Affordable Soil Moisture Sensors
More Crop per Drop: An automatic irrigation system based on reliable and real-time indicators of plant water needs
Agriculture accounts for 70 percent of freshwater use worldwide. Current irrigation practices—from greenhouses to farms—rely on imprecise indicators of when (and for how long) plants should be watered. For example, ornamental growers typically determine plants’ watering needs by picking up a pot to see if it’s light or heavy, or sticking a finger in the soil to detect moisture. Others merely put irrigation on a timer, which waters plants whether they need it or not. Most large-scale agricultural operations utilize similarly inefficient irrigation techniques.
According to some estimates, irrigated plants tend to receive 5–20 times more water than they can actually use. Over-irrigation results in both increased strain on already scarce water supplies, and increased water pollution due to nutrient-rich run-off, which leads to surface-water algal blooms and groundwater contamination. Despite these environmental and health concerns, growers would rather err on the side of over-watering rather than risk the possibility that crops will die or underperform due to water stress.
Professor van Isle is collaborating with other faculty from the University of Georgia to develop affordable soil moisture sensors as part of a multi-institute research initiative (called Smart Farms) to save water, increase efficiency, and reduce the environmental impacts of plant production, while simultaneously maximizing potential growth. A network of sensors directly measures variables both in the rooting environment and from the aerial environment. Irrigation is then automatically activated according to changes in soil moisture as plants take up water.
“This is the next generation of tools to precisely monitor and control water applications based on actual plant needs in order to optimize growth and minimize environmental damage due to leaching and runoff” —Marc van Isle, PhD, Professor of Plant Nutrition and Physiology
The goal of this innovation is to provide growers with cost-effective tools that can be used to reduce inputs, increase profitability, and encourage sustainable practices in order to conserve water and protect the environment. At this stage the focus is greenhouses and nurseries, but the system will eventually be applicable to agriculture and landscaping.
“We hope in the long run that we can come up with a simplified version that can be used in developing countries where water is very limited” —Marc van Isle, PhD, Professor of Plant Nutrition and Physiology