湖南省几种主要母质类型菜园土壤的磷素状况

Phosphorus Status in Vegetable Soils Derived from 3 Types of Parent Material in Hunan Province

通过野外土壤调查取样与室内分析,研究了湖南省3种母质类型发育的菜园土壤的磷素状况,并对土壤磷素活化系数及磷的迁移淋溶进行了简要的分析。结果表明,由河流沉积物发育的冲积菜园土全磷和有效磷含量最高,平均分别达2.04g/kg和194.7mg/kg,磷素活化系数(PAC)为6.7-12.9,平均9.6;第四纪红土发育的红菜园土全磷和有效磷含量其次,平均分别为1.28g/kg和102.8mg/kg,PAC为1.9-12.1,平均6.8;洞庭湖湖积物发育的潮菜园土全磷和有效磷含量平均分别为1.18g/kg和30.5mg/kg,PAC为1.3-4.7,平均2.5。土壤无机磷是土壤磷素的主要形态,红菜园土中无机磷占全磷的比例为79.8%,磷素形态以O-P和Fe-P为主(占57.7%);冲积菜园土无机磷占全磷的比例为89.0%,磷素形态以Fe-P为主(占36.6%);潮菜园土无机磷占全磷的比例为85.0%,磷素形态以Ca-P为主(占88.1%)。土壤有机磷组分以中活性有机磷(MLOP)和中稳性有机磷(MROP)为主,占土壤有机磷总量的80%以上。Ca2-P、Al-P、Fe-P、LOP(活性有机磷)、MLOP(中活性有机磷)是作物的有效磷源,Ca8-P、O-P、Ca10-P和MROP(中稳性有机磷)、HROP(高稳性有机磷)为作物的潜在磷源。

Through soil sampling on field and laboratory analysis, phosphorus status of vegetable soils derived from 3 types of parent material was studied in Hunan Province, and the phosphorus activation coefficient （PAC） and phosphorus loss was also briefly analyzed. The results showed that total P and available P contents in vegetable soil derived from river alluvium are the highest, and amount to 2.04 g/kg and 194.7 mg/kg in average respectively, and PAC is 6.7-12.9 and 9.6 in average. The average contents of total P and available P in vegetable soil derived from Quaternary red clay follow the second, and are 1.28 g/kg and 102.8 mg/kg respectively, and PAC is 1.9-12.1 and 6.8 in average. The average contents of total P and available P in vegetable soil derived from lake sediment of Dongting lake are the lowest and 1.18 g/kg and 30.5 mg/kg in average respectively, and PAC is 1.3- 4.7 and 2.5 in average. Inorganic P is the main form of soil P. It accounts for 79.8% of total P and its main inorganic P is O-P and Fe-P （account for 57.7%） in vegetable soil derived from Quaternary red clay, it accounts for 89.0% of total P inorganic P in the soil derived from river alluvium and its main inorganic P is Fe-P （account for 36.6%）, and it accounts for 85.0% of total P in the soil derived from lake sediment and its main inorganic P is Ca-P （account for 88.1%）. Moderately labile organic phosphorus （MLOP） and moderately resistant organic phosphorus （MROP） are 2 main organic P forms, and account for 80% of total organic P. CaE-P, Al-P, Fe-P, LOP （Labile organic P） and MLOP are available phosphorus source to crop, and Ca8-P, O-P, Ca10-P, MROP and HROP（Highly resistant organic P ） are the potential source of phosphorus to crop.