Effects of Different Fertilization Treatments on Walnut Yield, Quality and Soil Fertility

Taking the walnut 'Xiangling' as the research object, 5 fertilization tests includes no fertilizer(CK), single application of chemical fertilizer(F), chemical fertilizer and organic fertilizer(F+M), chemical fertilizer and biological organic fertilizer(F+B), chemical fertilizer, organic fertilizer and biological organic fertilizer(F+M+B), through analysis of walnut yield and quality, soil fertility and microbial quantity to different fertilization treatments. The findings indicated that with the extension of the fertilization period, the yield of walnut increases year by year, and chemical fertilizer, organic fertilizer and biological organic fertilizer treatment had the highest yield increase rate, up to 101%. Combined application of organic fertilizers can also improve the quality of walnuts and the chemical fertilizer, organic fertilizer and biological organic fertilizer treatment had the best effect. The content of protein, glutamic acid, unsaturated fatty acid, trace element Zn and Fe are 18.0%, 3.65%, 93.1%, 225.1 mg/kg and 34.9 mg/kg respectively. The trend of soil moisture content, available nitrogen, phosphorus, potassium content and soil microbial quantity among different fertilizer ratios are chemical fertilizer, organic fertilizer and biological organic fertilizer > chemical fertilizer and biological organic fertilizer > chemical fertilizer and organic fertilizer > single application of chemical fertilizer > no fertilizer. The mixed application of chemical fertilizers, organic fertilizers and bio-organic fertilizers has the best effect, which can significantly improve the yield and quality of walnuts, increase soil fertility, and meet the goals of high yield, stable yield, high quality and sustainable development.