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地力评价对推进农业结构调整、改良土壤和科学施肥有重要的指导作用。基于长沙县2007—2010年耕地地力调查与评价工作,本研究选取影响地力的立地条件、土壤理化性质、农田基本设施建设等方面共22项指标,以实际产量与潜在产量比作为地力高低的替代指标,采用回归树统计分析方法,对影响双季稻区水稻土地力的因素进行了分析和建模。结果表明:海拔、地形部位、田面坡度、排水能力、输水方式、土壤母质、土壤质地、耕层厚度、土壤有机质含量和有效氮含量为影响长沙县双季稻水稻土地力的主要因子,并且可用这10个因子对地力特征进行较好的模拟。回归树方法对分析大容量、多变量数据间的复杂关系具有很好的效果,可推广用于中国其他地区的地力评价工作。
Evaluation of soil fertility plays an important guiding role in promoting the adjustment of agricultural structure, soil improvement and scientific fertilization. Based on the investigation and evaluation of cultivated land productivity in Changsha County from 2007 to 2010, this study selected 22 indicators of site conditions, soil physical and chemical properties and farmland infrastructure construction that affect soil fertility, taking the ratio of actual output to potential yield as a proxy for soil fertility Index, using regression tree statistical analysis methods, the factors affecting the paddy land productivity in double cropping rice were analyzed and modeled. The results showed that elevation, topography, surface slope, drainage capacity, water conveyance, soil parent material, soil texture, topsoil thickness, soil organic matter content and available nitrogen content were the main factors affecting the paddy soil fertility of double cropping rice in Changsha County. These 10 factors can be used to better simulate the geotechnical features. The regression tree method has a good effect on the analysis of complex relationships between large-volume and multivariate data and can be used to evaluate the geotechnical assessment in other parts of China.