Consumo hídrico e viabilidade econômica da cultura do feijão caupi cultivado em clima semiárido

Abstract

This study was carried out under field conditions at the Experimental Farm of the Agricultural Research Company of Rio Grande do Norte, in Apodi, RN. To determine irrigated cowpea bean crop water consumption Penman-Monteith methods were used, to estimate reference evapotranspiration and energy balance based on Bowen ratio to estimate crop evapotranspiration and crop coefficient. The experiment was conducted using an experimental plot of 4.0 ha cultivated with cowpea cultivar Potiguar, with 70 cm between rows and plant density of 4 plants m-2. The irrigation system with sprinkler used produced a water depth of 463.7 mm at the end of the experiment. The results showed that the water requirement of cowpea was higher in the period of vegetative growth (159 mm), while for the entire cycle it was 400.1 mm. The cowpea crop under irrigation is economically viable in the study region, with net income 37% higher than that of rain fed system.