Biological Effects Of Trichoderma Bio-Organic Fertilizer On Plants In Coastal Saline Soil

The area of coastal saline soils is recognized as an important land resource with utilization value for agriculture in China.Jiangsu has 687 3000 ha coastal saline mudflat that occupies ca.25% of the coastal saline area of the whole country.However,the coastal mudflat is usually characterized by poor plant growth and low microbial activity due to its high salinity suppressing most crops via the high osmotic stress,nutrient deficiency,toxicity,and poor physical soil conditions.Soil microbes like Trichoderma spp.play a significant role in assisting plants to tolerate salinity stress.The present study aimed to investigate the biological effects of two Trichoderma strains(T.arenarium 1A131,which was isolated from the local Dafeng coastal saline soil;and T.guizhouense NJAU 4742,which has been commercially utilized in China)and their bio-organic fertilizers on tomoto and cabbages grown in coastal saline soil as well as their effect on soil nutrient availabilities and soil fungal community.The main results obtained were summarized as below:1)In the sand cultivation experiment,60% Trichoderma bio-organic fertilizer + 40%chemical fertilizer treatment significantly(P< 0.05)increased the plant biomass and root growth of cabbage and tomato,compared to the control without fertilization(CON)and the chmical fertilization one(CF).Specifically,the biomass and root of cabbage increased by34.8% and 273%,respectively,and the biomass and root growth of tomato increased by44.3% and 79.2%,respectively.The nutriention of the plant was also significangly improved.There was no significant difference(P> 0.05)between the effect of T.guizhouense NJAU 4742 bio-organic fertilizer and T.arenarium 1A131 bio-organic fertilizer on plant growth in this condition.2)In the pot soil experiment(the soil was collected from the coastal area of Dafeng,Jiangsu),60% Trichoderma bio-organic fertilizer + 40% chemical fertilizer treatment significantly(P< 0.05)improved the soil environment of the coastal saline soil,compared to the control CON and the CF treatment.The content of organic matter in the soil increased,and the growth of the plant of tomato was significangly promoted by the application of such certain bio-organic fertilizer.The plant-growth promoting effect of T.arenarium 1A131 bio-organic fertilizer was slightly but still significangly(P< 0.05)better than that of the T.guizhousense NJAU 4742.More importantly,the results showed that60% organic fertilizer coped with 40% chemical fertilizer was the best optimized fertilization regime that may be suitable for application in saline agriculture in such coastal area,which however needs further test.3)The results of ITS amplicon sequencing via Miseq showed that 60% bio-organic fertilizer plus chemical fertilizer significantly(P< 0.05)increased the diversity and species richness of the fungal community,and effectively enriched plant-beneficial fungi to tomato roots.Thus,the application of this fertilization combination not only improved the soil available nutrients,but also significangly and positively effectted the fungal microbiome in coastal saline soil.