Abstract

Technology transition is an essential activity of engineering that bridges the gap between theory and reality. Computer engineering, for instance, takes the infinite accuracy of pure mathematics and applies it to practical situations. For precision irrigation and the calculation of ETc (estimated crop water use), we have the physics and mathematics expressed in the UN’s excellent documentation. A previous paper by the author expressed those mathematics in open-source software. The results were tested against the UN’s documentation and applied to Teff, a crop grown in Ethiopia. Since weather data had to be constructed from what was available, this present paper focuses on sweet corn grown in the USA, while using unmodified weather data downloaded from a regional weather station. It also goes into detail on determining various parameters required for calculation. An additional stop was to use next-day rain prediction in an effort to further minimize water use. Next-day rain prediction resulted in a 20% decline in water use while the crop would never go more than 24 h without an appropriate amount of water being applied. The result also demonstrates the integration of software components with a small cigarette-pack sized computer suitable for embedding within irrigation systems. Finally, ETc is translated into a volume of irrigation to be applied on a daily basis, taking into account moisture already available, ETc, and rain falling during the previous 24 h. Growing-season volume appears large at first glance but correlates with other consumption studies.

Key words: Precision irrigation, precision agriculture, distributed systems, water conservation, soil moisture, evapotranspiration, adaptive automation, embedded systems