Generally, this can be done through tracking and quantifying water fluxes at different spatial and temporal levels. Monitoring the plant rooting zone - where water sources from rainfall, irrigation, plant transpiration, and drainage losses from crop-growing areas intersect – remained a challenge until innovative technologies using the Internet of Things (IoT) recently entered the playing field. Smart sensors using isotopic and nuclear techniques can tell farmers which part of their fields actually need water at any given time. The sensors transmit data to a cloud platform, allowing farmers to better manage their type of crops, the growth stages, and the overall agro-ecosystem to minimize not only resource use but also nutrient losses.
Illustration Photo: Soybeans plants affected by drought near Navasota, Texas, USA on Aug. 21, 2013. (credits: USDA photo by Bob Nichols / Flickr Creative Commons Attribution 2.0 Generic (CC BY 2.0))