不同年限弃耕水田土壤养分及碳储量变化的研究

Study on the Changes of Soil Nutrient and Carbon Stock in Abandoned Paddy Fields

通过采集不同年限弃耕水田与2个天然湿地的土壤,对不同年限弃耕水田土壤理化性质以及不同土层深度土壤有机碳储量的变化进行了分析研究。结果表明:(1)随着弃耕年限增大,垂直剖面的土壤容重和孔隙度的变异系数变大;(2)除了速效氮,其他土壤养分含量大致随土层深度的增加而减小;(3)土壤有机质、全氮和速效氮含量是先增大后减小,全磷含量是先增大后减小再增大;(4)20~40cm土层深度土壤有机碳储量占0~40cm深度的50%以上,10~15a弃耕水田20~40cm占比最大,达其60%以上。

In this study,we collected the soil from abandoned paddy fields and two wetlands,to analyze physical and chemical properties of soil,and the change of soil organic carbon storage in different soil depths.The results showed that：（1）With the increase of abandoned years,the coefficient of variation of soil bulk density and porosity in the vertical section became larger.（2）In addition to available nitrogen,other soil nutrient content decreases with increasing soil depth.（3）The contents of soil organic matter,total nitrogen and available nitrogen increased first and then decreased,and the total phosphorus content first increased then decreased and then increased.（4）The depth of soil organic carbon in 20-40 cm accounted for more than 50% of the depth of 0-40 cm,and the proportion of 20-40 cm accounted for the largest in 10-15 a abandoned paddy field,accounting for more than 60%.