Abstract:

The research aims to improve the soil quality, reduce the use of chemical fertilizer, and improve the yield and quality of lemon fruit by chemical fertilizer reduction combined with organic fertilizer application, thus to provide a technical basis for soil environment improvement and fertilizer reduction and efficiency increase in lemon plantations in Yunnan. We used ‘Yunning No.1’ as the test material and carried out a field plot experiment, four different fertilization treatments were set up, namely 100% chemical fertilizer(conventional fertilization), 70% chemical fertilizer (30% reduction)+15 kg/tree organic fertilizer, 50% chemical fertilizer (50% reduction)+15 kg/tree organic fertilizer and no chemical fertilizer+15 kg/tree organic fertilizer (control group), to measure relative indexes of lemon growth, bloom and fruit-setting, fruit quality, yield and chlorophyll content. The results showed that there were significant differences between 100% chemical fertilizer and 70% chemical fertilizer with organic fertilizer in plant height, stem diameter, yield and fruit quality. The treatment of 70% chemical fertilizer with organic fertilizer significantly promoted the plant growth, and achieved higher yield and quality. Compared with 100% chemical fertilizer, the plant height increased by 6.37%, stem diameter(up and down of the graft union 5 cm) increased by 13.05% and 9.61%, fruit weight and yield per plant increased by 15.19% and 28.60%, juice yield, vitamin C and total sugar content of lemon fruit increased by 6.68%, 27.85% and 6.20%, respectively. Comprehensively considering the yield and quality, the treatment has the best effect of yield increase, quality improvement and efficiency enhancement.

Key words: chemical fertilizer reduction, organic fertilizer, lemon, yield, quality