The effect of an intelligent surface drip irrigation method on sorghum biomass, energy and water savings

Over the last few decades, precipitation has decreased as a result of climate change. This change increases crop water requirements, while irrigation water is wasted because of improper irrigation scheduling. Soil moisture sensors could be used to improve irrigation scheduling and save both water and energy. The objective was to study the energy and water savings, and the gross margin achieved, when using an intelligent surface drip irrigation method on sorghum bicolor (L.) Moench. In the years 2008 and 2009, a study was conducted at the farm of the University of Thessaly, Central Greece. A Class A evaporation pan and an automated frequency domain reflectometry soil moisture sensor were used for irrigation scheduling. Two treatments in four replications were organized in a randomized complete block design: (1) pan surface drip irrigation (PSDI100) and amount of water equal to 100 % of the daily evapotranspiration (ETd), as determined by a Class A evaporation pan, and (2) automated surface drip irrigation (ASDI100) and amount of water equal to 100 % of the ETd, as determined by an automated soil moisture sensor. The mean dry biomass production and the gross margin were greater in the PSDI100 treatment. The fully automated treatment remained profitable despite the high first costs. The mean water saving was 12.5 %, while the mean energy saving was 12.4 %, and the irrigation water-use efficiency was higher in the ASDI100 treatment.