Best management practices of a solar powered mini-pivot for irrigation of high value crops

During the 2005 growing season two irrigation management practices were developed for cabbage production utilizing a Greenfield solar powered miniature pivot, located at the Canada-Saskatchewan Irrigation Diversification Centre (CSIDC) near Outlook, Saskatchewan. Solar and battery power was used to operate the drive and control system of the miniature centre pivot located on CSIDC’s pressurized pipeline. The management practices included a low-flow, 94 litres per minute (lpm) schedule with irrigation events occurring in the evening and night periods, and a high-flow, 370 lpm schedule with irrigation events occurring during the daytime hours. In each management practice, the soil moisture content was maintained above 65% of field capacity to optimize yield and head development (Waterer 2005).Over the 2006 growing season, testing was conducted to evaluate the performance of each management practice. Performance was based upon application uniformity, water use efficiency and energy use efficiency. In addition to performance evaluation, tests were conducted to determine operational characteristics of this relatively new irrigation system to identify potential use in agricultural production. The uniformity coefficient of the high-flow management practice was greater than that of the low-flow management practice. This was a result of nozzle selection and layout of each application system, as determined by the manufacturer. Water use efficiency increased significantly when converting from a high-flow operating system to the low-flow system. This increase in water use efficiency was a result of reduced water loss, in the high flow system, through evaporation and potential run-off due to decreased application rates and environmental factors between watering times. Water loss through this manner is not beneficial to plant growth and results in elevated operating costs with little to no improvement in yield. Energy use efficiency, due to differences in water use efficiency and friction loss in the piping system, also increased upon switching from a high-flow system to the low-flow system. In general, converting this type of system from a high-flow management practice to a low-flow management practice will help conserve water and energy resulting in savings in operating and capital costs.Testing to determine the operating characteristics of the power system was completed during the 2006 growing season. It was concluded that these systems have potential use in operating small-scale pivot and pumping systems on high-value crops