Development And Application Of Organic Tobacco Straw Fertilizer For Soil Improvement

China is the country with the largest tobacco planting area in the world(1.081×106 hectares,2017),which produces a large amount of tobacco straw waste(about 4.5 million tons)every year.Green comprehensive utilization of straw resources has attracted much attention,but most of them only focus on the utilization of crop straw with light texture and low lignocellulose content,such as corn and sorghum,etc.The progress of comprehensive utilization of tobacco straw and its economic benefits need to be further studied.However,many factors,such as dispersed raw materials,difficult storage and transportation,energy consumption of pretreatment and so on,lead to the cost of comprehensive utilization of tobacco straw in China.It is a low-cost and less environmental pollution method to treat tobacco straw by thermophilic aerobic composting,which is a potential effective measure to realize the recycling of tobacco straw resources.For the purpose of degrading tobacco straw,samples were collected from natural rotten wood piles,tobacco straw and wood waste piles.Through enrichment,primary screening,re-screening and antagonism experiments,Excellent strains named mold A(Trametes sp.),N019a(Lysinibacillus fusiformis)and imp(Rhizopus oryzae),were obtained through a series of experiments such as enrichment,primary screening,re-screening and antagonism.The Li P,Mn P and Lac enzymes activities of mold A reached 465.24 IU/g?264.15 IU/g and1818.23 IU/g,respectively.The three strains screened in this experiment were unantagonistic to cellulose-degrading strains B4,B26 and M90 and nicotine-degrading strain P3 a preserved in the laboratory.And a microbial agent was blended by all those strains due to their compatibility.The solid fermentation was carried out on solid-state tobacco stalk granular medium.The results showed that the degradation rate of hemicellulose,cellulose and lignin were reached 82.32,70.21% and 64.13% after 25 days respectively.Compound decomposing agent was divided into mixed bacteria(N019a,B4,B26 and P3a)and fungi(mould A,M90 and imp).The fermentation process was optimized separately.After optimization,the fermentation process of mixed bacteria was as follows: sucrose 30 g/L,corn flour 20 g/L,bean pulp 60 g/L,K2HPO4 1.0 g/L,Mg SO4.7H2 O 0.5 g/L,KCl 0.5 g/L,Fe SO4 0.01 g/L,fermentation temperature 35?,fermentation time 24 h,using Fermentation Tank.The optimum fermentation conditions of fungi were as follows: mold A was cultured in PDA liquid medium(containing potato microparticles)and inoculated with small mycelial pellets;imp was cultured in solid medium and its spores were washed out with sterile distilled water for inoculation.Both M90 methods are available.The process of fermentation in a curved bed was adopted.The solid-state formulation of decomposing agent showed that among turf,rapeseed meal,bran and rice bran,turf was the most suitable carrier for solid-state agent of decomposing agent.The number of viable bacteria was the highest without preservative treatment,and the viable bacteria could still be detected after 90 days.The composting treatment was carried out by inoculating 1.4 kg decomposing agent into 200 kg tobacco stalk,which made the compost enter the high temperature period ahead of time and lasted longer.The temperature of the high temperature period reached 64.3? on the sixth day and 70.2? on the twelfth day during the composting fermentation process,which maintained the high temperature of 72-74? for three days.At the end of composting,the relative contents of cellulose,hemicellulose and lignocellulose in group T were 5.85%,5.40% and 14.13%,respectively.The degradation rate of lignin in group T was 56.78% higher than that in group CK,and the effect was remarkable.By promoting the degradation of lignocellulose biomass,the content of N,P and K in compost products of T group increased significantly than CK group.And the nicotine content in group T was significantly lower than that in group CK because the decomposition agent contained the nicotine-degrading strain P3 a.Mixed application of T-group tobacco stem bio-organic fertilizer and conventional chemical fertilizer to tobacco field was conducted to study soil physical and chemical properties and microbial flora under the application of organic fertilizer without tobacco stem organic fertilizer as control.The results showed that the application of tobacco stem bio-organic fertilizer in this experiment effectively increased the exchangeable calcium,available phosphorus and organic matter content in soil,and effectively maintained the soil acid-alkali balance.Based on the absolute group abundance,the calculation showed that the application of bio-organic fertilizer significantly increased the bacterial community abundance and inhibited the fungal community.The abundances of 6 pathogenic microorganisms,12 beneficial microorganisms and 15 antagonistic microorganisms were calculated.The application of organic fertilizer significantly reduced the pathogenic microorganism abundance and increased the abundances of most beneficial microorganisms and antagonistic microorganisms.In this study,microorganisms degrade lignocellulose in tobacco stalks were screened and compounded to tobacco stalk maturing microbial agent,which were added to the composting treatment of tobacco stalks to investigate its effect on tobacco stalk maturity.Finally,the composting product was applied to tobacco fields to evaluate its effect and to study its effects on tobacco agronomic properties,soil physical and chemical properties and microbial flora.This study is significant for accelerating tobacco composting process,improving tobacco utilization rate and developing high-quality tobacco bio-organic fertilizer.