氮、磷营养过量对土壤养分及黄瓜营养吸收的影响初探

Preliminary Study on the Effects of Excess Soil N and P on Soil Nutrient Elements and Cucumber Nutrient Absorption

采用土壤培养试验研究土壤氮、磷单个养分分别过量的条件下,土壤养分状况的改变以及黄瓜植株养分吸收的变化。结果表明,土壤氮素过剩使土壤交换性K、Ca、Mg含量增加6%左右,水溶性K、Ca、Mg含量成倍增加,易于形成土壤盐类障碍。土壤磷素过剩反而导致土壤交换性K、Ca含量下降,尤其是以交换性Ca下降为多,水溶性K、Ca、Mg含量减少50%左右。土壤氮素过剩抑制了黄瓜磷的吸收;相反,土壤磷素过剩时,氮吸收受抑。土壤氮、磷营养过剩在高量下均对黄瓜植株K、Ca、Mg的吸收表现出抑制作用。

Excess soil N and P are very common in modern greenhouse agriculture system. This results in low fertilizer efficiency and environmental pollution. Effects of excess soil N and P on the cucumber yield, nutrient absorption and soil nutrient concentration were investigated by using pot experiments. The results showed that excess soil N did not change soil Olsen-P content significantly; however, the concentration of exchangeable K, Ca, Mg increased 6% and water soluble K, Ca, Mg content increased exponentially. Excess P did not change soil inorganic N concentration; however, exchangeable K and Ca content decreased, especially exchangeable Ca. The concentration of water soluble K, Ca, Mg content reduced about 50%. At excess N condition, the cucumber appears normal, however, yield and dry weight decreased, the concentration of K, Ca, Mg in the plant increased. At excess P of the studied level, cucumber yield and dry weight even increased; P absorption was enhanced, but N absorption was inhibited. High content of N or P in soil all reduced the absorption of K, Ca, Mg by cucumber.