Optimal irrigation strategies: land as limiting factor of production

Abstract

A study for the definition of optimum irrigation strategies was done based on total cost functions and answer functions of bean crop (Phaseolus vulgaris L.) to water and nitrogen factors obtained in Ilha Solteira, SP, Brazil (20°22'of latitude South, 51°22' of longitude West, and altitude of 335 m). The land, as a limiting factor, as well as different relations between the water cost and product price were also taken in consideration. In this study, the water depth ranging from 200 to 800 mm was considered profitable. The major net profit, US$ 510.40/ha and the major profitability (75%) were obtained with 90 kg/ha of N. Under this condition, the rational management of water ranged from 400 to 600 mm. P_w/P_i<1, may be considered as an indication of economical viability of the irrigation.