Effects Of Lime-ammonium Bicarbonate Fumigation In An Orchard With Serious Fusarium Wilt Disease And Substitution Of Chemical Nitrogen With Organic Fertilizer

In recent years,the banana successive cropping obstacle is increasingly serious,in Hainan province,because of the declining soil fertility and unbalanced soil microflora,banana wilt is caused,which makes the plant area reduced from its peak of 870,000 mu to harvest area of only 260,000 mu in 2016;it is a serious threat to the banana industry development,as a result of it,there are a large number of abandoned banana plantation in Hainan.The study selects discarded continuous cropping banana plantation soil and adopts the method of lime-ammonium bicarbonate fumigation combined organic fertilizer to study the effect and mechanism of repairing discarded banana plantation,meanwhile,the amount of organic fertilizer replacing inorganic nitrogen fertilizer is determined,the main results are as follows:1)Lime-ammonium bicarbonate fumigation(LFC)obviously changed banana rhizosphere microbial community structure,reduced some relative abundance of potential pathogenic microbiology,such as Moritierella and Sarocladium,as well,the relative abundance of part of antagonistic bacteria is improved,such as Streptomycetaceae,Sinomonas and microzyme.LFO significantly improve the pH of soil,at the same time,soil organic content is increased,and the soil nutrient content is significantly improved.LFC significantly reduces the Banana Fusarium wilt disease,compared with the CF,in two seasons,it reduced by 13.98%and 33.01%respectively,which brought a significant increase in banana production,compared with the CF,in two seasons,it increased by 30.11%and 87.67%respectively.2)lime-ammonium bicarbonate fumigation with organic fertilizer(LFO)obviously changed banana rhizosphere microbial community structure,relative abundance of Fusarium significantly reduced,as well,the relative abundance of part of antagonistic bacteria is improved,such as Streptomyces,Rhodococcus and Actinomycetes.LFO significantly improve the pH of soil,at the same time,soil organic content is increased,and the soil nutrient content is significantly improved.Banana Fusarium wilt disease be significantly reduced by LFO,compared with LFC,the two seasons were reduced by 15.30%and 20.34%respectively,and the banana yield was significantly increased.Compared with CF,the yield increased by 9.45%and 16.18%respectively in the two seasons.Therefore,LFO can effectively improve the rhizosphere microbiological community structure,which helps to significantly improve the soil quality of abandoned banana plantation and provide a feasible way for replanting.3)20%-40%of chemical fertilizer replaced by organic fertilizer can meet the needs of normal growth,and compared with chemical fertilizer,by using the alternative processing,banana Fusarium wilt disease decreased significantly,the yield increased significantly;chemical fertilizer replaced by organic fertilizer,soil organic matter can be improved,and improved soil pH significantly,additionally,the available of nitrogen,phosphorus,potassium are added;meanwhile,the number of culturable Fusarium and fungi can be reduced while increasing culturable bacteria,improving B/F.Once 30%-40%chemical fertilizer replaced by organic fertilizer n,the normal growth of bananas is available and soil quality and soil microbial community structure could be improved while it has a significant effect on disease depression.