英文文献：Effect of Nitrogen Fertilization and Liming on Rye-Ryegrass Yield and Soil pH Dynamics-施氮和浸灰对黑麦草产量和土壤pH动态的影响
英文文献作者：Tumusiime, Emmanuel,Brorsen, B. Wade,Biermacher, Jon T.,Mosali, Jagadeesh
英文文献摘要：
Using ammonium based nitrogen fertilizers in crop production has been shown to acidify soils. Lime used to correct soil pH is an important cost to producers. Recommendations of the optimal level of nitrogen to apply typically ignore the cost of lime created by nitrogen fertilization. This study was aimed to estimate soil pH change in response to nitrogen and lime application, and determine the effect of considering the cost of lime on recommendations about the optimal level of nitrogen. Yield response and pH functions were estimated and used to determine optimal levels of inputs. The effect of the cost of lime on recommendations about the optimal level of nitrogen was found to be marginal. Nitrogen acidification was found to be more severe with nitrogen application amounts above recommended rates than with nitrogen that is used by the plant.

在作物生产中使用铵基氮肥已被证明会使土壤酸化。石灰用于校正土壤pH值对生产者来说是一项重要的成本。建议的最佳施氮水平通常忽略氮肥产生的石灰成本。本研究旨在评估土壤pH值对施氮和石灰的响应，并确定考虑石灰成本对最佳施氮水平建议的影响。产量响应和pH函数被估计和用来确定最佳水平的投入。石灰的成本对建议的最佳氮水平的影响被发现是边际的。研究发现，施氮量超过推荐量时，氮肥酸化比植物使用氮肥时更为严重。