水分对旱稻土壤及植株中主要营养元素含量的影响

在防雨棚池栽条件下研究了不同水分处理下土壤矿质元素的释放及旱稻植株对矿质元素的吸收利用特点。结果表明：土壤水分对土壤N、P、K含量及植株养分吸收存在明显影响。随着土壤水分含量的提高,土壤硝态氪含量显著下降,氨态氪含量显著上升;磷素在低水分处理下先升高后基本保持较高水平,而在高水分处理下有一个升降升的变化过程;钾素在65％、100％水分处理下在分蘖中后期显著大于其它水分处理,而在分蘖前期各水分处理都有一个先降后升的变化趋势。在植株对矿质元素的吸收上,100％水分处理下植株体内的全氮含量一直呈下降趋势,65％、75％处理下磷素变化呈“U”型,其余各处理下植株体内的N、P、K含量都呈W型变化。随土壤含水量的增加,旱稻植株对N、P、K的吸收总量均增加。

Effects of moisture on content of major nutrients in soil and upland rice plants

The experiment was carried out with pond culture under rain-proof shelter condition to investigate the release of mineral elements in soil and the absorption of mineral elements by upland rice plants.The results indicated that soil moisture influenced remarkably N,P and K content in soil and nutrients absorption by plants.With the increase of soil moisture,the NO^-₃-N content in soil was markedly decreased and the NH4+-N content was increased;The content of P changed with low-high-high curve under low soil moisture,and with high-low-high curve under high soil moisture;The content of K in the early tillering stage changed with low-high tendency under different soil moisture treatments,and its content in 65% and 100% treatments was higher than others during the mid and late tillering stage.As for the nutrients absorption by plants,the N content in upland rice was decreased continuously under 100% soil moisture,the P content assumed the "U" curve under 65% and 75% treatments,while the N,P and K content in upland rice assumed the "W" curve under other moisture treatments.With the increase of soil moisture,the total absorption quantity of N,P and K in upland rice was all added.