东北玉米带农田土壤磷素分布特征

Distribution characteristics of soil phosphorus in maize belt farmlands of Northeast China

对东北玉米带农田土壤全磷及有机磷在0～100cm剖面中的垂直分布及纬向分异的研究结果表明:海伦、哈尔滨、公主岭和大石桥点的土壤全磷含量随深度增加而下降,0～40cm土层全磷含量显著高于40～100cm土层(P<0.01);德惠、昌图和沈阳点40～60cm土层土壤全磷含量相对较低,但各土层之间差异不大;0～20cm土层有机磷含量显著高于20cm以下各土层(P<0.05).土壤全磷和有机磷含量随着纬度的升高而显著增加(P<0.05),气候条件和土壤类型的差异可能是导致土壤磷素纬向分布差异的主要原因.土壤全磷和有机磷含量与土壤有机碳呈极显著正相关(P<0.01),说明东北玉米带农田有机质含量是影响土壤磷素含量和分布的主要因素之一.

The study on the vertical distribution and latitudinal differentiation of soil total and organic phosphorus （P） down to 100 cm depth in maize belt farmlands of Northeast China showed that in Hailun and Harbin of Heilongjiang Province, Gongzhuling of Jilin Province, and Dashiqiao of Li- aoning Province, soil total P decreased with soil depth, being significant higher in 0-40 cm than in 40-100 cm （ P 〈0.01 ）. In Dehui of Jilin Province and in Changtu and Shenyang of Liaoning Prov- ince, soil total P was relatively lower in 40-60 cm, but no significant difference was observed among different layers. Soil organic P was significantly higher in 0-20 cm than below 20 cm （P 〈 0.05）. Soil total and organic P increased with increasing latitude （P 〈 0.05 ）. The differences in climate conditions and soil types were considered as the main reasons induced the latitudinal differ- entiation of soil P. Soil total and organic P were significantly correlated with soil organic carbon （P 〈0. 01 ）, indicating that soil organic matter was one of the most important factors affecting the soil P content and its distribution in maize belt farmlands of Northeast China.