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旱地土壤水肥关系问题目前引起较多学者的重视。国外早期的研究指出:尽管根系吸收水分和养分是两个独立的过程,然而土壤水分与养分的关系却是相互制约着的。土壤中养分运输、养分的吸收以及养分的有效性因土壤水分数量而变化。尤其在降水稀少且干旱频繁的旱地土壤上,这种相互关系变得更为复杂。干旱地区肥料试验表明:不同降雨年,施肥效果因年而异,同一降雨区,施肥效果因地而异。因而施肥对水分利用效率的影响也因年因地而不同。在旱地农业中植物营养的基本问题应归结为如何在水分有限的条件下合理使用肥料,提高水分的利用效率。
The relationship between water and fertilizer in dry land now attracts more scholars’ attention. Early studies abroad pointed out: Although the root absorption of water and nutrients are two separate processes, but the relationship between soil moisture and nutrients are mutually constrained. Soil nutrient transport, nutrient uptake, and nutrient availability vary with soil moisture. This relationship has become even more complicated, especially in dry soils where rainfall is scarce and drought is frequent. Fertilizer tests in arid areas show that: in different rainfall years, the effect of fertilization varies from year to year, and in the same rainfall area, the effect of fertilization varies from place to place. The effects of fertilization on water use efficiency are also different from year to year. The basic problem of plant nutrition in dryland agriculture should be attributed to how to use fertilizer rationally under limited water conditions to improve water use efficiency.