Study On The Effect Of Reducing The Application Of Chemical Fertilizers And Applying Organic Fertilizers On The Quality And Efficiency Of Litchi

Litchi(Litchi chinensis Sonn)is one of the main tropical economic crops in my country,which plays an important role in the development of local rural economy and farmers’ income.Because farmers blindly pursue high yields and apply large amounts of chemical fertilizers for a long time,problems such as element enrichment,soil acidification,soil microbial flora imbalance,and soil quality decline have been caused.As a result,the production of litchi has decreased,economic benefits have fallen,and the planting area has decreased,which has severely restricted the development of my country’s litchi industry.A large number of studies have proved that the combined application of chemical fertilizers and organic fertilizers can increase soil fertility and microbial diversity,improve the soil environment,thereby maintaining sufficient and continuous supply of nutrients,promoting plant growth and development,improving yield and quality,and improving economic benefits.Therefore,this study carried out the investigation of soil fertility,fertilizer input and nutrient removal in the main litchi producing areas to find out the lack of nutrient management in litchi and propose solutions.Based on the investigation,a typical litchi orchard in Hainan was selected to carry out a study on reducing the application of chemical fertilizers and applying organic fertilizers to explore the effects of different amounts of sheep manure organic fertilizer and bio-organic fertilizer on the growth,yield and quality,fertilizer utilization,and economic benefits of litchi;under equal nutrient conditions Next,using sequencing technology,comparing the changes of soil fertility and microbial flora under organic fertilizer application and chemical fertilizer treatment,the mechanism of organic fertilizer improving yield and quality was preliminarily discussed,and the theoretical basis for building a high-yield,stable-yield,high-quality nutrient management system for litchi was improved.1.The survey of soil fertility,nutrient input and take-out in the main litchi producing areas shows that there are insufficient litchi nutrient management.The soil fertility surveys in Guangxi and Hainan showed that the soil p H of the litchi orchards in the two places was4.66 and 5.05,respectively,and acidification was serious;the average organic matter content of the litchi orchards in the two places were 17.94 and 31.22g/kg,respectively.The average content of alkaline hydrolyzed nitrogen in the two places was 143.33 and 114.72g/kg,the average available phosphorus was 54.09 and 95.39 mg/kg,and the average available potassium was 99.13 and 162.16 mg/kg.The average effective calcium is 217.65,386.06 mg/kg,the average effective magnesium is 21.64,73.94 mg/kg,the average effective iron is 38.45,41.50 mg/kg,the average effective manganese is 16.29,45.57 mg/kg,and the average effective copper is 2.54.2.37mg/kg,the average effective zinc is 2.14 and7.72 mg/kg.The content of available calcium and magnesium in litchi orchards in the two places is relatively low.The content of organic matter in litchi orchards in Guangxi is low,and the levels of available phosphorus and potassium are moderate.The alkali hydrolyzable nitrogen,available phosphorus and available phosphorus in Hainan litchi orchards are relatively high.The fertilizer inputs of the three provinces(autonomous regions)are N189.78,P2O5 132.75,K2 O 200.64 kg/hm2,and the organic fertilizer inputs are N 75.38,P2O5 53.25,K2 O 32.32 kg/hm2,and the proportions of organic fertilizers are N,P,and K respectively.They were 28.4%,28.6%,and 13.8%.The nutrient removal of Feizixiao litchi is N 104.77,P 10.29,and K 92.92 kg/hm2.The three provinces(autonomous regions)are not using enough organic fertilizer,and Hainan and Guangdong are using too much fertilizer.2.Reduced application of chemical fertilizers and combined application of organic fertilizers in typical lychee gardens in Hainan has a significant effect of improving quality and efficiency.5 treatments,each treatment in 2018(2019)is a chemical fertilizer treatment(CF),under the condition of reducing chemical fertilizer by 30%(reducing nitrogen by11%),combined with 5(4)kg and 10(6)kg sheep manure organic fertilizer Treat OF5(OF4),OF8(OF6),and apply 5(2)kg and 10(3)kg of bio-organic fertilizer to treat BIO5(BIO2)and BIO10(BIO3).The specific