Effects Of Different Habitats On Soil Characteristics And Watermelon Growth And Development

The rapid development of vegetable industry in China has played an important role in promoting regional economic development and stable agricultural development.However,the sustainable development of vegetable industry in facilities is severely restricted by single habitat,disappearance of restriction relationship between organisms in facilities,soil degradation and environmental pollution caused by excessive fertilizer application.In this study,the effects of different habitats on soil physical and chemical properties and fruit quality of greenhouse vegetables were analyzed through the combination of biochar,earthworm manure,earthworm in situ and Trifolium repens,so as to provide theoretical basis for the healthy ecological production of greenhouse vegetables in Ningxia and similar areas.Taking "Huiling" watermelon as the research object,12 treatments were set up:Blank control(T1);Biochar(T2);Clover(T3);Clover+earthworm in situ(T4);Biochar+earthworm in situ(T5);Clover+biochar(T6);Clover+biochar+earthworm in situ(T7);Earthworm in situ(T8);Vermicompost+earthworm in situ(T9);Vermicompost+biochar+earthworm in situ(T10);Vermicompost+clover+earthworm in situ(T11);Vermicompost+biochar+clover+earthworm in situ(T12);The application amount of biochar was 6546.64kg·hm-2,and clover seeding was adopted.The results are as follows:(1)The soil temperature was the highest at 5 cm,and decreased with the increase of soil depth,and the range of soil temperature decreased with the increase of soil depth.Cloverleaf mulching reduced soil temperature,and the in situ treatment with cloverleaf mulching and earthworm was the best.Biochar treatment decreased soil pH and increased soil urease activity(P<0.05).Soil EC value was decreased by covering clover(P<0.05).Earthworm manure+biochar+cloverleaf+earthworm in situ treatment increased soil total nitrogen 184.78%,available nitrogen 279.74%,available potassium 196.80%,and soil phosphatase activity(P<0.05).Soil total P and available P were increased by 108.64%and 98.55%by earthworm manure+cloverleaf mulching+earthworm in situ treatment.Soil organic matter was increased by 221.41%by vermicompost+earthworm in situ treatment.Soil sucrase activity was increased by cloverleaf mulching and earthworm in situ treatment(P<0.05).Biochar+earthworm in situ treatment increased the diversity of soil bacterial community,vermicompost+cloverleaf+earthworm in situ treatment increased the dominance of soil bacterial community species,and biochar treatment increased the richness of soil bacterial community species.In situ treatment of earthworms increased the diversity of soil fungal community,vermicompost+vermicompost increased the species dominance of soil fungal community,and vermicompost+cloverleaf+vermicompost increased the species richness of soil fungal community.(2)The transpiration rate and intercellular CO2 concentration of watermelon were increased by cloverleaf mulching and earthworm in situ treatment,while the net photosynthetic rate and stomatal conductance were increased by earthworm in situ treatment.Wormcast+biochar+cover clover+earthworms in situ treatment improves the total nitrogen content of root and rhizome of leaves and total phosphorus,total potassium content(p<0.05),earthworm manure+biochar+earthworms in situ treatment to improve the total nitrogen content of stem(p<0.05),covering the clover+biochar+earthworms in situ treatment improved the leaf total nitrogen content(p<0.05).Vermicompost+biochar+cloverleaf+earthworm in situ treatment increased plant biomass(P<0.05).Vermicompost+biochar+earthworm in situ treatment increased soluble solid matter by 12.03%,vermicompost+biochar+cloverleaf+earthworm in situ treatment increased soluble sugar content by 59.28%,cloverleaf+earthworm in situ treatment decreased organic acid content.A total of 918 metabolites were detected by LC-MS analysis,and 8 different metabolites were screened,including vitamins and coenzyme factors,steroids,peptides,organic acids,nucleic acids,lipids,hormones and transfer media,and carbohydrates.The up-regulation of prostaglandin PGE21 1-triglyceride content was the most significant.The content of vermicompost+biochar+cloverleaf+earthworm in situ treatment was the highest,34.85 times that of the control.Compared with the control,the yield of watermelon was increased by 42.36%,reaching 7630.65kg·667m-2 by vermicompost+cloverleaf+earthworm in situ treatment.Through principal component analysis of soil nutrients,soil enzyme activity,growth index,quality index and yield index of watermelon,and comprehensive score ranking,it is concluded that vermicompost+biochar+clover+earthworm in situ treatment is the best comprehensive evaluation of this study.