土壤有机质和全氮水平与土壤碳排放的相关性及估算模型

Correlation Between Soil Organic Matter,Total Nitrogen and Soil Carbon Emissions and Their Estimation Model

【目的】探明土壤有机质和全氮对土壤碳排放的影响及分析估算碳排放模型的可行性,为土壤固碳减排和创建简单易行、普适性高的土壤碳排放评估方法提供参考。【方法】采用田间试验和模型拟合相结合的方法,以土壤有机质9 g/kg、全氮0.4 g/kg(5~6级肥力)为CK,研究不同土壤肥力水平有机质和全氮含量[OL:有机质41.0 g/kg、全氮2.1 g/kg(1级肥力);SL:有机质31.0 g/kg、全氮1.6 g/kg(2级肥力);TL:有机质21.0 g/kg、全氮1.1 g/kg(3级肥力);FOL:有机质11.0 g/kg、全氮0.8 g/kg(4级肥力);FIL:有机质9.0 g/kg、全氮0.6 g/kg(5级肥力)]对土壤碳排放的影响,并分析以有机质和全氮含量为因子拟合模型用于土壤碳排放量估算的准确性和适用性。【结果】土壤肥力水平为1级时,土壤碳排放量与有机质和全氮含量呈负相关关系;土壤肥力水平为2级时,土壤碳排放量达峰值,为4320.22 kg/hm^(2),较CK显著提高88.81%;当土壤肥力水平为3~6级时,土壤碳排放量与有机质和全氮含量呈正相关关系。【结论】土壤碳排放量与有机质和全氮水平有一定的相关性,土壤有机质含量(x)、全氮含量(y)与土壤碳排放量(CE)的拟合公式为CE=2221.37-263.15x+6174.45y,该模型的预测性和准确性良好,可根据土壤肥力水平分级用于区域土壤的碳排放量估算。

【Objective】It aimed to investigate the effects of soil organic matter and total nitrogen on soil carbon emissions and to analyze the feasibility of estimating carbon emission models,which provided reference for soil carbon sequestration and emission reduction,as well as for creating a simple,easy-to-follow,and universally applicable methods for soil carbon emission assessment.【Method】Using a combination of field experiments and model fitting,the effect of different soil fertility levels[OL:organic matter at 41.0 g/kg,total nitrogen at 2.1 g/kg(level 1 fertility);SL:organic matter at 31.0 g/kg and total nitrogen at 1.6 g/kg(level 2 fertility);TL:organic matter at 21.0 g/kg and total nitrogen at 1.1 g/kg(level 3 fertility);FOL:organic matter at 11.0 g/kg and total nitrogen at 0.8 g/kg(level 4 fertility);FIL:organic matter at 9.0 g/kg and total nitrogen at 0.6 g/kg(level 5 fertility)]on soil carbon emissions were studied by using soil organic matter at 9 g/kg and total nitrogen at 0.4 g/kg(5–6 levels of fertility)as CK.Then the accuracy and applicability of fitting models with organic matter and total nitrogen content as factors for estimating soil carbon emissions were analyzed.【Result】When the soil fertility level was level 1,there were negative correlation between soil carbon emissions and organic matter together with total nitrogen content;When the soil fertility level was level 2,the soil carbon emissions reached a peak of 4320.22 kg/hm^(2),which was significantly increased by 88.81%compared to CK;When the soil fertility level were 3–6 levels,there were positive correlation between soil carbon emissions and organic matter and total nitrogen content.【Conclusion】The are correlation between soil carbon emissions and organic matter together with total nitrogen content to a certain degree.The fitting formula among soil organic matter content(x),total nitrogen content(y),and soil carbon emissions(CE)is CE=2221.37-263.15x+6174.45y.This model has good predictability and accuracy,and can be used to estimate regional soil carbon emissions based on soil fertility levels.