Soil water energetic status and cowpea beans irrigated with saline water

Abstract

The study of the water energetic status under saline condition and its impact on the development of cowpea is of extreme importance, since this crop is the food base in many parts of the world. An experiment was carried out in a greenhouse from March to May 2014 using the cultivar IPA 206 in Fluvisol collected in the municipality of Pesqueira, PE, Brazil. Waters with six levels of electrical conductivity (0; 2.5; 5; 7.5; 10; 12.5 dS m-1) formulated with NaCl and a salt mixture were used. The experiment was conducted in randomized blocks in a 6 × 2 factorial arrangement with four replicates, forming 48 experimental plots. The matric, osmotic and total potential of water in the soil, the osmotic, and water potential in the plant and atmospheric potential were determined. Plant and soil osmotic potentials decreased with the increase in irrigation water electrical conductivity, which contributed to the decrease in plant water potential. There was no significant difference between the salts used in the composition of the irrigation water for the potentials evaluated in the soil and in the plant; there was no equilibrium between soil and plant water potentials at predawn.