膨润土和磷肥对石灰性土壤无机磷形态转化及有效性的影响

对山西石灰性土壤无机磷的形态、加入外源磷后无机磷形态的转化及施加膨润土后对提高磷素的有效性进行了初步探讨 ,结果表明 :山西石灰性土壤中磷素以无机磷为主 ,而无机磷中以Ca P为主 ,Ca10 P和Ca8 P占无机磷总量的 85 % ,Ca2 P仅占 4 42 %。土壤加入外源磷后 ,Ca2 P有所增加 ,其次是Ca8 P、Ca10 P、Fe P ,Al P和O P增加很少。施加膨润土后使加入外源磷的土壤无机磷都有所增加 ,其中Ca2 P增加最明显 ,Ca8 P、Al P、Fe P增加较多 ,而Ca10 P和O P增加最少 ,说明施用膨润土是实现土壤无机磷释放的主要途径

EFFECT OF BENTONITE AND PHOSPHORUS FERTILIZER ON INORGANIC PHOSPHORUS TRANSFORMATION AND THEIR AVAILABILITIES IN CALCAREOUS SOIL

The forms of inorganic phosphorus and its form inversion after adding external phosphorus and improvement of phosphorous availability by fertilizing bentonite in Shanxi calcareous soil. were studied. The results showed that the main form of phosphorus in the soil was inorganic phosphorus,which was mainly composed of Ca-P, Ca 10-P and Ca 8-P (amount to 85%), and Ca 2-P was only 4.42%. After adding external phosphorus, Ca 2-P increased in the soil, and Ca 8-P Ca 10-P Fe-P were next to it, but Al-P and O-P increased very few. After fertilizing bentonite, inorganic phosphorus increased in the soil which had adding external phosphorus. Among all of inorganic phosphorus, Ca 2-P increased most obviously, and Ca 8-P AI-P and Fe-P next however,Ca 10-P and O-P had no significant increased , indicating that fertilizing bentonite was a principal way to release inorganic phosphorus in the soil.