Impact of supplementary irrigation with saline water in a Neossol of the semi-arid

Abstract

The present study was conducted in an alluvial valley with potential risk of salinization associated to quality of the available groundwater. The study was carrided out in a plot planted with carrots (Daucus carota L.) using trickle irrigation in the beginning of the rainy season. The performance of the irrigation management using saline water (EC = 1.38 dS m^-1) was evaluated based on partial leaching of salts and maintenance of adequate moisture and salt contents in the soil profile. A decrease in the electrical conductivity of soil water was observed in the 0-100 cm depth after irrigation application, especially in the root zone. Numerical simulations of water flow and salt transport in the unsaturated zone were performed. The simulation results reproduced well field measured pressure heads and salt concentrations. It was verified, through modeling, that the alternative of incomplete leaching is adequate when compared with complete leaching, considering both salinity of the irrigation water and crop tolerance to salinity.

Key words:
incomplete leaching; numerical modeling; salinity