增施氮肥和地面管理对酸樱桃园土壤营养状况的影响

Effects of Nitrogen Application and Soil Management on Soil Nutrient Status in Sour Cherry Orchard

在一个连续进行了 ８年Ｎ肥定位试验的酸樱桃园，调查了每年施用 Ｎ６０ ｋｇ· ｈｍ^(－２)和行间生草制对土壤营养状况的影响。结果表明：在肥沃土壤里ＮＨ_４~＋是速效Ｎ的主要存在形式，而ＮＯ_３~－的含量很低。生草地土壤中含有较多的 ＮＨ_４~－，而清耕带土壤中含有较多的 ＮＯ_３~－。施肥增加土壤速效 Ｎ的含量。土壤 ＮＯ_３~－的季节性变化表明 ５至 ６月份土壤中 ＮＯ_３~－的含量高，而花前和 ７月份土壤中 ＮＯ_３~－含量低。 Ｐ、Ｋ在清耕带 １０ ｃｍ以下土壤的含量低于生草地土壤，但在 ０～ １０ｃｍ土层中Ｋ的含量高于生草地。Ｐ的含量不受影响。施Ｎ减少了土壤Ｐ、Ｋ的含量。土壤中Ｍｇ的含量分布均匀，不受施Ｎ和地面管理制度的影响。

Investigation on soil nutrient status and pH were carried out in an 8-year old sour chery orchard testing for nitrogen fertilization. The results showed that application of 60kg N·hm^(-2) annually increased soil content of NH_4^+ and NO_3^-, but decreased the levels of P and K. The soil under grassed elleyways had higher NH_4^+, and K, but lower NO_3^- than the soil under herbicide strip, with exception that the soil in the layer of 0 10 cm under herbicide strip had higher content of K. The distribution of Mg in soil was rather uniform throughout the soil profile and unfacted by N fertilization and floor management system.