COST BENEFIT ANALYSIS IS TAKING INTO ACCOUNT THE COST OF IRRIGATION WATER FOR RICE

Abstract

The water’s relevance has been increasing in the context of irrigated agriculture, both in a quantitative and qualitative aspect. The cost analyses usually don’t take into consideration the aspects related to the water’s quality and treatments that are employed to make it proper to use. As the control over the use of hydric resources increases, it forces the agriculture to make use of low quality waters, what may come to turn its costs even more expensive. The present study aimed at realizing a cost benefit analysis taking into consideration the expenses with water employed to irrigate rice crops. It took place at the campus of the Federal University of Santa Maria – RS, from the analysis of two water reservoirs. After calculating the water’s quality rate as well as the expenses with its treatment and the water itself, the current rice production costs were then added to the final outcome, making possible to obtain a cost benefit ratio. This cost benefit ratio was less than one unit in all situations, showing that the irrigated rice production is currently impracticable. The water costs weren’t decisive for this outcome, but regarding to the price of a rice sack, it was higher than the inflation values in 2010. Finally, it was possible to conclude that the water cost is responsible for 7% of the production cost, what makes this research an efficient tool to help decision making processes when managing irrigation systems.