有机物料投入对中国农田土壤有机碳含量影响的整合分析

Effects of organic materials input on soil organic carbon in China based on Meta-analysis

土壤有机碳含量是土壤肥力的重要标志,有机物料添加对于提升土壤有机碳含量具有重要作用。但是不同自然条件和农艺措施下有机物料添加对土壤有机碳含量的系统性影响尚不明确。研究搜集了国内外公开发表的相关文献数据,并建立了有机物料投入下农田土壤有机碳变化的数据库。运用整合(Meta)分析方法定量分析有机物料投入对表层土壤有机碳含量影响的综合效应,进而量化分析自然因素和人为因素对表层土壤有机碳含量的影响。研究结果表明,与不施肥相比,施用有机物料可以显著增加表层土壤有机碳41.9%。不同区域、土壤质地、土壤pH、初始有机碳含量、碳投入量、有机物料类型、施用有机物料时间和种植制度条件下,施用有机物料对表层土壤有机碳含量的影响均存在显著差异。在华北地区有机碳的增加率最大(58.3%),且显著高于东北地区(31.5%)和西北地区(32.1%);黏土(48.2%)和壤土(41.7%)有机碳增加率均显著高于砂土(25.0%);碱性土壤(50.9%)有机碳增加率显著高于酸性土壤(29.4%);土壤初始有机碳含量<6 g/kg的土壤有机碳增加率(90.3%)显著高于土壤初始有机碳含量6~12和>12 g/kg的土壤有机碳增加率(37.5%和38.2%);累计碳投入量>100 Mg/hm^(2)时土壤有机碳增加率(87.8%)显著大于累计碳投入量<50和50~100 Mg/hm^(2)(15.6%和36.7%);施用粪肥土壤有机碳增加率(46.5%)显著高于施用秸秆(33.6%);施用有机物料时间<10年的土壤有机碳增加率(16.6%)显著低于施用有机物料10~20和>20年(47.0%和52.2%);种植制度为一年两熟时施用有机物料土壤有机碳增加率(47.8%)显著高于种植制度为一年一熟(32.4%)。综上,施用有机物料对提升土壤有机碳含量具有重要意义。提升土壤有机碳含量需要考虑不同区域特点,加大单季有机物料用量,坚持长期施用有机物料以及秸秆还田和施用粪肥相结合是提升土壤有机碳的最重要措施。

Soil organic carbon content is an important index reflecting soil fertility,and the addition of organic materials plays an important role in improving soil organic carbon content.However,the systematic effect of organic material addition on soil organic carbon content under different natural conditions and agronomic practices is still unclear.By using the data collected from published literatures,a data set with the same soil organic carbon fractionation method from independent research was built up.Meta-analysis method was used to quantify the effect degree of applying organic materials on soil organic carbon content,and then the effects of natural factors and human factors on soil organic carbon content were quantitatively analyzed.The result showed that,compared with no fertilizer treatment,organic materials application significantly increased soil organic carbon content by 41.9%.The effects of applying organic materials on soil organic carbon content under different experiment region,soil texture,soil pH,initial soil organic carbon content,organic materials type,experiment duration and planting system were significantly different.The increase rate of soil organic carbon in North China(58.3%)was the highest and significantly higher than that in Northeast China(31.5%)and Northwest China(32.1%).The increase rate of organic carbon in clay and loam soil(48.2%and 41.7%)was significantly higher than that in sandy soil(25.0%),and that in acid soil(29.4%)was significantly lower than that in alkaline soil(50.9%).The increase rate of soil organic carbon content(90.3%)with low initial soil organic carbon content(<6 g/kg)was significantly higher than those(37.7%and 38.2%)with high initial soil organic carbon content(6-12 g/kg and>12 g/kg).The increase rate of soil organic carbon(87.8%)was significantly higher when the cumulative carbon inpute was>100 Mg/hm^(2) than those(15.6%and 36.7%)when the cumulative carbon input was<50 and 50-100 Mg/hm^(2).The increase rate of soil organic carbon by applying manure(46.5%)was significantly higher than that by applying straw(33.6%).The increase rate of soil organic carbon content(16.6%)in short time(<10 years)was significantly lower than that(47.0%and 52.2%)in long time(10-20 years and>20 years).The increase rate of soil organic carbon(47.8%)was significantly higher in double cropping system than that(32.4%)in single cropping system.Application of organic materials is of great significance to increase soil organic carbon content.From these results we concluded that to improve soil organic carbon content,soil characteristics of different regions should be considered.The most important measures to improve soil organic carbon content are to increase the amounts of organic materials per season,adhere to long-term application of organic materials and combine straw returning with manure application.