Modern rice varieties adapted to aerobic (dryland) conditions have expanded to new rice growing systems thanks to their plasticity in adapting to rainfed and irrigated conditions. This is important because, as water becomes scarce in paddy rice regions (as it is already in Australia), there will be a move towards tropical to subtropical dryland rainfed rice with attendant problems of drought and low temperature. To assess rice adaptability in the wet season of the semi-arid subtropical conditions of coastal central Queensland, field experiments were established for a late season (in January) planting in 2014 and early season planting in November 2015 with 13 varieties developed by Australian Agriculture Technologies (AAT) Ltd were seeded in a vertisol soil. This was to assess their adaptation to rainfed conditions and their response to strategic irrigation. Water scarcity and low temperature prior to and at flowering were important factors constraining yield. Early flowering varieties in the late season planting escaped the otherwise cold and drought stress during the reproductive stage and had higher yields. In the second year, earlier planting made possible with strategic irrigation avoided the low temperature constraint on yield, but without follow-up strategic irrigation, yields were still low. The average yield of varieties increased from 1.5 times (AAT 4) to 16.3 times (AAT 15) with strategic irrigation compared with rainfed yields averaged across years. The increase in yield with strategic irrigation was associated with a greater leaf area index, spikelet fertility, and instantaneous water use efficiency during flowering. Strategic irrigation concentrated roots in the top 15 cm, but differences in yield between varieties under rainfed conditions were not related to root properties. It is important to consider variations in flowering time, yield potential, and drought patterns when developing rice varieties for rainfed semi-arid tropical conditions, as well as when quantifying the benefits of strategic irrigation.

中文翻译：

---

亚热带地区是否进行战略灌溉的有氧水稻

适应有氧（干旱地区）条件的现代水稻品种因其可适应雨育和灌溉条件的可塑性而扩展到新的水稻种植系统。这很重要，因为随着稻米地区（澳大利亚已经很缺水）的缺水，将有热带向亚热带旱地雨养水稻的转移，随之而来的是干旱和低温问题。为了评估昆士兰州中部沿海半干旱亚热带条件下湿季的水稻适应性，对澳大利亚农业技术公司开发的13个品种进行了2014年后期（1月）播种和2015年11月早期播种的田间试验。 （AAT）Ltd播种在粉质土壤中。这是为了评估它们对降雨条件的适应性以及对战略灌溉的响应。开花前和开花时的缺水和低温是限制产量的重要因素。在播种后期，早花品种在繁殖期摆脱了寒冷和干旱的压力，单产更高。在第二年，采用战略灌溉可以更早播种，从而避免了低温对产量的限制，但是如果不进行后续战略灌溉，单产仍然很低。与多年平均雨养产量相比，战略灌溉使该品种的平均产量从1.5倍（AAT 4）增加到16.3倍（AAT 15）。战略灌溉的产量增加与更大的叶面积指数，小穗肥力，开花期间的瞬时水分利用效率。战略灌溉将根系集中在最上面的15 cm处，但是在雨育条件下，不同品种之间的产量差异与根系特性无关。在开发用于雨养半干旱热带条件的水稻品种以及量化战略灌溉的效益时，必须考虑开花时间，单产潜力和干旱模式的变化。