| In this study, determination of inorganic P and organic P fractions, fractionated by Jiang-Gu system and Bowman-Cole method, and microbial biomassP and phosphatase activity in soil, by chloroform fumigation-extraction method and colorimetric, study effect of long-term different fertilization treatments on soil phosphorus morphology and transformation and soil profile distribution. Results showed as follows: Long-term application of fertilizers can improve soil phosphorus in cultivated layer (O0cm), especially the application of animal manure and chemical fertilizers in combination significantly increase the soil total P inorganic P and quick-available P content. Corn straw supplied with chemical fertilizer significantly increase the soil organic P. Extent of increasing content of total P inorganic P and quick-available P, chemical fertilizer treatment is lower than that of animal manure and fallow treatments, but near to that of corn straw treatments to soil total P and Olsen-P. Compare to no fertilizer treatment, the increase of soil total P inorganic P and Olsen-P of all application fertilizers treatments have different characters in O-~--- 100cm soil profile: The increase of total P and Olsen-P all can be plotted out three soil layers: the cultivated layer (0----2Ocm) 20----60cm and 60OOcm are regarded as the layer of significant amass a little increaseessen and light accumulation, respectively. The soil profile contribution of the increase of inorganic P also can be plotted out three soil layers: the layers of significant amass (0 20cm) a light accumulation (40 100cm) and transition (20?Ocm). The characters mentioned above indicated that corn straw mixed with chemical fertilizers together increase the move of organic P, while animal manure and fallow treatments significantly increase inorganic P distribution in soil profile. Organic matter content of chemical fertilizer is highest among anything else in 20挆 100cm layer, resulting in organic P content present the higher trend in the same layer. By means of comparing to IPi value and IPo value, the result show, as far as available P sources (Ca2-P - Cas-P-. Al-P) content concerned, animal manure treatment>chemical fertilization treatment>corn straw treatments; organic manure applied treatments can increase the content of organic P fractions; long term application of chemical fertilizer improve significantly content of O-P; chemical fertilizer accelerate the transforming resistant organic P to labile. moderately labile organic P. To no fertilization treatment, content of total P-. available P sources-. moderately labile P are lower, but that of Caio-P. O-P-. Fe-P are higher. To fallow treatment, content of organic matter and organic P are low, while content of labile and highly resistant P, as well as total P. Olsen-P and inorganic P are high relatively. The correlation analysis-. path analysis and step regression analysis show, Ca2-P-. Cas-P are Olsen-Pain phosphorus sources, also Al-P as well, 0-P has a remarkable negative effect to Olsen-P. Fertilization treatments increase soil microbial biomassP; similarly, phosphatase activity are increase by the fertilization of organic manure mixed with chemical fertilizers together. Calcareous soil microbial biomass P was closely related with total P-. labile organic P and Olsen-P, this suggests the utilization rate of fixed P in calcareous soil can be improved by improving soil microbial bioma... |
PDF Full Text Request