| With the increasing of planting intensity, farmland non-point source pollution that caused eutrophication of Dianchi lake stayed at a high level. The southern of Dianchi basin was the main phosphate rock base in China, and also was the main producing areas of flowers and vegetables in Dianchi basin. The unclear distribution characteristics of farmland soil phosphorus were the key factors that long-term restricted agricultural non-point source pollution prevention. In this study, through analysis of physicochemical property and forms of inorganic phosphorus between southern farmland soil profile (0-200cm),i.e. DuanQi, ZhuYuan,AnLe,GuanYinshan, and CAI river sediment(0-20cm), to help with realizing the main forms and loss characteristics of soil inorganic phosphorus in southern farmland of Dianchi basin, diagnosising the major joint and influence area of farmland phosphorus loss preliminary, providing data support for preventing farmland non-point source pollution widely. The results were as follows:In order to clear the major forms and loss of phosphorus element in the cultivated soil from Chaihe Basin, We collected0-200cm soil profile of farmland soil samples from four regions of Chaihe Basin DuanQi Village, ZhuYuan Village, GuanYin Village, AnLe Village. The sampling points were parallel tapping points on either side of the river basin in Duan Qi Village and ZhuYuan Village. At the same time, we need gathered0-20cm river sediment parallelling with sampling point.Through comparison and analysis of soil physical and chemical properties of different sampling point and the main distribution characteristics of phosphorus in farmland sampling of CAI basin, and comparison the physical and chemical properties and the distribution characteristics of phosphorus removal in farmland sampling points and river sediments, The results were as follows:(1) The analysis showed that it was obvious difference of soil mechanical composition, organic carbon, total nitrogen content and pH between the area of farmland soil. Soil organic carbon and total nitrogen content of farmland soil in GuanYinshan area(located in the lower level)(11.85g/kg,1.19g/kg) was significantly higher than DuanQi (8.42g/kg,0.95g/kg) x ZhuYuan (5.58g/kg,0.78g/kg)and AnLe(8.88g/kg,1.01g/kg);The average content of clay in AnLe area farmland soil (0-200cm) was53.5%. It was significantly higher than DuanQi (39.7%), GuanYin shan area(39.1%) and ZhuYuan area (34.3%).Soil texture in CA1river basin were clay loam, silty clay, loam clay in the order from the DuanQi to GuanYin shan area,but soil texture of AnLe area was clay;Soil pH in GuanYin shan area (7.2) was obviously higher than DuanQi(6.7), ZhuYuan(6.9) and AnLe(6.3). Soil total phosphorus content were obviously difference in CAI farmland area. The average content of soil total phosphorus in AnLe was2.49g/kg, It was significantly lower than ZhuYuan(3.65g/kg), DuanQi(3.32g/kg) and GuanYin shan (3.17g/kg) area. At the same time, the level of soil total phosphorus content were significantly decreased with the increase of depth of soil profile within0-80cm soil layer;but the change of soil total phosphorus content was not significant below80cm soil layer.The results showed that soil total phosphorus and clay content was significantly positively related (r=0.241**,n=177), soil organic carbon, total nitrogen content and soil total phosphorus content was significantly positive correlation (r=0.182**, r=0.194**, n=177). The results Showed that soil organic carbon and clay content was the important factors that affecting distribution of soil total phosphorus content.(2) The analysis showed that soil inorganic phosphorus and available phosphorus content were obviously difference in farmland area of CAI river basin.Inorganic phosphorus of farmland soil were mainly composed of Ca-P, the second was Fe-P, Al-P and O-P content were the lowest.The Fe-P content accounted for the percentage of inorganic phosphorus in ZhuYuan v GuanYinshan area and AnLe area was respectively0.39g/kg,0.33g/kg,0.29g/kg. significantly lower than DuanQi(0.57g/kg) area, but Al-P and Fe-P content were not obviously difference in GuanYinshan area and AnLe area; The Ca-P content accounted for the percentage of inorganic phosphorus in DuanQi area were0.82g/kg, respectively,significantly lower than ZhuYuan(1.36g/kg),GuanYin shan (1.28g/kg), the AnLe (0.96g/kg) area. The results showed that various forms of inorganic phosphorus content in east side of farmland surface soil (0-40cm)in DuanQi were significantly higher than west side of farmland; Different forms of inorganic phosphorus content (0-200cm) in east of farmland soil were significantly higher than that of the west side in ZhuYuan area;The content of Ca-P, Al-P and O-P in east farmland surface soil (0-20cm) of GuanYin shan and ZhuYuan were higher than that of west farmland, but Fe-P content in GuanYin shan east farmland surface soil (0-20cm)was significantly lower than west farmland. This may be associated with planting mode on both sides and phosphate rock distribution. Soil pH, soil density and soil inorganic phosphorus content were not significantly negative correlation.Except Ca-P, soil clay content and Al-P were significantly positive, soil organic carbon content, total nitrogen and Al-P were significantly positive correlation.The research results showed that soil organic carbon content and particle size distribution were the main factors that influenced the soil P. Soil pH, soil density influenced distribution of soil p content.(3) The analysis showed river sediment pH of GuanYinshan area (6.7) was lower than DuanQi (6.8)、ZhuYuan(6.9)、AnLe (6.8).AnLe. Sediments clay content in AnLe area was42.69%on average,significantly higher than the GuanYinshan (27.4%), ZhuYuan (20.0%), DuanQi(18.10%). Inorganic phosphorus of river sediment in CAI river basin were mainly composed of Ca-P, the second was Fe-P, Al-P and O-P content were the lowest.Total phosphorus content of river sediment was6.12g/kg in GuanYin shan area, It was significantly higher than DuanQi (3.52g/kg),ZhuYuan (3.82g/kg),AnLe(3.94g/kg) area.Research results showed that total phosphorus content was significantly positive relate (r=0.531*, n=6) between river and east farmland surface soil except the GuanYin area, and it was no significantly correlation between total phosphorus content between river and west farmland surface soil, This suggested that the phosphorus in river sediment was mainly derived from east farmland. Research results showed that Al-P content was significantly positive relate (r=0.744*, n=8) between river and east farmland surface soil, and it was no significantly correlation between Al-P content between river and west farmland surface soil, This suggested that the Al-P in river sediment was mainly derived from east farmland. Research results showed that Ca-P content was significantly positive relate (r=0.756*, n=8) between river and west farmland surface soil, and it was significantly positive relate (r=0.897**, n=8) between river and west farmland surface soil, This suggested that the Ca-P in river sediment was mainly derived from east and west farmland. |
PDF Full Text Request