• ISSN 1008-505X
  • CN 11-3996/S

基于“最优氮肥偏生产力”推荐氮肥用量

Using “the optimal partial factor productivity of nitrogen” for nitrogen fertilization recommendation

  • 摘要: 合理确定氮肥用量对于提高氮肥利用效率至关重要。目前氮肥总施用量推荐方法包括氮肥效应函数法、斯坦福公式、测土配方施肥、养分综合管理和计算机决策系统(如养分专家系统)等。这些方法各有优点,但是普遍要求较强的专业知识和养分测试技术条件。本研究提出一种简便的、基于“最优氮肥偏生产力”的氮肥总量推荐方法。该方法基于区域多点氮肥梯度试验,构建氮肥效应曲线,并据此确定最高产量及相应的最佳氮肥用量,最后计算出最优氮肥偏生产力(即:最优氮肥偏生产力=作物最高产量/最佳氮肥施用量)。在实际应用时,用户根据田块的预期目标产量,利用“氮肥推荐量 = 目标产量/最优氮肥偏生产力”公式,即可获得相应的氮肥推荐用量。该方法操作简单,不需要评估土壤供氮能力、氮肥利用率等难以估计的参数,亦可避免土壤取样、测试及推荐指标建立等环节中产生的各种误差,方便农技推广人员和农户使用。以玉米为例,本研究论证了这一方法的可行性及其应用中应考虑的问题。

     

    Abstract: Reasonable application rate of nitrogen fertilizer is pivotal for improving nitrogen use efficiency. Various recommendation methods for nitrogen fertilization have been approached in recent several decades, such as the nitrogen response function method, the Stanford formula, formula fertilization based on soil testing, integrated nutrient management, computer decision systems (such as nutrient expert systems), etc. While each of these methods boasts its own merits, they necessitate a certain level of professional expertise and nutrient testing facilities. In response, this study proposed a straightforward method for determining the total nitrogen fertilizer requirement, grounded in the “optimal partial factor productivity of nitrogen (PFPNopt)”. This method leverages the nitrogen response curve derived from nitrogen gradient experiments conducted across multiple sites within a specific region. By identifying the maximum yield and the corresponding optimal nitrogen fertilizer application rate, PFPNopt is calculated as the ratio of the highest crop yield to the best nitrogen fertilizer application rate. In practical terms, once the target yield for a particular field plot is estimated, the recommended nitrogen fertilizer quantity can be readily derived using the formula: recommended N fertilizer = target yield/PFPNopt. This approach is user-friendly, as it obviates the need to account for challenging-to-estimate parameters such as soil nitrogen supply capacity and nitrogen fertilizer utilization efficiency. Consequently, it mitigates potential errors associated with soil sampling, testing, and recommendation index formulation, thereby facilitating its adoption by agricultural technicians and farmers alike. To illustrate the method’s viability, this study employs corn as a case study and delves into the considerations that should be taken into account during its implementation.

     

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