Preliminary Exploration On The Effect Of Intercropping Festuca Elata And Trifolium Repens On The Citrus Orchard Ecosystem

Citrus is the largest fruit crop in the world,as well as in China.There are many kinds of weeds in citrus orchard,which seriously harm the growth and development of fruit trees and affect the yield and quality of citrus.To explore efficient and green weeds control measures in citrus orchard,in this study,the control effect of Festuca elata and Trifolium repens on weeds in citrus orchard was evaluated.The effects of different control measures of inter-rows weeds on arthropod communities,soil physicochemical properties,soil microorganisms and citrus quality in citrus orchard were preliminarily explored.And herbicides that are safe for F.elata and T.repens were screened.The results will provide theoretical basis for the scientific control of weeds in citrus orchard.1.Intercropping F.elata and T.repens can control weeds in citrus orchard.After 131,222 and 277 days of sowing plants,F.elata controled 53%,94% and 83% of inter-rows weeds,respectively,and the control efficacy of T.repens were 66%,97% and 89%,respectively.2.Different control measures of inter-rows weeds in citrus orchard have no significant effect on the stability of arthropod communities.Compared with chemical control and artificial weeding,intercropping F.elata and T.repens significantly increased the diversity of arthropod communities in citrus orchard.The results of sub-communities analysis of arthropod communities showed intercropping significantly reduced the number of herbivorous group of arthropods such as Panonychus citri and Leptocorisa chinensis.Moreover,during the outbreak of herbivorous arthropods such as Phyllocnistis citrella and P.citri,intercropping significantly increased the number of predatory group(Araneida,Syrphidae,etc).3.Compared with chemical control and CK,intercropping F.elata and T.repens in citrus orchard significantly improved the content of available potassium and alkaline nitrogen in the soil.Furthermore,intercropping F.elata also significantly improved soil organic matter and p H.The results of soil microbial high-throughput amplicon sequencing in citrus orchard showed glufosinate ammonium treatment significantly reduced the diversity of soil fungi.Compared with other treatments,there was a significant improvement in the relative abundance of the Didymellaceae-unidentified and Alternaria in the glufosinate ammonium treated area,and most of the fungi in these two genera are plant pathogenic microorganisms.There were no significant differences in bacterial diversity between different control measures of inter-rows weeds in citrus orchard.Compared with chemical control,intercropping T.repens significantly improved the relative abundance of phylum Chloroflexi bacteria associated with the N and S cycles of FCPS473 and KD4-96,while intercropping the F.elata significantly improved the relative abundance of Solibacter associated with nutrient cycling.4.Intercropping F.elata and T.repens in citrus orchard significantly improved the soluble solids content and solid acid ratio of the fruit.And it also improved the Vc content of the fruit compared with glufosinate-ammonium treatment and CK.5.The herbicide safety experiments on F.elata and T.repens were measured.Results showed that there were no significant effect on the growth of F.elata after treatmented with80.5 g/L fenoxaprop-P-ethyl EC,40% MCPA-sodium WP,48% bentazone AS,and 44%MCPA-isooctyl·florasulam·topramezone SC at the recommened field dose.And there was no significant effect on the growth of T.repens after treatmented with 8.8% quizalofop-Pethyl EC.