绿肥季施用磷矿粉对稻田土壤磷有效性及水稻产量的影响OA

In rotation of rice and green manure crops,the effects of phosphate rock powder replacing chemical phosphate fertilizer on the yield and phosphorus absorption of subsequent rice crops,soil phosphorus pool and phosphatase activity of subsequent rice were explored,which could provide theoretical support for the use of phosphate rock powder instead of phosphate fertilizer in the green manure rice rotation system in Sichuan hilly region.In the field experiment,two planting patterns of winter fallow(WF)and winter Chinese milk vetch(GM)were set up,and three phosphorus fertilizer treatments were applied,including no phosphorus fertilizer(P0),phosphorus fertilizer in rice season(P1),and phosphate rock powder in green fertilizer season(P2).The effects of different phosphorus application measures on rice yield,phosphorus uptake,soil total phosphorus,available phosphorus,phosphorus components and phosphatase activity were analyzed under two planting patterns.The results showed that compared with WF-P1,the total soil phosphorus and microbial biomass phosphorus contents of GM-P2 were increased by 0.12 g/kg and 1.05 mg/kg,respectively.The activities of acid phosphatase and alkaline phosphatase were increased by 31.46％and 34.47％,respectively.The content of 0.5 mol/L NaHCO3-extractable organic phosphorus(NaHCO3-Po)was increased significantly by 19.92％,while the content of high-concentration HCl-extractable inorganic phosphorus(HHCl-Pi)was decreased significantly by 22.40％.The content of high-concentration HCl-extractable organic phosphorus(HHCl-Po)was increased significantly by 136.49％,and the rice yield was increased significantly by 7.76％.Under the two cropping systems,compared with the phosphorus-free treatment,the phosphate rock powder application treatment resulted in increases in total soil phosphorus content,acid phosphatase activity,and rice yield.In comparison with the conventional phosphorus fertilizer application treatment,the phosphate rock powder application treatment led to a higher total soil phosphorus content but a lower available phosphorus content,while there was no significant difference in rice yield.Under the phosphate rock powder application method,compared with the WF treatment,the GM treatment showed significant increases in soil microbial biomass phosphorus content,NaHCO3-Po content,alkaline phosphatase activity,and rice yield by 0.63 mg/kg,15.57％,18.66％,and 6.51％,respectively.The results of path analysis showed that soil total phosphorus,microbial biomass phosphorus,acid phosphatase,and 0.5 mol/L NaHCO3-extractable inorganic phosphorus(NaHCO3-Po)exerted positive effects on rice yield,among which microbial biomass phosphorus content had the strongest positive effect.In contrast,HHCl-Pi and 0.5 mol/L NaHCO3-extractable inorganic phosphorus(NaHCO3-Pi)exhibited negative total effects,with HHCl-Pi showing a stronger negative effect.In conclusion,compared with the model of applying phosphorus fertilizer in the winter-fallow rice season,the practice of intercropping Chinese milk vetch(Astragalus sinicus L.)in winter combined with phosphate rock powder application could significantly increase soil microbial biomass phosphorus content and phosphatase activity,mediate the transformation process of phosphorus fractions,thereby improving soil phosphorus availability and increasing phosphorus uptake by rice plants,and ultimately achieving rice yield increase.Therefore,this practice could be used as a suitable fertilization model for paddy fields in the hilly areas of Sichuan province.