Towards water sustainability in agriculture through closed-loop irrigation

水是我们日常生活的必需品。在过去的十年里，确保水和粮食安全的挑战一直被世界经济论坛视为最重大的全球风险之一。人口增长是导致全球供水危机的主要因素。用水最多的是农业，约占淡水总消耗量的70%。在加拿大，艾伯塔省、不列颠哥伦比亚省和萨斯喀彻温省是灌溉用水量最大的三个地区。根据艾伯塔省政府的一份报告，艾伯塔省分配给灌溉的水量已经达到上限。任何灌溉面积的进一步增加都需要主要来自于水效率的提高。在25年萨斯喀彻温省水安全计划中，高效利用水被确定为缓解日益增加的供水压力的首要行动领域。虽然农业消耗的淡水最多，但由于当前灌溉策略的开环性质，农业灌溉的平均用水效率很低(估计在50%到60%左右)。在目前的农业灌溉实践中，灌溉水量和灌溉时间基本上是由灌溉者(农民)根据灌溉者的知识和收集的各种辅助田间数据(如天气信息、蒸散量(ET)、随机采样的土壤水分)以开环的方式预先确定的。然而，在过程控制中，开环控制是非常不精确的，这是众所周知的。也就是说，开环灌溉通常会导致过量灌溉或灌溉不足，这意味着水分利用效率较低。该项目的目标是关闭灌溉决策过程，开发出一种闭环系统的精确灌溉解决方案，以显著提高农业用水效率。该项目具有巨大的社会影响，将为水的可持续性、国家和全球粮食安全以及温室气体减排做出贡献。

Water is essential for our daily life. The challenge of ensuring water and food security has been consistentlyrecognized as one of the most significant global risks by the World Economic Forum over the past decade.Population growth is the primary factor causing the global water supply crisis. The most substantial use offreshwater is in agriculture, which accounts for about 70% of the total freshwater consumption. In Canada,Alberta, BC and Saskatchewan are the top three irrigation water consumers. According to a report of theGovernment of Alberta, the water allocated to irrigation in Alberta is already capped. Any further increase inirrigated acres needs to come primarily from improvements in water efficiency. In the 25 Year SaskatchewanWater Security Plan, efficient use of water is identified as the No. 1 action area to relieve the increasedpressures on water supplies. While agriculture consumes the largest amount of freshwater, the averageagriculture irrigation water efficiency is low (estimated to be around 50% to 60%) due to the open-loop natureof the current irrigation strategy.In the current agricultural irrigation practice, the amount of water to be irrigated and the time to apply theirrigation are essentially determined in advance by the irrigator (the farmer) based on the irrigator's knowledgeand various collected auxiliary field data (e.g., weather information, evapotranspiration (ET) rate, randomlysampled soil moisture) in an open-loop fashion. However, it is well recognized in process control thatopen-loop control is quite imprecise. Namely, open-loop irrigation generally leads to either over-irrigation orunder-irrigation, which implies low water-use efficiency. The goal of this project is to close the irrigationdecision-making process to develop a closed-loop precision irrigation solution to significantly improve thewater-use efficiency in agriculture. This project has a great societal impact and will contribute to watersustainability, national and global food security, and greenhouse gases emission reduction.