Effects of Different Grass Cultivations on the Soil Fertility and Fruit Quality of Sweet Orange Pomelo in Orchards

In order to understand the effects of different grass cultivation on the orchard soil environment and fruit quality of sweet orange pomelo, by taking the clean cultivation as the control group, six treatments of Vulpiamyuros, Brassica campestris, Lolium multiflorum, Astragalus sinicus, Medicago falcata and Vicia sativa were set up in the field to conduct the experiment of grass cultivation. Then, the soil and fruit samples were collected and analyzed. The results showed that compared with the clean cultivation, the pH value of soil in orchards increased by 12.2% and 8.1% after planting Brassica campestris and Vicia sativa, and the difference reached significant level (P<0.05). The contents of soil available nitrogen, available phosphorus and rapid available potassium in the six treatments of grass cultivation increased by 32.2%-50.7%, 31.3%-50.0% and 35.9%-49.4% (P<0.05). The contents of soil organic carbon, microbial biomass carbon, water-soluble organic carbon and water-soluble organic nitrogen also increased significantly by 20.3%- 31.2%, 21.4%- 48.4%, 21.7%-58.4% and 24.8%-36.0% (P<0.05). The activities of soil protease, sucrose enzyme and urease were significantly increased by 23.1%-84.6%, 22.2%-42.5% and 27.6%-62.1% (P<0.05). The yield and fruit quality of sweet orange pomelo were improved to a certain extent by grass cultivation, but there was no significant difference between the grass cultivation and clean cultivation (P>0.05). In summary, the grass cultivation improved the environment of soil in orchards and could be promoted and applied in the production of sweet orange pomelo.