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Effects Of Different Fertilization Models On The Characters Of Microbes Related To Carbon And Nitrogen In Rice And Vegetable Rotation Soil In Hainan

Posted on:2021-06-02Degree:MasterType:Thesis
Country:ChinaCandidate:Y L DuanFull Text:PDF
GTID:2480306191452144Subject:Use of agricultural resources
Abstract/Summary:PDF Full Text Request
Rice-vegetable rotation is one of the important land-use rotation systems in Hainan.Fertilization mode has an important effect on the soil of Hainan rice-vegetable rotation system.In order to clarify the effects of different fertilization modes on the characteristics of soil carbon and nitrogen-related microorganisms in Hainan rice-vegetable rotation system.In this experiment,six fertilization modes were set:?RF(Recommendation fertilization for pepper,all Use fertilizer);?N0PK(no nitrogen treatment,apply all fertilizers);?HF(habits fertilization);?3/4N+1/4ON+PK-OPK(3/4 chemical fertilizer nitrogen+1/4 organic fertilizer Nitrogen+of fertilizer-Phosphorus and Potash of organic fertilizer,The same amount of nitrogen,phosphorus and potassium as the treatment1);?2/4N+2/4 ON+PK-OPK(2/4 Chemical Fertilizer Nitrogen+2/4 Organic Fertilizer Nitrogen+Chemical Fertilizer Phosphorus-potassium-organic fertilizer-phosphorus-potassium,The same amount of nitrogen,phosphorus and potassium as the treatment 1);?2/4N+1/4ON+1/4SN+PK-SPK(2/4 chemical fertilizer nitrogen+1/4 organic fertilizer nitrogen+1/4 Straw nitrogen+fertilizer fertilizer potassium and potassium-straw phosphorus and potassium,The same amount of nitrogen,phosphorus and potassium as the treatment 1).Passed 10 years(2008 to 2018)positioning test management.During the 10th rotation period of soil of rice and pepper,Studing MBC,MBN,SOC,SON,soil enzyme activity and high-throughput sequencing results of rhizosphere soil microorganisms explored the effects of different fertilization modes on soil biological indicators.The main findings are as follows:(1)The combined application mode of chemical fertilizers and organic materials can increase the soil microbial biomass carbon and nitrogen content in rice-vegetable rotation fields,and reach a significant level.During the rice growth period,the soil microbial biomass C and N contents of different fertilization patterns showed a trend of decreasing first and then rising,while the soil microbial biomass C and N contents changed during pepper growth.The peak of microbial biomass carbon content was 70 days after rice harvest and pepper planting respectively;the peak of soil microbial biomass nitrogen content was 70 days after rice seedling transplantation and 65 days after pepper planting.The soil microbial biomass carbon and nitrogen contents in the combined application mode of medium organic fertilizer at the rice stubble stage were significantly higher than those of the total inorganic fertilizer mode(RF),The average was between 31.1?182.3 and1.5?44.4mg/kg,and the contents of MBC and MBN increased by 43.25%and 136.1%on average.The highest modes of MBC and MBN in pepper during the stubble period are3/4N+1/4ON+PK-OPK and 2/4N+1/4ON+1/4SN+PK-SPK modes,which are significantly higher than all inorganic fertilizer modes(RF),with an average of between 20.0?52.4and 10.6?65.6 mg/kg,with an average increase of 67.5%and 72.3%,respectively.(2)The application of organic pig manure and straw can increase the activity of soil urease and invertase,and reach a significant level,the activity of soil catalase is not greatly affected,and there is no significant.The dynamic change of soil urease activity showed a trend of decreasing first and then increasing during the planting of the two crops,but it was inconsistent with the growth of the crop;the change trend of soil invertase activity was gradually increasing.The activity of urease and invertase were both improved by the mode of inorganic fertilizer with medium amount of organic fertilizer,which were0.22mg NH3-N/g/d and 103.4mg/g/d,respectively,which was an increase of 0.3%compared to all inorganic fertilizer models.102.4%and 0.07%?34.2%,At the same time,the urease and catalase activities of the combined application of straw and organic pig manure increased by 35.1%?58.0%and 13.5%?8.6%,respectively,compared with the single application of organic pig manure combined application mode.(3)The types of organic materials and the proportion of combined application have an impact on the structure and diversity of the microbial community.During the rice-vegetable rotation cycle,the types and abundances of soil microbial predominance in different crops changed,on the abundance and diversity of soil microbial predominance,mainly due to the combination of low amount of organic pig manure and straw,The positive effect is the highest and reaches a significant level.(4)During the rice-vegetable rotation,with the application of organic fertilizer,the biomass of carbon and nitrogen cycle-related microorganisms is increased,thereby improving the soil enzyme activity related to the carbon and nitrogen cycle,and improving the soil quality.At the same time,the soil microbial community structure is due to the organic materials.Addition,the abundance and diversity of soil microbial dominant flora have also been improved,which also confirms that the addition of organic materials changes the soil quality by changing the biological activities of related microorganisms in the soil.(5)During rice-vegetable rotation,the drastic reduction of fertilizer application rate changes the soil quality by affecting the physiological and biochemical activities of microorganisms related to the soil carbon and nitrogen cycle,rather than affecting the microbial flora structure.(6)As far as the treatment involved in this experiment is concerned,the chemical fertilizer-commercial organic pig manure-rice straw combined application mode:3/4N+1/8ON+1/8SON-PK-SPK is the optimization to maintain the soil quality of Hainan rice-crop rotation field mode.
Keywords/Search Tags:Combined application of organic materials, Rice and vegetable rotation, Soil microbial biomass, Soil enzyme activity, Soil microbial community
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