT 〉 10 ℃. Across all agricultural regions, SOC was significantly and positively correlated with the mean annual precipitation.

关 键 词：农田生态系统 土壤有机碳 耕层 中国 

分 类 号：Q148[生物学—生态学]