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土壤养分是农田生态系统中物质流的重要成份,对农作物产量的形成贡献颇大,因此土壤养分状况十分引人注目。影响耕地土壤养分的因素很多,对于高原上的丘陵山地而言,以海拔高度对土壤养分的制约作用最强。因为一方面海拔高度直接影响到温度的高低和雨量的多寡,从而决定了土壤中物质的合成与分解的速率;另一方面海拔高度在一定程度上关系到人类的空间分布,涉及到土壤的物质投入与产出。通常土壤中的有机质和全氮含量随海拔的升高而递增。毕节地区土壤普查表明:海拔由1000米升至3600米,有机质则从3.13％提高
Soil nutrients is an important component of the material flow in the farmland ecosystem and contributes significantly to the formation of crop yield. Therefore, soil nutrient status is very noticeable. There are many factors affecting the soil nutrient in cultivated land. For the hilly and mountainous regions on the plateau, the limiting effect of soil nutrient on the altitude is the strongest. Because on the one hand, the altitude directly affects the level of the temperature and amount of rainfall, which determines the rate of soil synthesis and decomposition of substances; the other hand, altitude to a certain extent, relates to the spatial distribution of human beings, involving soil material Input and output. Soil organic matter and total nitrogen generally increase with altitude. Census of soil in Bijie Prefecture showed that the elevation rose from 1,000 to 3600 meters and the organic matter increased from 3.13%