Effects of Chemical Fertilizer Reduction and Application of Organic Fertilizer on Growth and Rhizosphere Microorganisms of Litchi

Abstract

【Objective】In regard to the problems including excessive chemical fertilizer application and serious soil quality decline in litchi orchards in Guangdong Province, and the urgent need of resource utilization of manure produced by the surrounding large-scale livestock and poultry breeding, the effects of fertilizer reduction combined with organic fertilizer on growth and rhizosphere microorganisms of litchi were studied, aiming to provide fertilization references for the scientific planting of litchi in Guangdong Province.【Method】'Guiwei' litchi was used as the research material. Six treatments were set: no fertilization (CK), chemical fertilizer application (CF), fertilizer reduction by 30%, and combined application of pig manure organic fertilizer of 5 kg/plant (OF5), 10 kg/plant (OF10), 15 kg/plant (OF15), and 20 kg/plant (OF20). The relative indicators of enzyme activity of litchi rhizosphere soil, number of culturable microorganisms, microbial biomass, yield and quality under different treatments were compared.【Result】The results showed that compared with the CF treatment, when the chemical fertilizer application was reduced by 30%; Under the OF15 treatment, the invertase activity and urease activity of rhizosphere soil were increased by 35.3% and 25.6%, the number of actinomyces increased by 18.1%, and the microbial biomass nitrogen increased by 23.6%; Under the OF10 treatment, the phosphatase activity was increased by 32.2%, the number of fungi increased by 14.4%, the microbial biomass carbon increased by 26.1%; Under OF20 treatment, the number of culturable bacteria was increased by 11.8%. The application of organic fertilizer could significantly improve the quality and yield of litchi. Compared with the single application of chemical fertilizer, the yields under OF5, OF10, OF15 and OF20 treatments increased by 7.15%, 10.64%, 13.75% and 13.32%, respectively.【Conclusion】In conclusion, the application of 10kg-15kg pig manure organic fertilizer with chemical fertilizer reduced by 30% could significantly improve the quality and efficiency.

Keywords

• chemical fertilizer reduction
• litchi
• rhizosphere microorganism
• organic fertilizer
• enzymatic activity
• yield