摘要
采用1 4 C同位素示踪恒温密闭培养法 ,研究了秸秆和化肥配合施用体系中 ,无机氮对1 4 C秸秆碳矿化的影响 ,培养期一年。结果表明 ,在非石灰性土壤中 ,无机氮的施用促进了1 4 C秸秆碳的矿化 ,相对增加了土壤固有碳 ( 1 2 C)的固持 ,两者间的互补显示无机氮对土壤总碳矿化的影响不大 ;淹水土壤中的1 4 C秸秆碳年矿化率比旱地高 ,发现无机氮对1 4 C秸秆碳年矿化率的增加不论在旱地或水田状况是近似的。在石灰性土壤中 ,无机氮对1 4 C秸秆碳、土壤固有碳的矿化均起到抑制作用 ,没有发现无机氮对有机碳矿化的促进。对有机肥和无机肥配合施用体系中 ,化学氮肥对土壤有机碳转化影响 ,以及化学氮肥在土壤有机碳内循环中的作用功能等 。
The 14 C tracing technology and isothermally sealed incubation method were used to study effect of inorganic N on mineralization of straw 14 C in a combined fertilization system of mineral N and plant residue for one year. Results indicated that in non calcareous soil, application of inorganic N accelerated mineralization of straw C, but relatively strengthened the immobilization process of indigenous soil C. It might be likely that the increase in the amount of straw C mineralized compensated for the increase in the amount of indigenous C immobilized, hence, inorganic N might have only little effect on mineralization of total organic C in soil. The annual mineralization rate of straw 14 C was greater in submerged soil than in upland soils, and the increase in the annual mineralization rate of straw 14 C by inorganic N was similar either in submerged soil or in upland soils. In calcareous soil, inorganic N retarded mineralization of both straw 14 C and soil native C. Promotion of organic C decomposition by inorganic N was not found in this study. This paper put forward some new views about the effect of N fertilizer on transformation of organic C, and about the role of N fertilizer in the internal cycling of soil organic C in the combined fertilization system of mineral N and plant residue.
出处
《土壤学报》
CAS
CSCD
北大核心
2001年第4期457-463,共7页
Acta Pedologica Sinica
基金
国家自然科学基金项目 (批准号 3 9770 42 9和 3 983 0 2 2 0 )
