不同用量有机肥对陇东旱塬黑垆土磷素形态转化及有效性的影响

以覆盖黑垆土土壤为材料,研究了不同用量有机肥对土壤磷素有效性及不同形态无机磷含量的影响。结果表明:在陇东旱塬黑垆土上施肥能够增加全磷、有效磷含量,有机肥增加效果更明显,且随有机肥施用量的增加而增加。无磷肥输入的氮肥处理区,活性较强的Ca_2-P、Ca_8-P、A1-P和Fe-P含量都有所降低,而较稳定态的O-P和Ca_(10)-P含量则有所提高。与CK相比,有机肥处理随有机肥用量的增加,Ca_2-P、Ca_(10)-P、A1-P含量表现为增加,而Ca_8-P、Fe-P、O-P则相反。同时Ca_2-P与有机质、有效磷显著正相关,与p H值显著负相关。因此,在本试验条件下,从有效态的Ca_2-P和难溶性的Ca_(10)-P含量变化来看,在施等量氮的基础上配施农家肥60 000 kg·hm~(-2)更有利于活化土壤磷和减缓磷吸附,从而提高磷素的有效性。

Effect of different amount organic manure on soil phosphorus forms transformation and its availability in calcic kastanozems in eastern Gansu

The effects of different amount of organic manure on soil phosphorus availability and different forms of inorganic phosphorus content were investigated in this study. The results showed that the total phosphorus and available phosphorus con-tent were increased by fertilization in calcic kastanozems soil in Eastern Gansu, especially for the manure treatments. The con-tents of high active P such as Ca2-P, Ca8-P, A1-P and P-Fe were decreased in no P fertilizer area, but the contents of O-P and Ca10-P was increased; the contents of Ca2-P, Ca10-P, A1-P were increased with the increasing amount of manure, while Ca8-P, Fe-P, O-P were on the contrary. Ca2-P was significantly positively correlated with organic matter, available P and was significantly negatively correlated with pH. Combining both the content of effective form of Ca2-P and the undissolved Ca10-P, it was suggested that the application of 60000 kg·hm-2 manure was the most effective to active soil P, reduce P adsorption, and improve the phosphorus availability.