水稻旱作条件下土壤水分对红壤磷素的影响

Effect of Soil Moisture on Phosphorus Contents of Red Soil Under Rice Cultivation in Aerobic Soil Condition

通过温室盆栽和大田试验研究旱作水稻在施用中量磷肥条件下,土壤水分对红壤中几种磷的含量和动态的影响。研究表明:土壤水分水平和采样时间对红壤全磷、有效磷、有机磷和不同形态的无机磷含量都有极显著的影响,且相互间的交互作用明显。栽种水稻后总体来说,土壤全磷、有机磷和O-P含量均有一定的提高,有效磷和Al-P、Fe-P、Ca-P含量则下降;土壤中不同形态无机磷含量为O-P>Fe-P>Al-P>Ca-P;大田和盆栽实验相比,在4种形态的无机磷、全磷和有机磷的排列顺序、演变趋势等方面基本一致,但有效磷则出现相反的结果,同时,大田试验土壤中各种磷的含量要比盆栽试验高得多,表明盆栽条件下,由于根系密度大,使土壤磷素消耗更快。

Both field and pot experiments were carried out to study the effects of soil moisture on the changes of soil P components in a new cultivation system of rice, i.e. in aerobic cultivation of rice crop. The results obtained were as follows. There were significant effects of soil moisture treatment and sampling dates on total soil P, soil available P and soil organic and inorganic P, among which the significant interactions were also found. Total soil P, organic P and O-P were slightly increased after one season of rice growth in aerobic soil condition, but the reverse was true for soil available P and inorganic P (Al-P, Fe-Pand Ca-P). The contents of different inorganic P in the soil was characterized by O-P>Fe-P>Al-P >Ca-P. The changing tendency of inorganic P, total P and organic P in soil was very much similar in pot and field experiments while there was a discrepancy of soil available P of the soils in pot and field experiment. Furthermore, the contents of different P forms in the soil after field experiment were much higher than those after pot experiment, showing that the rice crop exhausted more P in pot experiment than field experiment. 