Enhanced-efficiency nitrogen fertilizers provide an opportunity for sustainable intensification of agricultural industries. However, field experiments evaluating yield and nitrogen loss benefits from enhanced-efficiency fertilizers often fail to obtain statistically significant treatment differences. Agricultural systems modeling provides a means to perform thousands of virtual response trials, allowing us to unravel the complex interactions between crop, management, and seasonal climate that determine the efficacy of these fertilizers. Here, we present simulations of controlled-release fertilizer use in Australian sugarcane (Saccharum sp. L.) production in a wet tropical climate. To quantify the agronomic and environmental benefits, we analyze the yield and nitrogen loss responses to nitrogen rate (response curves), comparing those for urea and controlled-release fertilizers. We also evaluate the impacts of soil type, crop start times, and controlled-release patterns as they interact with seasonal climate and rainfall distribution. The simulation results showed that nitrogen loss and yield benefits were highly variable, and their likelihood determined by three prerequisite conditions: (1) sufficient longevity of protection of the fertilizer nitrogen, (2) occurrence of a nitrogen loss event during this period of protection and before the nitrogen is taken up by the crop, and (3) the crop being responsive to the fertilizer nitrogen. These prerequisite conditions extend to other cropping systems as well as to other enhanced-efficiency nitrogen fertilizers such as nitrification inhibitors. Here, for the first time, we provide a framework for understanding the inconsistent results in field experiments testing the efficacy of enhanced-efficiency nitrogen fertilizers. This understanding will help improve the setting, design, and interpretation of experiments for better demonstration of benefits as well as identify where enhanced-efficiency fertilizers can best increase sustainability of nitrogen management.

增效氮肥为农业产业的可持续集约化提供了机会。然而，评估增效肥料的产量和氮损失效益的田间试验通常无法获得统计学上显着的处理差异。农业系统建模提供了一种执行数千次虚拟响应试验的方法，使我们能够解开决定这些肥料功效的作物、管理和季节性气候之间的复杂相互作用。在这里，我们展示了澳大利亚甘蔗（ Saccharum）中控释肥料使用的模拟。sp。L.) 在潮湿的热带气候下生产。为了量化农艺和环境效益，我们分析了产量和氮损失对氮率的响应（响应曲线），比较了尿素和控释肥料的响应。我们还评估了土壤类型、作物开始时间和控制释放模式与季节性气候和降雨分布相互作用的影响。模拟结果表明，氮素流失和产量效益差异很大，其可能性由三个前提条件决定：（1）肥料氮的保护寿命足够长，（2）在此保护期内发生氮素流失事件和在氮被作物吸收之前，以及（3）作物对肥料氮有反应。这些先决条件延伸到其他种植系统以及其他高效氮肥，例如硝化抑制剂。在这里，我们第一次提供了一个框架来理解田间试验中测试增效氮肥功效的不一致结果。这种理解将有助于改进实验的设置、设计和解释，以更好地展示效益，并确定在哪些方面增效肥料可以最好地提高氮管理的可持续性。我们提供了一个框架来理解测试增效氮肥功效的田间试验中不一致的结果。这种理解将有助于改进实验的设置、设计和解释，以更好地展示效益，并确定在哪些方面增效肥料可以最好地提高氮管理的可持续性。我们提供了一个框架来理解测试增效氮肥功效的田间试验中不一致的结果。这种理解将有助于改进实验的设置、设计和解释，以更好地展示效益，并确定在哪些方面增效肥料可以最好地提高氮管理的可持续性。