松辽平原农田土壤碳氮磷分布特征研究

本文对东北地区松辽平原不同纬度农田土壤碳氮磷剖面分布特征进行比较研究，从北到南依次采集了黑土区的海伦、哈尔滨、德惠、公主岭和棕壤区的昌图、沈阳、大石桥玉米地土壤样品。所得主要结论如下： 各样点土壤有机碳含量随土层深度的增加而下降。海伦、哈尔滨和公主岭样点40～60cm土层土壤有机碳含量及其储量显著低于0～40cm土层；海伦、哈尔滨、德惠、公主岭和昌图样点土壤水溶性有机碳表现出随深度增加先升高后降低，在沈阳和大石桥样点土壤水溶性有机碳表现出随深度而下降的趋势；各样点0～20cm土层土壤微生物量碳含量高于20～40cm土层。典型黑土区海伦点0～100cm的SOC储量为213.4t•hm-2, 棕壤区昌图、沈阳、大石桥样点分别为69.9、87.9和73.4t•hm-2，海伦点SOC储量是棕壤区三样点的3倍左右。 土壤全氮、碱解氮、硝态氮及氮储量随剖面深度增加而下降。德惠点在20～40cm土层、沈阳点在40～60cm土层、昌图点在60～80cm土层的全磷含量最低；其他样点土壤全磷、有机磷含量和磷储量总体上呈现随土层深度增加而下降的趋势。黑土区样点土壤有机磷含量在40cm以下各土层迅速下降，而棕壤区各样点20cm以下各土层差异不显著。除公主岭和大石桥点外, 其他各样点土壤Olsen-P含量在0～20cm 土层显著高于20～40cm土层。 土壤有机碳、全氮、碱解氮、全磷和有机磷含量随纬度增加而增加。营养元素在纬度上的分异主要受成土母质、气候条件等自然因素影响，施肥、耕作等人为活动对表层土壤营养元素分布的影响较大。除土壤水溶性有机碳外，土壤碳、氮和磷之间及其与其他基本理化性质间均存在显著的相关关系。

The profile distribution of soil C, N, and P in Songliao Plain of Northeast China along a latitudinal gradient was studied. Soil samples were collected from maize fields in Hailun, Harbin, Dehui, and Gongzhuling of the black soil region, and Changtu, Shenyang, and Dashiqiao of the brown soil region. Following results were obtained: Soil organic carbon (SOC) decreased with the increasing of depth. Soil organic carbon and its storage in Hailun, Harbin and Gongzhuling sites were significant lower at the depths of 40-60cm than at 0-40cm. Soil dissolved organic carbon (DOC) decreased first and then increased in profiles of Hailun, Harbin, Dehui, Gongzhuling and Changtu sites, while it was decreased with depth in both Shenyang and Dashiqiao sites. Microbial biomass carbon content was higher at the depth of 0-20cm than at 20-40cm in esch site. The SOC storage at the depth of 0-100cm was 213.4t•hm-2 in Hailun site from the typical black soil region, while it was 69.9, 87.9, and 73.4t•hm-2 in Changtu, Shenyang, and Dashiqiao sites, respectively, from the brown soil region. The SOC storage was about 3 times as much in Hailun site as in the three sites from the brown soil region. Soil total N, alkali N, NO3--N and N storage decreased with the increasing of depth. The lowest content of soil total P in profiles was appeared in 20-40cm layer of Dehui site, 40-60cm layer of Shenyang site, and 60-80cm layer of Changtu site. Soil total P, organic P and P storage presented decreasing trends with the increasing of depth in the other four sites. In the four sites from the black soil region, soil organic P was not significantly different between 0-20cm layer and 20-40cm layer, but it desreased rapidly in layers below 40cm. In the three sites of the brown soil region, soil organic P was not significantly different among layers under the 20cm depth. Except for Gongzhuling and Dashiqiao sites, soil Olsen-P was significant higher in the 0-20cm layer than in 20-40cm layer. Soil organic C, total N, alkali N, total P and orgnic P were increased with the increasing of latitudes. The latitudial differences of mutrients were mail affected by mutrual factors such as parents and climate conditions, while the distubution of nutrients in the surface layer was also affected by anthropic activities such as fitilization and tillage. Significant correlations were found among SOC, N and P, and with other basic physico-chemical properties, except for DOC.