Abstract Automated irrigation scheduling of grain crops using a combination of plant and soil water sensing feedback has not been widely investigated. A three-year study was conducted at Bushland, Texas to investigate irrigation management of grain sorghum (Sorghum bicolor, L.), in 2012 using plant feedback with a single thermal stress threshold, and in 2018 and 2019 using multiple thermal stress thresholds and a combination of plant and soil water sensing (Hybrid) feedback. The goals of the studies were to optimize grain yield, crop water productivity (CWP) and irrigation water productivity (IWP) using sensor feedback at irrigation levels similar to 80 %, 50 % and 30 % (designated I80, I50 and I30) replenishment of soil water depletion to field capacity as determined with weekly neutron probe readings (the “manual” method). Results in 2012 indicated that irrigation scheduling using plant feedback alone with a single thermal stress threshold produced grain yields that were significantly less (0.49 and 0.38 kg m−2) compared with the manual method (0.63 and 0.51 kg m−2) at the I80 and I50 treatment levels, respectively. However, in 2018, the Hybrid feedback method produced mean grain yields (0.87 kg m−2) that were significantly greater compared with the plant feedback (0.76 kg m−2) and manual (0.74 kg m−2) irrigation scheduling methods at the I80 treatment level. In 2019, mean grain yields (0.86, 0.83 and 0.88 kg m−2), CWP (1.25, 1.29 and 1.20 kg m-3) and IWP (2.11, 2.19 and 1.88 kg m-3) for the Hybrid, plant feedback and manual methods, respectively, were similar at the I80 level. These results suggest that plant and soil water sensing feedback using multiple thermal stress thresholds and watering levels have the potential to produce optimal crop response for grain sorghum. More research is required to test the efficacy of soil water sensing in combination with plant sensing for other crops.

中文翻译：

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使用植物和土壤水分感应反馈的高粱特定地点灌溉 - 德克萨斯高原

摘要 结合植物和土壤水分传感反馈的粮食作物自动灌溉调度尚未得到广泛研究。一项为期三年的研究在德克萨斯州布什兰进行，旨在调查高粱（Sorghum bicolor, L.）的灌溉管理，2012 年使用具有单一热应力阈值的植物反馈，并在 2018 和 2019 年使用多个热应力阈值和一个植物和土壤水传感（混合）反馈的组合。研究的目标是在灌溉水平类似于 80%、50% 和 30%（指定为 I80、I50 和 I30）的灌溉水平下使用传感器反馈来优化谷物产量、作物用水生产率 (CWP) 和灌溉用水生产率 (IWP)根据每周中子探针读数（“手动”方法）确定的土壤水分消耗到田间容量。2012 年的结果表明，与 I80 的手动方法（0.63 和 0.51 kg m-2）相比，仅使用植物反馈和单一热应激阈值的灌溉计划产生的谷物产量显着降低（0.49 和 0.38 kg m-2）和 I50 治疗水平，分别。然而，在 2018 年，与植物反馈（0.76 kg m-2）和手动（0.74 kg m-2）灌溉调度方法相比，混合反馈方法产生的平均粮食产量（0.87 kg m-2）明显更高。 I80 治疗水平。2019 年，杂交种、植物反馈和 2019 年平均粮食产量（0.86、0.83 和 0.88 kg m-2）、CWP（1.25、1.29 和 1.20 kg m-3）和 IWP（2.11、2.19 和 1.88 kg m-3）手动方法分别在 I80 水平上相似。这些结果表明，使用多个热应激阈值和浇水水平的植物和土壤水感反馈有可能为高粱产生最佳作物响应。需要更多的研究来测试土壤水分传感与植物传感对其他作物的功效。