小麦-玉米轮作制中氮肥效应模型的选择──经济和环境效益分析

从经济和环境效益两个方面对描述冬小麦、夏玉米轮作制中作物产量对氮肥反应的四个施肥模型（二次型，平方根，二次型＋平台，线性＋平台）进行了比较研究，结果表明，不同模型的拟合程度都较高，且拟合程度和计算的最佳产量均无显著差异，但线性＋平台和二次型＋平台模型推荐的最佳施肥量大大低于二次型模型，因而经济效益较高，研究还表明，与二次型模型相比，采用线性＋平台和二次型＋平台模型推荐和最佳施肥量，有利于维持土壤无机氮的基本平衡（而不是显著上升！）平台和二次型＋平台模型推荐的最佳施肥量，有利于维持土壤无机氮的基本平衡（而不显著上升！），提高氮肥利用率，并使小麦、玉米茎秆含氮量降低，表现出较佳的环境效应。

ECONOMIC AND ENVIRONMENTAL EVALUATION ON MODELS FOR DESCRIBING CROP YIELD RESPONSE TO NITROGEN FERTILIZERS AT WINTER-WHEAT AND SUMMER-CORN ROTATION SYSTEM

Several models (quadratic,square root, linear+plateau, quadratic+plateau) used for describing crop yield response to N fertilizer at winter-wheat and summer-corn rotation are compared. Data from four experiments which were conducted at Beijing and Henan province are used. All models fit the data equally well evaluated by using the R² statistic, but using linear+plateau model can reduce optimum N rate, increase economic profit of N fertilizer at the premise that crop yield don't reduce. Analyzing from environmental factor, linear+plateau model can maintain the balance of soil inorganic N, improve N fertilizer recovery, reduce crop straw N content and the emission of NOx by straw burning. So, linear+plateau model is the most suitable model in winterwheat and summer-corn rotation system in north of China.