利用meta分析研究水田土地利用方式下化肥对土壤有机碳含量的影响。结果显示：长期施用化肥处理的表层水稻土土壤有机碳含量较不施肥处理显著提高1.000.23 g kg~（-1），是不施肥处理的1.06倍1.01倍。分析认为施肥处理下，较高的根系生物量导致较高的碳输入水平，另外相对充足的养分供应提高土壤固碳效率，这是施肥处理下土壤具有较高有机碳含量的两个原因。但不同轮作制度下，化肥对有机碳含量提升作用有差异：稻-稻-旱轮作制下化肥的作用不显著，而稻-旱轮作与稻-稻轮作制度下化肥对有机碳含量的提升作用显著。方差分析发现相同施肥措施下，稻-稻-旱轮作体系下土壤有机碳含量在三种轮作制度中最高，而稻-旱轮作与稻-稻轮作没有显著差异。尽管施用化肥能增加土壤有机碳含量，但评价施用化肥对温室效应的影响还需要综合考虑化肥生产、运输与施用过程中的温室气体排放三要素。
英文摘要:
Effect of long-term application of chemical fertilizers on content of organic carbon (SOC) in paddy soil was analyzed with the meta-analysis method. Results show that the practice increased SOC content in the top soil layer of the paddy field by 1.00 0.23 g kg~(-1), or by 1.06 1.01 times as compared with control (CK). Analysis reveals that fertilization increased root biomass of the crop and hence input of carbon, and relatively sufficient nutrient supply from chemical fertilizer led to higher soil carbon sequestration efficiency. These two are believed to be the causes of higher SOC content in paddy field under long-term chemical fertilization. However, the effect of chemical fertilization varied with the rotation system. It was not so significant under the rotation system of rice-rice-upland crop, but was under the systems of rice-upland crop and rice-rice. One-way ANOVA analysis shows that in paddy fields, the same in fertilization, SOC content was the highest in the field under the system of rice-rice-upland crop, and little difference in SOC content was found between the other two rotation systems. Although application of chemical fertilizer significantly increases SOC content, it is essential to take into account comprehensively the emissions of greenhouse gases from the processes of manufacturing and transporting chemical fertilizers, besides the contribution of fertilization to global warming.