Jornada diária de trabalho como critério de dimensionamento econômico para sistemas de irrigação por pivô central

Abstract

Considering the relevance of central pivot irrigation in Brazil and its recent expansion, especially in the Center-West Region, the aim of this was to evaluate central pivot dimensioning criteria that minimize the total cost of irrigation, through the optimization of the system capacity. Energy is one of the main costs of irrigation, so its rate adequacy allows the reduction of the consumption costs due to different categories of energy rates. Thereby, a methodology was proposed in which different daily operation times were evaluated in order to find the one that manages the lowest total cost in order to balance the energy costs with the costs of assembling a central pivot. The results showed that the minimum total cost was obtained for the smallest lateral line diameter, 6 5/8”, and the biggest daily operation time, 24 h d-1. It leads to a smaller system capacity of 0.822 L s-1 ha-1, since it is possible to fit the equipment into the B2 Rural subgroup. Under a seasonal and hourly energy rate, the lowest total cost was obtained for the largest lateral line diameter, 8”, a daily operation time of 21 h d-1 and a system capacity of 0.939 L s-1 ha-1, in which the Blue and Green energy rates are more favourable than the conventional one.