Basic economics on deficit irrigation and water quality dynamics for horticulture production in a greenhouse environment

The objective of this paper is to examine the impact of varying deficit irrigation level and water quality scenarios on economic responses of tomatoes (Solanum lycopersicum cv. Izmir) produced in a greenhouse environment. Groundwater, recycled wastewater and a blend of both were selected as water qualities. Four irrigation scenarios were maintained including soil moisture at 60%, 70%, 80% and 100% of field capacity. The treatment maintaining soil moisture at 100% field capacity was control in this study for each water quality. The selected irrigation method and the soil texture were the drip and loamy sand respectively. The effects of deficit irrigation and water quality on the benefit-cost ratio, revenue generated per m3 of water usage, cost function and net financial return were examined. Benefit-cost ratio was a maximum of 1.37 for the control treatment of recycled wastewater. All the selected deficit irrigation treatments produced the benefit-cost ratio more than one except 60% field capacity level. Revenue generation per m3 of water usage was found the highest in treatments maintaining soil moisture content at 80% field capacity despite of water quality. Based on the benefit-cost ratio, cost function and revenue generated per cubic meter of water use, this study recommended the deficit irrigation level at 80% field capacity as the most cost-effective and water efficient strategy for greenhouse grown tomatoes.