Grass and Plastic Film Mulching Pattern Improve Soil Organic Carbon Pool, Physical Properties, Fertility and Fruit Quality of Ponkan Orchards

Abstract Aims: Special fertilizer and soil mulching have been used to improve crop yield worldwide. However, the effects of special fertilizer with mulching on soil characteristics of citrus orchards were not yet fully understood. This study aimed at assessing the effects of different mulch patterns including plastic mulching and grass mulching on improving fruit quality of Ponkan and providing a new insight of mulching development in citrus orchards.Methods: In this study, a two-year field experiment was conducted to investigate the effects of citrus special fertilizer (FR), grass mulching (RGM), and plastic mulching (RPM) on fruit quality, soil organic carbon fractions, physicochemical properties, and plant nutrition in Ponkan citrus orchard.Results: The study resulted showed that special fertilizer treatment and grass mulching treatment increased Total soluble solid contents by 6.76% and 3.97%, while plastic mulching decreased Titratable acid contents by 19.44%, resulting in increases of fruit TSS: TA by 6.14%, 3.61%, and 22.76%, respectively. Correlation analyses showed that citrus fruit quality was associated with soil bulk density, Total porosity, Capillary porosit, Aeration porosity, Total organic carbon, Readily oxidized organic carbon, Microbial biomass carbon and Soil available phosphorus. Soil physical properties were improved by RPM, but FR and RGM had better effects on soil nutrients and organic carbon, as evidenced by the results of principal component analysis and loading matrix plot. Conclusions: This study suggested that the different effects of special fertilizer, plastic mulching, and grass mulching on improving fruit quality were associated with their diverse effects on improving soil characteristics.