The northeast United States has experienced higher temperatures, more annual precipitation, and more frequent heavy rain events in recent decades. These trends appear likely to continue, and they may depress crop yields and exacerbate environmental problems associated with the region’s dairy farms. To investigate these possibilities, we used the Agricultural Policy/Environmental eXtender (APEX) model to simulate runoff, erosion, nutrient losses, and crop yields on two Vermont farms in a small set of possible future climates. Raising temperatures by 2°C, combined with increasing total precipitation or changing the seasonality of precipitation, had relatively modest effects on any outcome (less than 10% change in median values). However, a combination of higher temperatures and more intense precipitation led to increased runoff volumes and larger soil and nutrient losses. Median values of runoff, sediment, and nutrient losses increased by 2% to 15% at one site and by 36% to 58% at the other (although the changes at the latter site were relative to very low baseline values), while the 95th percentile rose by 6% to 19% and 53% to 65%. This suggests that management practices adapted to reducing runoff etc. in extreme precipitation events will be increasingly valuable in the coming years. Corn (Zea mays L.) silage yields changed by less than 10% in all simulations, and in some cases increased slightly. However, modeling that includes many additional factors that can reduce yields (such as new pests, or delays to farm operations in wet conditions) is needed for a more complete understanding of how climate change may affect the viability of forage production on dairy farms in this region.

中文翻译：

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奶牛场在温暖湿润气候下的农艺和环境绩效

近几十年来，美国东北部经历了更高的温度、更多的年降水量和更频繁的大雨事件。这些趋势似乎可能会持续下去，它们可能会降低作物产量并加剧与该地区奶牛场相关的环境问题。为了研究这些可能性，我们使用农业政策/环境扩展 (APEX) 模型来模拟未来可能出现的一小组气候中两个佛蒙特州农场的径流、侵蚀、养分损失和作物产量。气温升高 2°C，加上总降水量增加或降水的季节性变化，对任何结果的影响都相对较小（中值变化不到 10%）。然而，更高的温度和更强烈的降水相结合导致径流量增加和更大的土壤和养分损失。径流、沉积物和养分损失的中值在一个站点增加了 2% 到 15%，在另一个站点增加了 36% 到 58%（尽管后一个站点的变化相对于非常低的基线值），而第 95百分位上升了 6% 至 19% 和 53% 至 65%。这表明在极端降水事件中适应减少径流等的管理做法在未来几年将变得越来越有价值。在所有模拟中，玉米 (Zea mays L.) 青贮饲料产量变化不到 10%，在某些情况下略有增加。然而，包括许多会降低产量的其他因素（例如新的害虫、