Scientific Assessment Of The Technology Of In-situ Cucumber/Tomato Residue Return In The Greenhouse

The tremendous scale of protected vegetable cultivation incidentally produces considerable vegetable residues,which refers to the remaining parts of plants after the final harvest.Vegetable residues are rich in mineral elements and organic matter.But the utilization of vegetable residues has the problems of labor-consuming,time-consuming,and low resource utilization.Recently,the risk of carrying detrimental pathogens has been markedly reduced by effective preventive measures coping with diseases and insect pests during the whole cultivation process.Also,with the continuous improvement of cultivation technology and the development of pest control technology and small returning machinery,the technology of in-situ vegetable residue return in the solar greenhouse is being widely popularized and applied.However,there was few systematic studies on the scientific of continuous in-situ vegetable residue return on protected facility.Therefore,we put forward fruit vegetable residues directly returned to the soil for five times and investigated its effects on soil physicochemical characteristics,soil microbial communities,plant growth,and yield with the cucumber-tomato rotation pattern.This paper could expound the scientific of in-situ fruit vegetable residue return in the greenhouse.And this experiment could develop a feasible and economic technique for the use of fruit vegetable residues.The main results of this study are as follows:1.In-situ cucumber/tomato residue return increased the soil alkali-hydrolysed nitrogen and available potassium contents,for 4.97%-26.22%and 9.31%-21.92%,respectively;along with slightly reduced soil p H for 0.07-0.39 unit,and bulk density for 6.72%-11.81%.So,in-situ cucumber/tomato residue return could improve soil structure and soil fertility.2.Soil microbial communities was determined after five times in-situ cucumber/tomato residue return.Residue return increased the relative abundance of Gemmatimonadetes,Planctomycetes,Saccharibacteria and Basidiomycota,for 39.12%,48.48%,166.67%,and 236.84%,respectively,and decreased the relative abundance of Firmicutes and Mortierellomycota,for 45.08%and 57.01%,respectively.Gemmatimonadetes,Gemmatimonadeles,Cephaliophora,and Cephaliophora-tropica were the predominant microbial.And in-situ cucumber/tomato residue return did not influence the relative abundance of pathogenic microbes.3.The correlationships between soil microbial communities and soil physicochemical characteristics were determined after the five times in-situ cucumber/tomato residue return.Soil alkali-hydrolysed nitrogen and total potassium were the prime factor driving the variation in bacterial and fungial communities,respectively.Soil alkali-hydrolysed nitrogen was closely correlated with the abundances of the bacterial phyla Gemmatimonadetes and Saccharibacteria.Soil total potassium was positively correlated with Basidiomycota.4.When the appropriate precautionary measures were taken,in-situ residue return did not aggravate the occurrence of cucumber/tomato diseases,such as fusarium wilt,root knot nematode disease,and so on.Residue return,performed three to five times,increased the fruit yield,for 8.24%,7.53%,and 8.27%,respectively.And the increased fruit yield brought about additional profits of 35.1thousand RMB·ha^-1,38.3 thousand RMB·ha^-1,and 55.6 thousand RMB·ha^-1.Compared with manual removal cucumber/tomato residue,in-situ residue return could cut down the disposal expense of fruit vegetable residues by 3150 RMB·ha^-1.In conclusion,under the appropriate precautionary measures,in-situ residue return did not aggravate the occurrence of cucumber/tomato diseases.And residue return could not only improve soil physicochemical characteristics,but also affected the microbial communities,greatly contributed to the increase of fruit yield,decrease of the input of residue removal,and the increase of additional profits.Also,in-situ residue return could reduce the usage of fertilizer and cut down the environmental pressure.In a word,in-situ fruit vegetable residue return is a green,healthy,sustainable,and simplified resource utilization technique.And the technology of in-situ fruit vegetable residue return has a wide application prospect.