The Effect Of Different Return Ways Of Vegetable Waste On Tomato Growth And Soil Environment

As people’s demand for better quality of life continues to rise,the area and variety of vegetables grown and their all-season supply have increased significantly,and so has the amount of vegetable waste produced with no commercial value.In the context of the national promotion of straw burning ban,it is imperative to guide the conversion of agricultural waste to resource-based return to landfill.In this paper,different amounts of tomato straw and kale leaf residues(1.8 t·667m^-2and 0.9 t·667m^-2)were returned to the field in an indoor soil culture trial,with and without the addition of fungicides（straw humicide and agricultural enzymes）,and soil temperature,p H,EC,organic carbon,nutrient content and humus components were measured at 7,14,21,28 and 35 d after return to the field.The effect of the fungicide application and the amount of return to the field on the decomposition of vegetable waste was investigated.In addition,the tomato straw was returned to the field after composting and directly to the field according to the above-mentioned suitable amount of return and the selected fungicides through pot experiments to study the effects of different return methods on soil physicochemical properties,soil enzyme activity,bacterial community,as well as tomato growth and physiological indicators were studied,with a view to providing a theoretical and practical basis for the resource utilization of vegetable waste.The main findings are as follows:1.In indoor soil culture trials,the organic carbon content of all treatments increased rapidly from 0.55 to 1.73 g·kg^-1at 7 d.Compared with the non-fungicide treatments,the total N,available N and available K contents of tomato straw full returned to the field with enzymes increased by 14.49%,9.30%and 5.61%respectively after 35 d,and the available phosphorus content of full return of kale leaves with enzymes to the field increased the most,reaching 34.98%.During the direct return of vegetable waste to the field,the soil water soluble substance carbon content of tomato straw reached its maximum at day 21,while that of kale leaf residue rose to its maximum at day 7,and the soil water soluble substance carbon content of all kale leaf residue treatments was overall higher than that of tomato straw.The full return of vegetable waste with enzymes effectively promoted the increase of soil humus and huminic acid content,and the degree of soil humification in both vegetable waste return treatments reached the maximum at the 7th day of return.2.During the pot trial,the tomato straw return treatments were effective in increasing soil nutrient content and soil enzyme activity,with the largest increases occurring in the straw return treatments alone and with enzymes.At 73 d of tomato growth,there was no significant difference in soil bulk and porosity between the treatments and the conventional fertiliser treatment.Bacterial community diversity increased to different degrees in all treatments during tomato growth,and straw composting and enzyme addition to the field increased bacterial community richness,but soil species richness decreased in the control and direct straw return treatments.The relative abundance of Proteobacteria,Actinobacteriota and Firmicutes in the soil of each treatment was high and dominated absolutely,among which Proteobacteria and Firmicutes were closely related to the physicochemical properties of the soil.3.In the 73 d pot trial,the different straw returns increased tomato plant height,stem thickness,above-and below-ground dry weight,total dry weight,fruit weight and yield per plant,but the chlorophyll content of each component was significantly lower in the straw return treatment alone than in the control at 34 d.From the root vigor of tomatoes in each treatment,straw with enzyme application could induce an increase in plant root vigor.4.A comprehensive analysis of soil properties and tomato growth and physiological indicators showed that the vegetable waste returned to the field could promote crop growth and improve the soil environment in the root zone under the conditions of this experiment,with the best effect of 1.8 t·667m^-2of vegetable waste with enzyme application.