Soil Phosphorus Utilization And Phosphorus Loss In Maize Soybean Intercropping System Under Reduced Phosphorus Application

The increase of crop yield in agricultural production can not be separated from the input of phosphate fertilizer,but excessive input will lead to the waste of resources and the imbalance of the ecological environment.In order to solve this problem,a series of techniques to improve the utilization of phosphorus and reduce the loss of phosphorus have come into being.This paper takes the field experiment of teaching farm in Sichuan Agricultural University as the research object,and set up three planting patterns of maize soybean intercropping?M/S?,maize single cropping?M?,soybean single cropping?S?,regular phosphate fertilizer?CP?,phosphate fertilizer 20%?RP?,and non phosphate fertilizer?P0?,three phosphorus application levels,the characteristics of crop yield,dry matter accumulation,phosphorus uptake,phosphorus utilization,soil phosphorus availability and phosphorus adsorption and desorption were studied under different planting patterns and phosphorus application levels,The crop control technology,which can reduce crop loss and reduce the risk of phosphorus loss,the results are as follows:?1?In the unit of land area,compared with monocrop pattern,intercropping significantly increased the dry matter accumulation,grain yield,phosphorus uptake of corp and phosphorus apparent utilization efficiency.Maize monocorp pattern,with the amount of phosphorus decreased,maize grain yield,dry matter accumulation,phosphorus uptake of corp decreased,soybean monocorp pattern,with the amount of phosphorus decreased,soybean grain yield,dry matter accumulation,phosphorus uptake of corp decreased,both of them the phosphorus apparent utilization efficiency were improved,but the difference was not significant,While in maize and soybean intercropping,compared with CP treatment,RP treatment increased the maize and soybean dry matter accumulation,phosphorus uptake of crops and phosphorus apparent utilization efficiency,the phosphorus apparent utilization efficiency increased significantly,maize and soybean were increased by 35.6%and 41.8%.?2?The three rate of phosphorus,compared with monocorp pattern,maize and soybean relay intercropping pattern soil total phosphorus,available phosphorus and the activity of acid phosphatase were increased significantly,the average phosphorus content of soil increased by8.7%and 7.5%respectively,the average value of available phosphorus increased by 9.4%and14.8%respectively,and the average value of acid phosphatase activity increased by 13.1%and 9%respectively.Under the intercropping pattern,compared with CP treatment,RP treatment increased the soil available phosphorus content of maize belt and soybean belt and increased by 13.3%and 10%respectively,and the activity of acid phosphatase increased by17.5%and 4%respectively.The maize belt of soil phosphorus fractions except NaOH-P_i and Residual-P,the rest of the phosphorus fractions were showing intercropping was lower than monocorp,and the difference was significant.Compared with soybean monocorp pattern,intercropping pattern the soybean belt soil's NaHCO₃-P_i,NaHCO₃-P_o,NaOH-P_i,NaOH-P_o and HCl-P_i were decreased,and the differences are significant.In the case of phosphate fertilizer,both the monocropping and intercropping RP treatment phosphorus fractions were significantly lower than that of CP treatment,when the phosphate fertilizer has been reduced by 20%in maize and soybean intercropping system?M/S-RP?minimum.?3?When the phosphate fertilizer has been reduced by 20%in maize and soybean intercropping system,the maximum adsorption amount of soil phosphorus?X_m?,the buffer capacity of the solute adsorption of solid-liquid system?MBC?is the largest,to measure the adsorption desorption?b?minimum total phosphorus content in surface runoff is relatively low,showed that the phosphorus retention strong,can effectively reduce the risk of phosphorus loss.In short,when the phosphate fertilizer has been reduced by 20%in maize-soybean intercropping system,the dry matter accumulation,yield,phosphorus uptake,phosphorus loss control is superior to the other monocrop.The test has an important role in increasing the cost of production and reducing the risk of phosphorus loss,and it is a technology that can be used to promote the application.