Effect Of Edamames [Glycine Max(L.) Merr.] Green Manure Mixed With Phosphate Fertilizer On The Phosphorus Movement And Transformation At The Manure Microsite In Paddy Soils

Rice as a major grain crop plays an important role in maintaining the food security of our country,but poor soil phosphorus availability and low phosphate fertilizer utilization rate are the restricted factors in the development of rice industry.After the leguminous green manure contained a large amount of phosphorus and the other nutrients is applied,it will form a microsphere near the manure,which will affect the form and availability of phosphorus.In this thesis,a soil column culture test is conducted in the laboratory,Bowman-Cole organic phosphorus fractionation and Zhang-Jackon soil inorganic phosphorus classification method were used to determine the content of different forms of phosphorus,and six treatments were analyzed: Control(without application phosphate fertilizer and green manure,phosphate fertilizer(single application of phosphate fertilizer),15 t/ha edamame green manure(single application of low amount of green manure),15 t/ha edamame green manure + phosphate fertilizer(low amount of green manure mixed with phosphate fertilizer),22.5 t/ha edamame green manure(single application of high amount of green manure),22.5 t/ha edamame green manure + P fertilizer(high amount green manure mixed with P fertilizer)on phosphorus content and variation regularity of different forms in paddy soil.In order to clarify the effect of edamame green manure on phosphorus availability of paddy soil,and to provide theoretical basis for its rational use.The main results are as follows:(1)Before 14 days incubation,the mixed application of phosphate fertilizer inhibited the decomposition of green manure.With the increase of culture time,the inhibitory effect was gradually weakened.After 28 days of culture,the decomposition rate of the two treatments with mixed phosphate fertilizer was significantly higher than that with green manure alone(p<0.05).(2)Application of green manure and green manure combined with phosphate fertilizer can increase the movement distance,content and accumulation of the four kinds of organic phosphorus in soil.The 28 days and 14 days rule is almost the same,but the increase scale is larger.After 28 days of culture,green manure application could significantly increase the contents of active organic phosphorus,medium active organic phosphorus,medium stable organic phosphorus and high stable organic phosphorus in soil.Compared with the control,the increases were 83.32%-304.41%,133.22%-449.99%,31.62%-96.31%,23.32%-264.66%(p<0.05).The organic P content in the green manure combined with phosphate fertilizer treatment was significantly increased by 35.60%-96.78%,57.74%-85.86%,26.89%-41.58%,9.22%-20.68%compared with that of green manure alone(p<0.05).The application of high green manure had more promoting effect than that of low green manure,and the increase range of four kinds of organic phosphorus was 17.43%-170.74%(p<0.05).The content of moderately active organic phosphorus in four kinds of organic phosphorus was significantly increased by applying green manure.The migration distance,content and accumulation of four kinds of organic phosphorus were most affected by high amount of green manure combined with phosphorus fertilizer.(3)Application of green manure and green manure combined with phosphate fertilizer can increase the migration distance,content and accumulation of four inorganic phosphorus in soil.The 28 days and 14 days rule is basically the same,but the increase range is larger.After 28 days of culture,green manure could significantly increase the contents of Al-P,Fe-P,Ca-P and O-P in soil,and the increases were 11.22%-42.35%,55.43%-194.49%,32.83%-135.22%,2.97%-13.76% compared with the control(p<0.05).The content of green manure combined with phosphate fertilizer also increased significantly by 18.60%-18.88%,65.96%-89.47%,13.16%-17.85%,1.44%-2.98%compared with that of green manure alone(p<0.05).The application of high green manure had more promoting effect than that of low green manure,and the increase range of four inorganic phosphorus was 7.67%-56.47%(p<0.05).The content of Fe-P in four kinds of inorganic phosphorus was significantly increased by green manure application.High green manure combined with phosphate fertilizer had the greatest influence on the migration distance,content and accumulation of four inorganic phosphorus.(4)With the increase of incubation time,the application of green manure can improve the soil pH.The 28 days and 14 days rule is basically the same,but the increase is larger.After 28 days of incubation,the pH of high quantity green manure mixed with phosphate fertilizer was 7.05,which increased the most.The pH of low green manure treatment was 5.30,which was lower than that of control(p<0.05).In conclusion,with the increase of time,the application of green manure can significantly increase the migration distance,content and accumulation of different forms of organic phosphorus and inorganic phosphorus in soil at the microsite in this research.With the increase of rate,the effect could be significantly strengthened.Green manure mixed with phosphate fertilizer also had significant promoting effect.Mixed application of phosphate fertilizercan increase the decomposition rate of green manure.Applying green manure can increase soil pH,improve soil fertility characteristics,provide a good growing environment for crop development,achieve efficient fertilizer saving,and develop new green agriculture.