| Malus pumila ‘Nagafu 2’ is one of the main varieties of apple orchards in southern Xinjiang basin. But the long period of the clean tillage makes the soil preserve moisture and fertility of the orchard to become weak, and then affect the quality and yield of fruit. In this study, apple orchard covered with grass(orchard Ⅰ) and the clean tillage apple orchard(orchard Ⅱ) was taken as the test sample plot. The differences of climatic factors, soil physical and chemical properties and the growth of apple trees in two orchards were compared by regression analysis, the regression equation between biomass and physical properties, soil elements and fruit quality of orchard was established. To reveal the positive effect of natural grass on improving the ecological environment and improving the quality of the orchard, and to provide theoretical basis and technical guidance for the land management of apple orchard. The main results were as follows:The daily temperature changes of orchard Ⅰ and orchard Ⅱ showed a single peak curve, and monthly variation showed a trend of first increased and then decreased. Diurnal variation of relative humidity in this two orchards were opposite to air temperature change, monthly variation of relative humidity was decreased and then rising. The change of soil temperature in different depth from top to bottom were gradually decreased, the temperature of the orchard Ⅰ lower than the orchard Ⅱ, but the relative humidity was higher than orchard Ⅱ,and the soil temperature of different depths was lower than the orchard Ⅱ at the same time.The difference of soil bulk density and field moisture capacity in two kinds of orchards of different years was significant: the soil bulk density of the grass growing orchard was significantly decreased, and the water content in the field was increased obviously, and the change was more obvious with the increase of the grass growing period. But there has been no significant change in the orchard Ⅱ. The effect of grass on soil water content was the most obvious when the grass height was 30 cm and 40 cm.The macroelement and microelement of different soil depth were significantly different in two kinds of orchards of different years. The contents of OM, AK, AN and other elements in orchard Ⅰ were higher than that of orchard Ⅱ, and increasing the planting grass year added the differences between them. The effect of natural grass on the soil layer of 0~20 cm was most obvious, it will gradually extend to deeper soil with the increase of the grass growing period. And the SQI index of orchard Ⅰ of different ages was higher than that in the same period of orchard Ⅱ.The yield of apple trees in two orchards was concentrated in the middle and the middle layer of the canopy, the peripheral fruit pericarp firmness, fruit weight, soluble solids, reducing sugar and soluble sugar of apple in the canopy lower to upper,inside the chamber to the outside showed gradually increasing law, but the titration acid and p H value showed the opposite trend, and the change trend of fruit shape index and Vc content was not obvious. The height, crown width and stem diameter of apple trees in the orchard Ⅰ were greater than orchard Ⅱ, as did the yield per plant and quality index of apple.The optimum biomass values of ecological environment and fruit quality in orchard Ⅰ were obtained by regression analysis, the suitable biomass of soil bulk density, soil moisture content, field water holding capacity and temperature and humidity was in 0.548~0.020, and TN, AK, Ca and other elements in soil was in 0.144~0.018, and the fruit quality was in 0.434 ~ 0.518.Biomass and fruit most orchards ecological factors and quality factors are established R2 and F value significant or highly significant quadratic regression equation... |
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