湘西与湘中耕地的土壤养分限制因子差异分析

Study on Soil Nutrient Limiting factors in the Plantation of Xiangxi and Xiangzhong Areas,Hunan Province

采用土壤养分测试、吸附试验和温网室生物盆栽试验相结合的诊断程序,以高粱为指示作物,对湘西与湘中耕地土壤的养分限制因子进行了系统诊断。结果表明:湘中耕地土壤的养分限制因子仅为N,生物盆栽试验中缺N使高粱生物量减少81%;而湘西耕地土壤的养分限制因子相对较多,其中N是第1养分限制因子,P是第2养分限制因子,S是第3养分限制因子,缺N、缺P、缺S分别使高粱生物量平均减少85%、45%、32%。

The limiting factors of soil nutrient were identified by systematic application of indicator plant（grain sorghum） and diagnostic soil analysis（soil adsorption trial and pot experiment） in the plantation of Xiangzhong and Xiangxi areas,Hunan province.The results showed that there were more nutrient limiting factors in the soils of Xiangxi areas than Xiangzhong areas.N was the only soil nutrient limiting factor in the plantation of Xiangzhong areas,while N,P,and S was the first,second and third soil nutrient limiting factor in the planteation of Xiangxi areas,respectively.Compared with OPT treatment,biomass of grain sorghum plant grown under N-lacked treatment decreased by 81% in plantation of Xiangzhong areas,while it decreased by 85%,45% and 32% under the N-,P-and S-lacked tteatment in the plantation of Xiangxi areas,respectively.