菜园土肥力特征及蔬菜硝酸盐污染的控制技术 Ⅰ.长沙市郊专业蔬菜基地土壤磷素状况及无机磷形态的分级

Study on Fertility of Vegetable Soil and Controlling Technique for Pollution of Nitrate in Vegetable Crops Ⅰ.The Phosphate Status and Fractionation of Inorganic Phosphate in Some Vegetable Soils of the Suburbs of Changsha

为探明长沙市郊蔬菜基地菜园土磷素状况及上壤供磷水平，采用野外取样调查和室内分析栩结合，对两种主要母质发育的菜园土耕作层和剖面分层样品进行了研究．结果表明，1)长沙市郊几个蔬菜基地土壤全磷和有效磷含量均较高，全磷含量0．78～2．72g／kg，平均172g／kg，有效磷12．82～286．7mg／kg，平均156．7mg／kg；2)土壤磷以无机磷形态为主，其变动范围为584．7～2607.5mg／kg，平均1495．7mg／kg，占全磷量的74．96％～95．86％，均显著高于其他农业土壤和自然土壤，是菜园土的一大显著肥力特征；3)土壤无机磷组成因成土母质不同而不同，第四纪红土母质发育的菜园土O-P含量最高，其次是Fc-P，Al-P较少，而由河流冲秘母质发育的菜园土Fc-P含量最高，其次是Al-P和O-P；4)无机磷是土壤有效磷的主要来源，Ca2-P，Ca8-P，Al-P和Fe-P均与土壤有效磷呈极显著正栩关．

To ascertain phosphate status of vegetable soils in the suburbs of Changsha, the mixed soils of plough layer and profile soils were studied by investigation and analysis.The results are as follows,1) The contents of total P and available P in vegetable soils were much higher than the agricultural sails and natural soils.Total P varied from 0.78 to 2.72 g/kg and its average was 1.72 g/kg.The available P varied from 12.82 to 286.7 mg/kg and its average was 156.7 mg/kg.2) The main phosphate fraction was inorganic P in vegetable soils, and up to 74.96%～95.86% of total P.It varied from 584.7 to 2 607.5 mg/kg and its average was 1 495.7 mg/kg.3) The inorganic phosphate fractions varied with parent material in vegetable soils.Soils that derived from the quaternary red clay, had more O-P,Fe-P,Al-P was less, while the soil that derived from rive alluvium had more Fe-P,Al-P and O-P was less.4) The correlation analysis showed that the main resources of available P was inorganic P,and the correlation coefficient between available P and Ca2-P,Ca8-P,Al-P,Fe-P was significant.