Increases in temperature, along with possible decreases in rainfall, will influence the production of forage on Australian dairy farms. A biophysical simulation study was undertaken to compare the performance of perennial pastures and annual forage cropping systems under a historical scenario and two possible future climate scenarios for three key dairy locations of south-eastern Australia. Pastures and forage-cropping systems were simulated with the biophysical models DairyMod and APSIM, respectively, for a location with a heavy reliance on irrigation (Dookie, Victoria), a location with a partial reliance on irrigation (Elliott, Tasmania), and a dryland location (Terang, Victoria). The historical climate scenario (baseline scenario) had no augmentation to climate data and an atmospheric CO₂ concentration of 380 ppm, whereas the two future climate scenarios had either a 1°C increase in temperatures (with an atmospheric CO₂ concentration of 435 ppm) and a concurrent 10% decrease in rainfall, or a 2°C increase in temperatures (with an atmospheric CO₂ concentration of 535 ppm) and a concurrent 20% decrease in rainfall. At Dookie, mean annual dry matter yields of the forage-cropping options and the pasture systems increased under both future climate scenarios but more irrigation was required. At Terang, the yield of forage-cropping systems increased whereas the yield of the pasture systems decreased under the future climate scenarios. At Elliott, yields of irrigated pastures and cropping systems increased but there was minimal or a negative impact on yields of dryland pastures and cropping systems under the future climate scenarios. At all three locations, forage production increased in the colder months of the year with a decrease in production during the warmer months. This study indicates that double-cropping and irrigated-pasture systems at all three locations appear resilient to projected changes in climate; however, for irrigated systems this assumes a reliable supply of irrigation water. The systems implications of how a shift in the seasonality of forage supply within these options impacts on the farm system as a whole warrants further investigation.

温度升高以及降雨可能减少，将影响澳大利亚奶牛场的饲料生产。进行了一项生物物理模拟研究，以比较澳大利亚东南部三个重要乳品场的历史情景和两种可能的未来气候情景下多年生牧场和一年生牧草种植系统的性能。分别使用生物物理模型DairyMod和APSIM对牧场和牧草系统进行了模拟，分别针对严重依赖灌溉的地区（维多利亚州Dookie），部分依赖灌溉的地区（塔斯马尼亚州Elliott）和干旱地区位置（维多利亚州Terang）。历史气候情景（基准情景）没有增加气候数据和大气中的CO ₂浓度为380 ppm，而两个未来的气候情景要么温度升高1°C（大气中的CO ₂浓度为435 ppm），同时降雨减少10％，要么温度升高2°C（当大气中的CO ₂浓度为535 ppm），同时降雨减少了20％。在杜基（Dookie），两种未来气候情景下，饲草作物和牧场系统的年平均干物质产量均增加，但需要更多的灌溉。在特朗，在未来的气候情景下，牧草系统的产量增加，而牧草系统的产量下降。在埃利奥特（Elliott），灌溉牧场和农作物系统的单产增加了，但在未来的气候情景下，对旱地牧场和农作物系统的单产产生的影响微乎其微或具有负面影响。在这三个地点，一年中最冷的月份牧草产量都增加了，而在最暖的月份中牧草产量却下降了。这项研究表明，在所有三个地点的双作和灌溉草场系统似乎都对预计的气候变化具有弹性。但是，对于灌溉系统，这假设可靠地供应了灌溉用水。这些选择中的草料供应季节性变化如何影响整个农场系统的系统含义值得进一步研究。