菜园土各形态磷库的变化及空间分布

Variation and distribution of individual phosphorus pool in the soil profile of vegetable fields

为找出菜园0～80cm土层各形态磷素的积累、分布规律,研究了菜园土各形态磷素的积累状况及在0～80cm土层的空间分布。结果表明,0～20cm菜园土的全磷和总无机磷、Olsen-P、Ca2-P、Ca8-P、Al-P、Fe-P、O-P和Ca10-P分别比相邻粮田平均增加了1 2、8 4、4 9、2 5、1 6、1 0、0 3、0 1倍,20～80cm菜园土全磷、Olsen-P、Ca2-P、Ca8-P、Al-P、Fe-P均有不同程度的积累,0～20cm、20～40cm全磷积累量分别占0～80cm积累总量的60 2%,20 8%。各形态无机磷的积累为Ca2-P,Ca8-P>Al-P>Fe-P>O-P和Ca10-P。各形态磷在0～80cm土层的分布为:20～40cm,40～60cm,60～80cm菜地全磷分别相当于0～20cm全磷量的46 1%、33 2%和25 9%,Olsen-P分别相当于38 5%、17 3%、8 8%,Ca2-P和Ca8-P分别相当于30 5%～33 6%,16 0%～17 0%和6 7%～22 3%;Al-P和Fe-P分别相当于41 5%～67 0%,26 8%～45 7%和17 4%～39 9%;O-P和Ca10-P分别相当于83 4%～92 9%,77 0%～83 7%和71 2%～81 9%。母质土壤的磷素组成和磷肥用量影响土壤各形态磷的积累量。

Variation in different phosphorus pool and distribution in the 0～80 cm profile of vegetable field was studied in this paper. The results showed that the content of total P and inorganic phosphorus, Olsen-P, Ca_2-P, Ca_8-P, Al-P, Fe-P, O-P和Ca_(10)-P in the profile of 0～20 cm vegetable field were 1.2, 8.4, 4.9, 2.5, 1.6, 1.0, 0.3, 0.1 times of that of the adjacent cultivated field, respectively. The content of total P, Olsen-P, Ca_2-P, Ca_8-P, Al-P, Fe-P were increased in the profile of 0～80 cm soil significantly. The amount of residual total-P in the profile of 0～20 cm, 20～40 cm soil were accounting for 60.2% and 20.8% in the profile of 0-80 cm, respectively. The content of residual inorganic phosphorus were in order: Ca_2-P, Ca_8-P>Al-P>Fe-P>O-P, Ca_(10)-P. The distribution of different phosphorus fractions were that the content of total P in the profile of 20～40 cm, 40～60 cm, 60～80 cm vegetable field was accounting for 46.1%、33.2%、25.9% of in the profile of 0～20 cm, respectively, Olsen-P was 38.5%、17.3%、8.8%,Ca_2-P and Ca_8-P were accounting for 30.5%～33.6%, 16.0%～17.0%, 6.7%～22.3%. Al-P and Fe-P were 41.5%～67.0%/, 26.8%～45.7%, 17.4%～39.9%. O-P, Ca_(10)-P were 83.4%～92.9%, 77.0%～83.7%, 71.2%～81.9%, respectively. The amount of accumulated P was influenced by the status of P fractions of soils and dose of applying P fertilizer.