黑土坡耕地土壤有机质与生产力的空间关系

目的]从田块尺度上揭示黑土坡耕地生产力与土壤有机质和全氮的空间关系,为坡耕地水土流失的治理和农业生产提供参考。方法]利用经典统计学和地统计学的方法对典型黑土区坡耕地大豆产量与土壤有机质、全氮、海拔高度的空间关系进行分析。结果]坡耕地大豆产量、土壤有机质和全氮含量存在较大变异,分别为0.05~0.26g/kg,19.27~52.64g/kg和0.95~2.38g/kg,但大豆产量与土壤有机质和全氮之间不存在显著的空间相关关系,与海拔高度之间存在负相关,但不显著。土壤有机质和土壤全氮之间存在极显著相关关系。结论]坡耕地生产力受地形、地下水位、成土过程等结构性因子的影响约占2/3,受人类耕作、施肥、种植作物的影响只占1/3。水土流失是造成黑土农田生产力降低的主要因素。

Spatial Correlation of Soil Organic Matter Content and Productivity in a Black Soil Sloping Farmland

Objective] A case research in a black soil sloping farmland was conducted to illustrate the spatial correlations among productivity, organic matter and total nitrogen content, in order to provide some hints for controlling of soil and water loss and improving of agricultural production in simliar slope farmlands. Methods] Spatial correlations among productivity, organic matter and total nitrogen content were analyzed by classical statistics and geostatistics methods. Results] There was no significant correlations of soil productivity with organic matter content and total nitrogen content. A insignificant negative correlation(p<0.05) between soil productivity and altitude was found. There existed a significant correlation between soil organic matter content and total nitrogen content(p<0.01). Conclusion] The productivity of the sloping farmland was greatly affected by soil structure factors, such as terrain, groundwater level and soil forming process; about sixty-seven percent of the variance of productivity can be explained by them.Other thirty-three percent variance was affected by cultivation, fertilizer application and planting. Soil erosion was thought to be the dominated process that lead to the reduction of the black soil productivity on sloping farmland.