| In order to study the effects of different organic materials on paddy soil fertility and establish an eco-friendly soil fertilization model,field in-situ cultivation experiments and seven different treatments such as no fertilization(CK),chemical fertilizer(CF),Astragalus sinensis return(AS),pig manure return(PM),straw return(ST),Astragalus sinensis + straw(SP),Ziyun were conducted at Shaoxing Field Comprehensive Test Station in Ningshao Plain,Zhejiang Province.The field fertilization experiment of Ying+pig manure(AP)was conducted to study the mineralization and decomposition characteristics of organic materials and the effects of different organic materials on soil nutrients,crop yields and microbiological properties of paddy fields.The effects of soil fertilization were evaluated comprehensively.The main results were as follows:1.The decomposition characteristics of astragalus,pig manure and straw with time were studied by in situ incubation.Among the three organic materials,the mineralization decomposition rate of pig manure is the lowest,the nutrient release time is the shortest,and the mineralization decomposition rate of Astragalus is the fastest;the mineralization decomposition rate of straw is slightly slower in the early stage than astragalus,and the final decomposition rate is similar;the decomposition process of three organic materials has certain influence on soil pH,among which the soil treated by straw and pig manure is always in weak acidity,and the soil treated by Astragalus It is neutral and becomes weak acidic after 100 days.2.Field fertilization experiments were conducted to study the effects of different organic materials on soil carbon and nitrogen content and morphology in paddy fields.The application of organic materials can increase the total organic carbon content in paddy soil,and increase the content of active organic carbon and soluble organic carbon in paddy soil.The application of organic materials can effectively improve the soil nitrogen supply capacity and nitrate nitrogen content,and the application of organic fertilizer can improve the ammonium nitrogen content of soil except the treatment of Astragalus sinensis with straw.3.The effects of milk vetch,pig manure,straw and their combination on soil phosphorus,potassium and enzyme activities were studied.Compared with chemical fertilizer treatment,the application of organic fertilizer,especially pig manure,increased the content of total phosphorus and available phosphorus in soil,and the application of straw increased the content of available potassium in soil.The urease activity of soil was increased by applying organic materials(besides Astragalus sinensis returning to the field).4.Ten factors,such as total nitrogen,which can reflect the quality of soil fertility,were selected as evaluation indexes,and the soil fertility quality of different treatments was evaluated comprehensively.Seven treatments were ranked as PM > ST > AP > AS > SP > CF > CK.It was found that pig manure treatment was the best fertilizer method in the experiment. |
