松嫩平原玉米带土壤碳氮储量的空间特征

利用第二次全国和县级土壤普查的382个典型土壤剖面资料和1∶50万数字化土壤图建立土壤剖面空间数据库,利用土壤类型法估算松嫩平原玉米带土壤碳、氮储量,分析土壤有机碳、氮密度的空间分布特征,探讨土壤有机碳、氮密度与土壤类型和土地利用类型之间的关系.结果表明:松嫩平原玉米带土壤有机碳、氮储量分别为(163.12±26.48)Tg和(9.53±1.75)Tg,土壤碳、氮储量主要集中在草甸土、黑钙土和黑土等土类中.土壤有机碳、氮密度分别为5.51～25.25和0.37～0.80kg·m-2,土壤C/N值大致在7.90～12.67.土壤有机碳、氮密度的空间分布均表现为东部和北部高、西部低.在不同土地利用类型中,旱田土壤的有机碳密度最高,为(19.07±2.44)kg·m-2;林地土壤的氮密度最高,为(0.82±0.25)kg·m-2;水田土壤的碳、氮密度均较低.

Spatial characteristics of soil organic carbon and nitrogen storages in Songnen Plain maize belt

By using the data of 382 typical soil profiles from the second soil survey at national and county levels,and in combining with 1:500000 digital soil maps,a spatial database of soil profiles was established.Based on this,the one meter depth soil organic carbon and nitrogen storage in Songnen Plain maize belt of China was estimated,with the spatial characteristics of the soil organic carbon and nitrogen densities as well as the relationships between the soil organic carbon and nitrogen densities and the soil types and land use types analyzed.The soil organic carbon and nitrogen storage in the maize belt was(163.12±26.48)Tg and(9.53 ± 1.75)Tg,respectively,mainly concentrated in meadow soil,chernozem,and black soil.The soil organic carbon and nitrogen den sities were 5.51-25.25 and 0.37-0.80 kg·m~(-2),respectively,and the C/N ratio was about 7.90-12.67.The eastern and northern parts of the belt had much higher carbon and nitrogen densities than the other parts of the belt,and upland soils had the highest organic carbon density[(19.07 ±2.44)kg·m~(-2)],forest soils had the highest nitrogen density[(0.82±0.25)kg·m~(-2)],while lowland soils had the lower organic carbon and nitrogen densities.