农田土壤碳氮及其与气象因子的关系

为揭示土壤碳氮受外界环境因子的影响,基于辽宁省51个农业气象站的代表性,分析了土壤有机碳和全氮的剖面分布及其与气象因子、地理因子的关系。结果表明,土壤表层（0~20 cm）有机碳和全氮含量总体高于土壤下层（20~40 cm）;不同土层土壤有机碳和全氮受年降水量、年平均气温的影响程度不同。土壤表层有机碳和全氮受年降水量、年平均气温的显著或极显著影响（P〈0.05,P〈0.01）;土壤下层有机碳和全氮均与年平均气温呈显著负相关（P〈0.01）,而与年降水量不成显著相关。经度与土壤表层有机碳和土壤下层全氮呈显著正相关（P〈0.05）,而纬度和海拔不影响土壤有机碳和全氮。不同土层有机碳、全氮与气象因子的回归方程为农田生态系统的碳收支评估及养分循环提供基础资料。

Soil Carbon,Nitrogen of the Farmland and Their Relationships with Climatic Factors

The cycles of soil carbon and nitrogen are the basic ecological processes in the farmland ecosystem.In addition to the influence of farm management strategy,the contents of soil carbon and nitrogen are also affected by the external environment factors.In this paper,the profile distribution of soil carbon,and nitrogen and their responses to the climatic and geographical factors were analyzed using data from 51 agriculture weather stations in the Liaoning Province.The results showed that the contents of soil organic carbon and total nitrogen were high-er in the soil surface（0~20 cm）than those in the lowe（r20~40 cm）.It was different for effects of precipitation and temperature on soil organ-ic carbon and total nitrogen in different soil layers.Soil organic carbon and total nitrogen were significantly influenced by annual total precip-itation and annual mean temperature in the soil surface（P0.05,P0.01）;and were markedly negatively correlated with annual mean temperature（P0.01）,but not with precipitation in the lower soil layer.Longitude exhibited a positive correlation with soil organic carbon in the soil surface and soil total nitrogen in the lower soil layer（P0.05）,while latitude and elevation not with soil organic carbon and total nitrogen.The regression equations of soil organic carbon and soil total nitrogen with precipitation and temperature were also established,which provides the basic data to evaluate the carbon budget and nutrient and biogeochemical cycles of farmland ecosystem.