山东石灰性潮土、褐土无机磷的形态、转化和有效性

应用蒋柏藩、顾益初提出的“石灰性土壤无机磷分级方法”研究了山东省石灰性潮土、褐土、砂姜黑土的无机磷组成、转化和对作物的有效性。结果表明,石灰性土壤无机磷中以Ca10-P占绝对优势,约占无机磷总量的54.52％,其次为O-P,占21.55％,Al-P、Fe-P,Ca8-P分别占5～10％,Ca2-P只有1.08％;在土壤剖面中各级无机磷皆随剖面深度增加而减少;水溶性磷肥施入土壤后,在作物一个生长季节内主要转化成Ca8-P,占全部转化量的50～70％,其次是Ca2-P,占10～30％,Al-P占11～13％,Fe-P很少,占5％左右;在各级无机磷中对作物有效性顺序是Ca2-P>Al-P、Fe-P>Ca8-P>O-P、Ca10-P。

Forms, Transformation and Bioavailability of Inorganic Phosphorus in Calcareous Chao Soil and Cinnamon of Shandong

We investigated fractions, transformation and bioavailability of inorganic phosphorus (P) in calcareous soils, alluvial soil, cinnamon soil and black clay soil in Shandong province. Results indicated that the fraction of Ca10 - P accounts for 54.52% of the total inorganic phosphorus, followed by O - P 21. 55%, Al - P(5 - 10% ), Fe - P(5 -10% ) and Ca8 - P(1.08% ) respectively. Each fraction of inorganic phosphorus appears to decrease with soil depth. When soluble phosphorus was added to the soil, it was mainly transformed into Ca8 - P, constituting up to 50 - 70 % during one cropping period. In contrast, only 10 - 30%, 11 - 13 % and 5 % were converted into Ca2 - P, Al - P and Fe - P forms respectively. Results indicated that the various fractions of inorganic phosphorus showed different bioavailability with an order of Ca2 - P>Al - P, Fe - P>Ca8 - P>O - P, Ca10 - P.