A Passive Drip Irrigation Controller for Efficient Water Use

在全球范围内，农业灌溉控制通常是通过对作物需水量的粗略估计、农民的直觉或使用基于定时器的控制器的时间表来完成的。这往往导致浇水过多或不足，导致植物生长减少和个人收入损失，特别是对缺水地区的小农而言。土壤湿度传感器是存在的，但它们没有被广泛采用，它们仍然需要农民亲自访问每种作物以控制灌溉。此外，农村地区普遍缺乏电力基础设施，难以使用电动灌溉设备（定时器、驱动阀、抽水设备）。 这里开发的无源灌溉控制器（PIC）可以自动调节灌溉网络的水流量，而无需电力或外部控制信号。它通过机械测量土壤水势来感知作物对水的需求，这是一种衡量土壤干燥程度的方法，并直接使用这种机械测量来打开或关闭水控制阀。PIC的开发处于后期原型阶段。此前，我们在实验室环境中验证了PIC可以在预定的土壤水势设定点可靠且一致地打开。我们已经对设计进行了多次迭代，目前正在比较PIC与基于定时器的控制器在温室中种植西红柿的灌溉性能。 旱地农研中心和圭尔夫大学的技术开发人员对实施工作有着浓厚的兴趣。 这个Lab2Market计划将使我们能够定位该技术，以实现最大的影响。

Globally, irrigation control for agriculture is typically done using rough estimations of a crop's water needs, a farmer's intuition, or on a schedule using a timer-based controller. This often leads to over- or underwatering, resulting in decreased plant growth and a loss of personal income, particularly for small farmers in regions experiencing water scarcity. Soil moisture sensors exist, but they are not widely adopted, and they still require the farmer to physically visit each crop to control the irrigation. Also, the general lack of electrical infrastructure in rural areas makes the use of electrically powered irrigation equipment (timers, actuation valves, pumping equipment) difficult to implement. The passive irrigation controller (PIC) being developed here automatically regulates the flow of water to an irrigation network without the need of electricity or an external control signal. It senses the crop's need for water by mechanically measuring the soil water potential, a measure of how dry a soil is, and directly uses this mechanical measurement to open or close the water control valve. The development of the PIC is in late-stage prototyping. Previously, we have validated in a laboratory setting that the PIC can open reliably, and consistently, at pre-determined soil water potential setpoints. We have made several iterations on the design and are currently comparing the irrigation performance of the PIC against a timer-based controller for growing tomatoes in a greenhouse. There is strong interest in implementation from technology developers at both ICARDA and the University of Guelph. This Lab2Market program will enable us to position the technology for maximum impact.