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根据同位素示踪和化学分析得知:小麦全生育期所需养分大部分来自土壤,少部分来于肥料;而肥料主要是供给作物前期需要。如果增施肥料,改变作物根系范围内的肥料与土壤有效养分的比例关系,则作物从肥料中吸收的养分比例就会相应增加。土壤中的各种养分都是通过作物根际吸收的。根据国外试验,小麦生育期82％的氮是靠作物水分蒸腾作用引起土壤水分、养分向根表移动吸收的。磷的56％、钾的63％是在作物根系吸收养分过程中靠根表养分浓度差异扩散到根表吸收的,只有20％的磷和36％的钾是靠
According to isotope tracing and chemical analysis, most of the nutrients needed during the whole growth period of wheat come from the soil, and a small part comes from fertilizers. The fertilizer is mainly needed to supply crops in the early stage. If fertilizers are applied to alter the ratio of fertilizers to soil available nutrients within the crop root system, the proportion of nutrients that the crop absorbs from fertilizers will increase accordingly. Various nutrients in the soil are absorbed through the crop rhizosphere. According to foreign experiments, 82% of the nitrogen during the growing period of wheat is caused by soil moisture and nutrient transfer to the root table by the transpiration of crops. 56% of phosphorus and 63% of potassium are absorbed by the difference of root nutrient concentration in the roots during nutrient uptake, and only 20% of phosphorus and 36% of potassium are absorbed