Use of linear regression to estimate the relationship between electrical conductivity and ionic composition of irrigation water

Revista Brasileira de Engenharia Agrícola e Ambiental

Maia, Celsemy E.¹  Medeiros, José F. de¹  Ribeiro, Giorgio M.¹ 

[1]Escola Superior de Agricultura de Mossoró

关键词: water quality;    salinity;    model identity test    INTRODUÇÃO A irrigação consiste em fornecer água às culturas quando não dispõem de quantidade suficiente para suprir suas necessidades;    porém todo cuidado deve ser tomado quando se fizer uso da irrigação;    pois alguns inconvenientes podem surgir;    como a salinização;    um dos principais problemas enfrentados devido;    principalmente;    à qualidade da água de irrigação e/ou ao manejo inadequado (Pizzarro;    1978;    Servant;    1980);   

DOI  :  10.1590/S1415-43662005000100003

学科分类：农业科学（综合）

来源: Universidade Federal de Campina Grande * Centro de Ciencias e Tecnologia

【 摘 要 】

Several studies have been accomplished lately to evaluate irrigation water quality in the semi-arid region of the Northeast Brazil. In some of these studies, the authors have adjusted some chemical characteristics such as calcium, magnesium, sodium, chloride and sum of cations as a function of electrical conductivity (EC) through empirical equations, however attention should be given to temporal and spatial variations. In this paper, the influence of water source, time of sampling, and soil type in the linear regression determination of electrical conductivity as a function of the ions present in the irrigation water was evaluated. A 562-analysis database originated from 55 rural properties was utilized. The water samples were analyzed for pH, EC, Ca2+, Mg2+, Na+, K+, Cl-, HCO3-, CO32- , and SO42-. From January 1988 samplings in the properties were made during 411 days. The database was divided into 14 sampling times, three sources (well, river, and dam), and 10 soil types. For comparing the adjusted equations an identity model test was utilized. The adjusted linear equations with electrical conductivity as a function of the contents of calcium, magnesium, potassium, sodium, chloride, bicarbonate, carbonate, and sulfate varied significantly with time of sampling, water source, and soil type.

【 授权许可】

CC BY-NC