Effects Of Vermicompost From Food Waste On Soil Properties And Vegetable Growth And Quality

High intensity of chemical fertilizer and pesticide input and intensive cultivation mode in protected vegetables industry have led to a series of problems such as soil degradation,vegetables growth retardation,yield and quality decline and other problems.Organic substitution is an important measure to maintain soil health and sustainable development,which can significantly improve soil quality and promote crop growth and development.Vermicomposting from food waste is one of the important means of resource utilization.Vermicompost has better microbial active substances than common composting.In this study,three kinds of organic fertilizer including vermicompost from pig manure(PVF),vermicompost from food waste(PVF),organic manure(OMF),were used to replace 40%chemical fertilizer in greenhouse experiment under at the equal amount of nutrients,with chemical fertilizer(CF)and no fertilizer(CK)as control.The antioxidant properties and accumulation of micronutrients in vegetables,as well as the macronutrients,biological indexes and micronutrients in soil under the painting system of broccoli,green eggplant,Chinese cabbage and purple cabbage were determined.To explore whether vermicompost can replace conventional fertilization measures to improve vegetables crop growth and soil nutrient status.The main conclusions are as follows.The results showed that vermicompost had little effect on total nitrogen and total phosphorus,but had a better promotion effect on soil organic matter,available nutrients and biological properties: vermicompost significantly increased soil organic matter content(SOM)and soluble organic matter(DOC)content,and the promotion effect of meal residue vermicompost from food waste on soluble organic carbon was better than vermicompost from pig manure.In terms of available nutrients,the content of alkali hydrolyzable nitrogen(an)and available potassium(AK)increased by 6.13%～22.79% and 1.69%～30.17%,respectively,compared with chemical fertilizer application alone.Vermicompost replacement also significantly increased soil microbial biomass carbon and nitrogen(MBC,MBN),nitrogen and phosphorus cycling enzyme activities.Vermicompost could promote plant height and stem diameter of vegetables.Among the three kinds of organic fertilizers,vermicompost had the most significant effect on chlorophyll content(SPAD)of vegetables.The results showed that the application of organic fertilizer decreased MDA content and increased plant stress resistance by increasing POD and CAT activities in leaves.the application of organic fertilizer increased net photosynthetic rate of broccoli,Chinese cabbage and purple cabbage by increasing transpiration rate and stomatal conductance.The effect of vermicompost from food waste was better than that of vermicompost from pig manure and commercial organic fertilizer.There was no significant difference in the yield of vegetables crops under the treatment of replacement of organic fertilizer and chemical fertilizer,but it had a better effect on the quality of vegetables.Vermicompost from food waste could significantly increase the nutritional quality of vegetables,while Vermicompost from pig manure could significantly reduce the nitrate accumulation of vegetables.Vermicompost substitution had no significant effect on the total amount of soil micronutrients and the availability of Cu and Zn,but reduced the bioavailability of Mn and Fe in green eggplant and purple cabbage season.In the aspect of morphological transformation,vermicompost substitution promoted the content of reducible Fe,Mn and Zn in green eggplant season and the content of residual Zn and reducible Cu in red cabbage season.As for the accumulation of trace elements in vegetable crops,vermicompost replacing part of chemical fertilizer increased the accumulation of Fe,Cu and Zn in broccoli,Chinese cabbage and red cabbage,and increased the bioaccumulation factors of Mn and Fe in green eggplant and red cabbage.The results of principal component analysis and correlation analysis showed that the bioavailability of Mn and Fe was negatively correlated with soil p H,while the bioavailability of Cu and Zn was positively correlated with soil nutrients such as organic matter.The availability of micronutrients in fruits,Cu and Zn in soil had significant positive correlation with vegetable quality and photosynthesis.In conclusion,the substitution of vermicompost for chemical fertilizers can improve photosynthesis,antioxidant system and fruit quality of vegetable crops under the condition of ensuring yield,and promote the improvement of soil microbial activity through soil nutrients.In addition,vermicompost can improve the activity of soil microorganisms by increasing soil nutrients,and increase the content of reducible and residual trace elements in soil.However,in the process of fertilization,attention should be paid to the decrease of available Mn and Fe contents in soil.