Plant Growth Promotion Effect Of Two Trichoderma Strains And Their Bio-organic Fertilizers

In some areas of China,there are serious problems in the application of chemical fertilizers,which resulted into a huge waste of chemical fertilizer resources,increased agricultural costs and reduced the income of farmers.Application of bio-organic fertilizer increases soil biomass,activates soil microbiome and increases availability of soil nutrients.The organic matter provides a large amount of food resources for the beneficial microorganisms,and the beneficial microorganisms promote the maturity of the organic fertilizer.Once the two are combined in fertilization,they promote and complement each other,and utilize each other to improve the porosity,permeability and water retention of soil,and enhance the nutrient absorption capacity of the root system.Increasing the amount of fertilizer use effeciency,thereby,can reduce the amount of chemical fertilizer application rates.Therefore,the replacement of chemical fertilizer by organic fertilizers or bio-organic fertilizers is the necessary for developing sustainable agriculture.This combined use of bio-organic fertilizers with reduced amount of chemical fertilizers is of great significancefor saving farming costs,improving agricultural product quality and protecting environment.In the screening of a multiple functional Trichoderma strian,tests regarding plant growth-promoting ability,sporulation ability,salt-tolerant ability and antagonism(against several phytopathogens)ability were performed;then the selected strains were continued with pot and field experiments of water spinach and cucumber,using no fertilizer(CK)and full rate of chemical fertilizer application(CF)as control.The results derived are as follows:1)In the test of screening for the high-efficient Trichoderma strain:different Trichoderma strains showed different effects on pathogens.For inhibiting of Fusarium oxysporum(Foc4),1680>NJAU 4742,for another F.oxysporum(Foc),T1>NJAU 4742,for F.graminearum(Ft),1680>T1>NJAU 4742,for Alternaria alternate(Alt),T1>916>NJAU 4742;for salt resistance capacity,1680>917>NJAU 4742>T1;for sporulation ability,T1>916>1680>NJAU 4742;among them,NJAU 4742 showed the highest plant growth promoting ability on tomato seedlings under greenhouse conditions.Thus,Trichoderma NJAU 4742 and T1 were selected for further studies.2)The application of Trichoderma bio-organic fertilizer plus 25%～75%rate of conventional chemical fertilizers significantly(p<0.05)increased the yield and quality of water spinach,soil organic matter and nutrient availability.In the field experiment,the yield of water spinach X1,X2,Y1,Y2(ie,fresh weight in the shoots)was significantly higher than other treatments,and the protein content of water spinach treated with X2,Y1,Y2,Y3,X3 and X1 was significantly higher than that in the field.CF and CK,relative to CF,X1,X2,X3,Y1,Y2,Y3 were increased by 26%,46%,30%,44%,43%and 46%,respectively.In the pot experiment,compared to CF treatment,the yields of X1,X2,Y1 and Y2 were increased by 30.54%,28.19%,61%and 64%,respectively.The protein of Y1 and Y2 was increased by 25%and 24%,respectively.The content of vitamin C in plants increases with the proportion of bio-organic fertilizer application.The organic matter content of all treatments containing biological fertilizers X1,X2,X3,Y1,Y2,Y3 was significantly higher than that of non-fertilized control CK and chemical fertilizer treatment CF.Trichoderma T1 bio-organic fertilizer showed better plant-beneficial effect on water spinach than the effect of Trichoderma NJAU 4742 bio-organic fertilizer.3)Reducing the application of 25%of conventional chemical fertilizer and combined with a certain amount of bio-organic fertilizer can ensure the yield and quality of cucumber,compared with the full chemical fertilizer treatment,which also improved the soil bio-chemical properties.In the pot experiment,reducing the application of 25%chemical fertilizer combined with Trichoderma bio-organic fertilizer(X1 and Y1)was increased by 13%compared with CF treatment.In the field experiment,the application was reduced by 25%relative to CF.The content of vitamin C in chemical fertilizers combined with Trichoderma bio-organic fertilizer(X1 and Y1)increased by 19%and 9%,respectively.The increase of organic matter content also increased the soil microbial richness.Within a certain range,the effect of Trichoderma NJAU 4742 bio-organic fertilizer showed better plant-beneficial on cucumber than that of Trichoderma T1 bio-organic fertilizer.