栗钙土中磷肥转化及效应的研究

TRANSFORMATION OF APPLIED PHOSPHORUS AND YIELD RESPONSE OF NAKED OAT TO P FERTILIZER IN CHESTNUT SOIL

采用石灰性土壤无机磷的分级方法,研究了磷肥在栗钙土中的转化以及包被物对土壤中磷肥转化的影响和莜麦的磷肥效应。研究结果表明,在不种作物的情况下,磷肥施入土壤后很快转化为Ca_2-P、Ca_8-P、Al-P、Fe-P等形态,随施肥时间的延长,Ca_2-P呈减少趋势,其它形态的无机磷则逐渐增加;在种植莜麦的情况下,莜麦对磷肥的吸收利用率为31.1％,土壤残留为68.9％,残留磷中各形态无机磷占施入磷的比率:28.9％为Ca_2-P,11.0％为Ca8-P,10.3％为Al-P,5.5％为Fe-P,9.5％为O-P,3.7％为Ca_(10)-P;包被磷肥较未包被磷肥减少了土壤中Ca_2-P向Ca_8-P转化,增加了施入磷向Al-P的转化而减少了向Fe-P、O-P的转化,磷肥的利用率提高2.9个百分点。施用磷肥莜麦增产178％。

Transformaion of applied phosphorus and yield response of naked oat to P fertilizer were studied in chestnut soil, using fractionation scheme of inorganic P in calcareous soils. The results obtained showed that applied P was transformated into Ca2-P, Ca8-P, Al-P, Fe-P after fertilization during incubation for short time. The content of Ca2-P was decreased repidly in the following days but that of Ca8-P, Al-P, Fe-P were increased. 31. 1% of applied P was absorbed by naked oat and 68.9% was resided in the soil when P fertilizer was applied in the soil with naked oats. In the residual P Ca2-P accounted for 28.9% of total applied P, Ca8-P 11.0%. Al-P 10.3%, Fe-P 5.5%, O-P 9.5% and Ca10-P 3.7%. The coated P decreased the transformation of Ca 2 - P to Ca8 - P increased transformation rate of applied P into Al-P but transformation into Fe-P, O-P were decreased. P use efficiency was incredsed by 2.9 percentage point as compared with uncoated P. P fertilizer increased yield of naked oat by 178% in the soil with low levels of available phosphorus.