Effect Of Several Additives On Phosphorus Leaching Of Cinnamon Soil

In the process of agricultural planting,the phenomenon of excessive fertilization is widespread in various places,causing phosphorus migration and loss in farmland soil.It is of great significance to study the phosphorus leaching phenomenon in soil.In this test,cinnamon soil was used for soil column leaching test.Low,medium and high amounts of straw(S),activated carbon(A),bentonite(B),and potassium polyacrylate(P)were added to the test soil.This test measured the concentration of TP and orthophosphate.It also measured the soil p H,EC,organic matter and TP,available phosphorus,Ca Cl2-P concentrations in different soil layers after the experiment.The main purpose was to explore the effects of different external additives on soil phosphorus leaching characteristics and better control measures for phosphorus leaching.The main findings are as follows:1.Straw significantly reduced the content of TP and orthophosphate in the leaching solution,medium-level straw significantly reduced the total phosphorus in the leaching solution(P < 0.05),low-level straw significantly reduced the content of orthophosphate in the leaching solution(P < 0.05).The orthophosphate content of low-level of activated carbon treatment was significantly lower than CK(P < 0.05).Compared with CK,the content of TP and orthophosphate of bentonite and potassium polyacrylate treatment showed no significant difference(P > 0.05).2.The content of TP and available phosphorus in the soil treated with straw did not change significantly(P > 0.05),low and high-level of straw treatment significantly reduced the Ca Cl2-P content in 0-20 cm soil(P < 0.05),and straw increased Ca Cl2-P content significantly in 20-40 cm soil,and decreased the content of Ca Cl2-P in 40-60 cm soil(P <0.05).Compared with CK,the addition of activated carbon treatment had no significant effect on the content of available phosphorus and Ca Cl2-P in soil(P > 0.05),but the addition of low-level activated carbon treatment had a significantly highertotal phosphorus content in the soil of 20-40 cm soil layer than CK.The content of TP in the soil treated with medium-level bentonite was significantly lower than that of CK(P < 0.05).The content of Ca Cl2-P in the0-20 cm soil added with bentonite was significantly lower than that of CK(P< 0.05),and had no significant effect on other contents(P > 0.05).The addition of potassium polyacrylate treatment had no significant effect on the content of TP and orthophosphate in the soil(P > 0.05),but significantly increased the effective phosphorus content in the 0-60 cm soil(P < 0.05),and also made Ca Cl2-P in the 0-20 cm soil content increased significantly(P <0.05).Potassium polyacrylate can promote the vertical migration of phosphorus in the soil along the soil column.3.In the 0-60 cm soil layer,the p H of the soil treated with potassium polyacrylate and the medium and high amount of bentonite was significantly higher than CK(P < 0.05),but in the 40-60 cm soil layer,the p H of the soil treated with low and high-level of straw and medium-level of activated carbon was significantly lower than that of CK(P < 0.05).In the 0-20 cm soil layer,the EC of different amounts of straw,activated carbon,bentonite and potassium polyacrylate treatment were not significantly different from those in the blank and CK.In the 20-40 cm soil layer,the EC of straw treated soil was significantly higher than that of CK(P < 0.05),and the EC of high-level of straw was significantly higher than that of low-level and medium-level treatment.In the 40-60 cm soil layer,the EC of soil treated by medium-level and high-level of straw was significantly higher than that of CK(P < 0.05).The EC of low-level of straw and low,medium and high-level of activated carbon,bentonite and potassium polyacrylate were not significant compared with the blank and CK.The soil organic matter content of 0-20 cm soil layer treated with straw and activated carbon content,low-level of bentonite and high amount of potassium polyacrylate was significantly higher than that of CK(P < 0.05),and the other treatments were not significantly different from CK.In the 20-60 cm soil layer,the soil organic matter content of eachtreatment did not significant different with CK(P > 0.05),but the soil organic matter content of the low-level of bentonite treatment was significantly higher than that of the medium-level and high-level activated carbon treatment at 20-40 cm soil,and is significantly higher than the low-level activated carbon treatment at 40-60 cm soil.Activated carbon and potassium polyacrylate promoted the leaching of phosphorus into the lower layer.Straw and bentonite inhibited the leaching of phosphorus in the soil.The medium-level straw had the best effect on phosphorus leaching control.