N素施用量对冬枣园不同时期土壤化学特性及其营养的影响
The Effect of Nitrogen Application Rate on Soil Hemical Properties and Nutrition in Different Periods of Dongzao Garden

为了了解N素对园地各个物候期土壤化学性质及其营养的影响，以天津静海冬枣园为基地，通过单因素随机区组设计，进行了不同时期、不同N素施用量处理。结果显示：高氮量处理使土壤pH值提升3.44%，含盐量降低5.35%，有机质增加16.89%，速效N增加83.83%，速效P降低33.84%。总之，碱地枣园土壤施氮增加了土壤中有机质、速效氮、速效钾的含量，降低了土壤含盐量。但是，增加了土壤pH，降低了速效磷。施加N素越多，土壤pH值、有机质、速效氮越大；高量氮会降低土壤速效钾。各物候期中，萌芽期有机质和速效P含量最高，开花期pH、含盐量最高，坐果期速效N和K最高；开花期速效N最低，幼果期含盐量、pH值和有机质最低，果实成熟期速效P最低，采果后速效K最低。
In order to understand the effect of Nitrogen on the chemical properties and nutrition of the soil in each phenological phase of the garden, Tianjin Jinghai Winter Jujube Garden was used as a base and a single-factor random block design was used to treat different periods and different amounts of Nitrogen application. The results showed that the high nitrogen treatment increased the soil pH by 3.44%, reduced the salt content by 5.35%, increased the organic matter by 16.89%, increased the available nitrogen by 83.83%, and decreased the available phosphorus by 33.84%. In short, the application of nitrogen to the soil of jujube orchard in alkaline land in-creased the content of organic matter, available nitrogen, and available potassium in the soil, and reduced the soil salt content. However, it increases soil pH and reduces available phospho-rus. The more Nitrogen is applied, the greater the soil pH, organic matter, and available nitrogen; high amounts of nitrogen will reduce soil available potassium. Among the various phenological stages, the organic matter and available phosphorus content are the highest in the germination stage, the pH and salt content are the highest in the flowering stage, and the available nitrogen and available potassium are the highest in the fruit setting stage; the available Nitrogen is the lowest in the flowering stage, and the salt, pH and organic matter in the young fruit stage are the lowest. The quick-acting phosphorus is the lowest in the mature stage, and the quick-acting Po-tassium is the lowest after the fruit picking.