US: Wireless sensor-based irrigation systems can offer significant benefits to greenhouse operators. The authors of a report published in HortTechnology have revealed that the use of sensor-based irrigation technology can also accelerate container and greenhouse plant production time. Advances in sensor technology and increased understanding of plant physiology have made it possible for greenhouse growers to use water content sensors to accurately determine irrigation timing and application rates in soilless substrates. The wireless sensor systems provide more accurate measurements of substrate moisture than qualitative methods, and can save irrigation water, labor, energy, and fertiliser.
Erik Lichtenberg, John Majsztrik and Monica Saavoss of University of Maryland, reported on a study they designed to determine an optimal formula for ascertaining the true profitability of precision irrigation systems. The researchers designed a methodology for calculating profitability taking differences in timing into account, and then applied the methodology to data from gardenia production in a Georgia nursery. According to the researchers, the most convenient method of calculating profitability is converting all revenues and costs to constant periodic payments; eg, annualising them. The scientists found that controlling irrigation using data from moisture sensors led to substantial reductions in both production time and crop losses. The weighted average time from planting to sale was over one-third lower, while crop losses were reduced by 50%. Calculations showed that annualised profit under the wireless sensor system was over 1.5 times more than under the nursery's standard practice, and that most of the increase in profit was attributed to a reduction in production time. Lichtenberg, Majsztrik and Saavoss concluded that, even if efficiency gains are not as high as those in the study, controlling irrigation using wireless sensor systems is likely to increase profitability substantially. They added that wireless sensor systems can have environmental benefits as well as the economic benefits shown in the study.
Source: See daily