长期施肥下红壤旱地土壤CO_2排放及碳平衡特征  

Characteristics of soil CO_2 emission and carbon balance under long-term fertilization in red soil

作　　者：黄晶[1,2] 李冬初[1,2] 刘淑军[1,2] 刘宏斌[1] 王伯仁[1,2] 

机构地区：[1]中国农业科学院农业资源与农业区划研究所,北京100081 [2]祁阳农田生态系统国家野外试验站,湖南祁阳426182

出　　处：《植物营养与肥料学报》2012年第3期602-610,共9页Journal of Plant Nutrition and Fertilizers

基　　金："973"项目(2005CB121101);2011农业生态环境保护项目;中央级公益性科研院所基本科研业务费专项资金(2012-12)资助

摘　　要：在国家肥力网红壤旱地长期定位试验地上,采用静态箱/气相色谱法测定土壤CO2排放速率,同时利用根去除法区分根系对土壤呼吸的贡献,通过计算净生态系统生产力(NEP),判断长期不同施肥下红壤旱地农田碳汇强度。结果表明,小麦、玉米生长季各处理的土壤和土体呼吸速率随着作物生长、温度升高均呈现明显的季节变化;玉米生长季土壤和土体累积呼吸量大于小麦生长季,小麦、玉米生长季均以有机无机肥配施处理(NPKM)土壤和土体呼吸累积呼吸量最大,且显著高于其它处理(P<0.05),NP和NPK处理次之,CK和NK处理最小(P<0.05);小麦、玉米生长季各处理根际呼吸占土壤呼吸的比例分别为7.6%～17.4%、4.7%～16.6%,均以NPKM处理根际呼吸贡献率最大;小麦季NPKM处理、玉米季CK和NPKM处理的NEP值为负,是大气CO2的"汇",且NPKM处理的净初级生产力与土壤呼吸的比值(NPP/Rs)最大,其它处理NEP值均为正,是大气CO2的"源"。NPKM处理比其它处理具有较强的碳"汇"功能,是红壤旱地比较合理的施肥措施。Diurnal variation of soil respiration affected by fertilization was investigated with the static dark chamber method and gas chromatograph technique at the long-term experiment in red soil, and the contribution of root respiration was detected by root exclusion method. Net ecosystem productirity（NEP） was calculated for estimating carbon sequestration intensity. The results show that there are significant seasonal variations of the soil respiration rate and bulk respiration rate as the crop growth and temperature raise in wheat and maize growth seasons in all treatments. The accumulation amount of soil respiration and bulk respiration in the maize growth season is greater than that in the wheat growth season. The accumulation amount of soil respiration and bulk respiration of the NPKMtreatment is the largest in the wheat and maize growth seasons, and is higher than those of the other treatments significantly （P 〈 0. 05）. The accumulation amounts of soil respiration and bulk respiration of the NP and NPK treatments are the second, and those of the CK and NK treatments are minimum. The mean ratios of root respiration to total soil respiration in the wheat growth seasons and maize growth seasons are 7.6%-17.4% and 4.7%- 16.6%, and the contribution ratio of rhizospheric respiration of the NPKM treatment is largest in all treatments. Soils are sinks of atmospheric CO2 under the NPKM and CK treatments. Compared to other treatments, inorganic fertilizer combination （NPKM） has a stronger carbon sink function, therefore the NPKM is reasonable fertilization in red soil.

关 键 词：长期施肥 红壤 土壤呼吸 土体呼吸 碳平衡 

分 类 号：S154[农业科学—土壤学]