results are: In 2018,compared with CF,OF5 significantly promoted the growth of new shoots,and BIO5 significantly increased the chlorophyll content of leaves at the shoot stage.There was no significant difference in leaf nutrient content between the various treatments in the shoot stage and fruit ripening period,and the nutrient content and change trend were in line with the growth law of litchi.Compared with CF,treatments of BIO5,OF10,and BIO10 all significantly increased the yield of litchi per plant,the increase was 44.77%,35.81%,18.23% respectively;the internal quality of litchi fruit under the organic fertilizer treatment was higher than that of the CF treatment,and the soluble solid content was average Increased by 1.76%-3.22%,soluble sugar content increased by 11.96%-21.84% on average,titratable acid content decreased by 15.38%-35.35% on average;comprehensive evaluation of yield and quality BIO5>BIO10>CF>OF10>OF5.In 2019,BIO2 treatment tip The total length and slightly coarser are significantly higher than other treatments,and are 51.1% and 10.0% higher than CF treatment.The trend of leaf nutrient content in each treatment was consistent with the previous year.Compared with CF,BIO2 treatment yield increased by 33.06%,Vc content increased by 32.94%,titratable acid content decreased by 32.27%,sugar-acid ratio increased by 40.91%,BIO2 treatment had the highest edible rate,reaching 76.68%;comprehensive evaluation of yield and quality It is BIO3> OF6> BIO2> CF> OF4.The two-year average fertilizer utilization results showed that the partial nitrogen productivity of all organic fertilizer treatments was significantly higher than that of chemical fertilizer treatments,and the partial productivity of nitrogen,phosphorus,and potassium fertilizers and the agronomic utilization rates of nitrogen and phosphorus were significantly higher in BIO5(2)and OF10(6).For other treatments.OF10(6),BIO5(2),BIO10(3)can significantly increase the income of litchi.3.Select chemical fertilizer treatment,sheep manure organic fertilizer 6kg treatment and bio-organic fertilizer 2kg treatment for microflora research,indicating that increasing organic fertilizer and reducing chemical fertilizer can change the soil microbial flora.For two consecutive years,reducing the application of chemical fertilizers and applying sheep manure and bio-organic fertilizer can effectively increase the yield,with an average increase of 23.1%(sheep manure organic fertilizer)and 39.0%(bio-organic fertilizer)respectively.The content of soil organic matter and p H increased significantly,and the content of soil available phosphorus,available potassium,available calcium,available magnesium,available iron,available manganese,available copper and available zinc all increased to varying degrees.The application of bio-organic fertilizer treatment can increase the abundance and diversity of rhizosphere soil bacteria and fungi,and the organic manure of sheep manure can increase the diversity of rhizosphere soil bacteria and fungi.BIO treatment had the most unique bacterial species(9750),and the number of unique fungal species in BIO treatment(2108)was greater than that of OF treatment(2013)and greater than that of CF treatment(1417).The application of two kinds of organic fertilizers significantly changed the structure of soil microbial community,increased the eutrophic bacteria groups such as Bacteroides,Proteobacteria,and Bacillus phylum,and reduced oligotrophic fungi such as Acidobacteria and Chlorocurve phylum.Taxa.Compared with CF,the relative abundances of MND1 mesh,KD4-96 mesh,Gemmatimonas,Pseudolabrys,Trichoderma and Botryotrichum under OF treatment and BIO treatment are all Significantly improved,and has a significant positive correlation with yield.To sum up,Guangxi and Hainan provinces(autonomous regions)have serious soil acidification in litchi orchards,lack of calcium and magnesium content,fertilizer input is mainly chemical fertilizer,and nitrogen and phosphorus input is too much,potassium fertilizer is insufficient,and organic fertilizer input should be paid attention to;Experiments show that plant application of biological organic fertilizer 3kg-5kg(1620kg/hm2-2700kg/hm2)or sheep manure organic fertilizer 6kg-10kg(3240kg/hm2-5400 kg/hm2)has a significant effect of improving quality and efficiency;combined application of organic fertilizer Improve soil fertility,increase microbial activity,reshape the microbial flora beneficial to litchi,and increase litchi yield.