攀西芒果园土壤pH与有效养分的相关性研究

采集攀西芒果主产区果园土壤样本42个，探讨土壤pH、有效养分状况及两者的相关性。结果表明，攀西芒果园土壤pH变化范围为4.8~8.4，中性、酸性土壤占76.2%。果园土壤有机质、碱解氮、交换性钙和有效锌表现为严重缺乏状态，有效铜和硼整体处于低水平，有效钾含量为中下水平，而有效磷、交换性镁、有效硫、有效铁和有效锰5种元素的含量表现较为丰富。果园土壤pH和大部分有效养分存在显著的相关性，土壤pH与有机质、碱解氮、有效钾、有效铜、有效锌、有效铁、有效锰呈极显著负相关，与交换性钙、有效硫呈极显著正相关，而与有效性磷、有效硼、有效钼的相关性则不显著。从三种函数类型的回归分析来看，土壤pH与有机质关系符合幂函数，与碱解氮、有效锌、有效硫呈线性相关，与有效钾、交换性钙、有效铜、有效铁、有效锰则符合指数函数，而与交换性镁则符合二次函数，各相关系数均达极显著水平。总体上，土壤pH在中性偏酸的范围内，养分相对较为平衡，pH过酸或过碱，都容易造成养分的失衡，因此土壤pH过酸的果园，应注意适量施用石灰或含钙镁的肥料，与之相反，碱性土壤则应避免再次施用石灰或碱性肥料。

Correlation between Soil pH and the Contents of Available Nutrients in Selected Soils from Mango Orchards in Panxi

Soil samples (42) were collected in Panxi mango orchards to evaluate the correlation between soil pH and available nutrients. Results revealed that the mango orchards soil pH range were 4.8~8.4, neutral and acidic soils accounted for 76.2%. The contents of soil organic matter, available nitrogen, zinc and exchangeable calcium were serious lack, available copper and boron were low, available potassium was middle level, available phosphorus, sulfur, iron, manganese and exchangeable magnesium were rich. There were significant correlation between soil pH and most of available nutrients. The soil pH value showed a high significant negative correlation with the contents of soil organic matter, available nitrogen, potassium, copper, zinc, iron and manganese, and a high significant positive correlation with available sulfur, exchangeable calcium, and no correlation with available phosphorus, boron and molybdenum. Aim at soil pH and available nutrients, 3 kinds regression analysis were done and a conclusion was draw that it accorded with power function between soil pH and organic matter, linear function between soil pH and available nitrogen, zinc, sulfur, exponential function between soil pH and available potassium, copper, iron, manganese, and quadratic function between soil pH and exchangeable magnesium. Conclusively, the nutrients were relative balance in neutral and weak acid soils, and were imbalance in over acidic and alkaline soils. The results further suggested that in over acidic soil of orchard, use of lime and ca-mg fertilizers should be done, but use of lime and alkaline fertilizers should be avoided in alkaline soil.