Diagnóstico da necessidade de drenagem em solo cultivado com bananeira "pacovan" irrigada com águas poluídas.

Abstract

In the brazilian seraiarid region using lower quality water in irrigated production systems is in many cases the only way to ensure agricultural production. The planned reuse of lower quality water contributes to better management of water resources, ensuring agricultural production in places where it is scarce factor of production. The research aimed to identify the need for drainage in soil cultivated with banana irrigated with surface water polluted the Farm Ponta da Serra, in the municipality of Queimadas, PB. To determine the hydraulic conductivity (Ko) and groundwater monitoring were installed six points drilled between rows of crops, with the help of auger. To identify the degradation of soil salts were evaluated by 32 points distributed in a regular grid (11,0m x 20,0m) positioned in the lines of cultivation. Two soil samples were collected for physicochemical analysis and subsequent classification, held in february and november 2012 characterized by rainy and shortage of rainfall, respectively. At the root layer of a higher concentration of the culture was determined by the content of added salts irrigation water. The water used in the irrigation system is derived from the Stream Bodoeongo, in which sampling was performed monthly for the purpose of obtaining its classification, according to the use in agriculture. Exploratory analyzes were performed using descriptive statistical methods for the hydrodynamic parameters soil. We used geostatistical modeling of classification parameters saline soil (pH, CE and PST), and the spatial and temporal variability were performed by fitting semivariogram models and represented by contour maps and contours, interpolated by ordinary kriging. With the results observed in the study, it was found that the water in the creek Bodoeongo showed high salinity levels being classified thus restricted or improper use in irrigated agriculture. The soil is degraded by salinization process and sodicity, action mainly caused by irrigation with water of lower quality and deficient in natural drainage of the soil. For the practice of irrigated agriculture in the experimental area is recommended the use of artificial drainage with proper management of water and soil.