减施氮肥对富士苹果园土壤养分及酶活性的影响

Effects of reduced nitrogen application on soil nutrient and enzyme activities in Fuji apple orchard

【目的】以20 a树龄的富士苹果树为试验对象,研究减少氮肥,配合施用微生物菌肥对富士苹果园土壤养分及微生物活性的影响。【方法】试验设置传统施肥(CK)、减少施氮10%(T_(1))、20%(T_(2))、30%(T_(3))和40%(T_(4)),配合施用8 kg/棵的微生物菌肥5种试验处理,以传统施肥为对照CK,分析富士苹果园土壤的全氮、全磷、全钾、速效氮、速效磷、速效钾和有机质含量等土壤肥力指标,土壤蛋白酶、蔗糖酶、脲酶和碱性磷酸酶等土壤微生物活性指标,并对土壤肥力指标和微生物活性指标进行相关性分析。【结果】所有处理的土壤含水率和土壤养分,20~40 cm的土层深度比0~20 cm土层高,其中T_(2)和T4 0~20 cm的土层深度明显高于CK的土壤含水率高,所有处理20~40 cm的土层深度土壤含水率低于CK;所有处理的土壤养分,0~20 cm土层深度比20~40 cm高。0~20 cm和20~40 cm的土壤全氮含量、全磷含量、全钾含量、速效氮含量、有效磷含量和速效钾含量以T_(2)最高。所有处理0~20 cm和20~40 cm土层深度的土壤有机质含量和pH以T_(2)最高,且显著高于对照CK。T_(2)处理苹果园的土壤蛋白酶和蔗糖酶含量最高,所有处理的富士苹果园土壤脲酶和碱性磷酸酶含量均比CK高,T_(2)处理富士苹果园土壤脲酶和碱性磷酸酶含量最高。【结论】在本研究区域内减氮20%配施8 kg/棵的微生物菌肥的肥效最佳。

【Objective】With the 20-year-old apple trees employed,this study was conducted to investigate the impact of reducing nitrogen fertilizer in conjunction with microbial fertilizer application on soil nutrients and microbial activities in Fuji apple orchard.【Method】The five experimental treatments treatments of traditional application and reducing nitrogen application by 10%,20%,30%and 40%,combined with microbial fertilizer application of 8 kg/tree,with traditional fertilization serving as the control(CK).Soil fertility parameters such as total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus,available potassium,and organic matter content in the Fuji apple orchard soil were analyzed.Soil microbial activity indicators including soil protease,urease,and alkaline phosphatase were assessed,with a correlation analysis conducted between soil fertility parameters and microbial activities in the Fuji apple orchard.【Result】Soil moisture and nutrient levels in the 20~40 cm soil depth surpassed those in the 0~20 cm soil layer,with significantly higher levels observed in the 0~20 cm layer in treatments T_(2) and T4 compared to CK,while moisture content in the 20~40 cm layer was lower than in CK.Across all treated soil nutrients,the 0~20 cm depth exhibited higher levels than the 20~40 cm depth.The highest concentrations of total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus,and available potassium were found in both the 0~20 cm and 20~40 cm soils in treatment T_(2).Soil organic matter content and pH were highest in the 0~20 cm and 20~40 cm soil depths in T_(2),significantly exceeding CK.Protease and sucrase contents in the Fuji apple orchard soil were highest in treatment T_(2),while urease and alkaline phosphatase levels were elevated in all treated soils compared to CK,with T_(2) exhibiting the highest levels.【Conclusion】The treatment T_(2),i.e.,the 20%reduction in nitrogen combined with 8 kg/tree of microbial fertilizer,demonstrated the most favorable effects of fertilizing.