Articles
INTERRELATIONS BETWEEN WATER AND SOIL CHARACTERISTICS IN TRICKLE IRRIGATION MANAGEMENT: AN EXPERIMENTAL APPROACH
Article number
646_18
Pages
147 – 153
Language
English
Abstract
An attempt has been made to relate the amount of water applied by trickle irrigation to the salinity of the soil solution with a view to determining how much water may be applied before leaching is required.
The following approach was developed: 1) For each specific water and soil combination a functional leaching requirement (FLR) is defined as the inverse of the number of times (1/n) that a certain irrigation quota (IQ) may be applied consecutively until leaching is required to control total soil salinity or any of its components; 2) The value of n is found experimentally by analysing the saturation extract of a soil, whose initial conditions are known, by evaporating in a microwave oven after increasing number of IQs of a certain irrigation water have been applied.
This approach was tried regionally in 40 combinations of 5 soils and 8 waters and their FLR were compared with a theoretical expected LR calculated as the simple consequence of concentration, without any provision for changes in chemical composition during the process.
The results show that in some water-soil combinations the FLR may differ significatively from the theoretical LR for total salinity and soluble boron content.
The influence on n on the relation between the IQ and the percentage of water saturation (%Ws) and of the relation between %Ws and Field Capacity on the interpretation criteria are discussed.
The following approach was developed: 1) For each specific water and soil combination a functional leaching requirement (FLR) is defined as the inverse of the number of times (1/n) that a certain irrigation quota (IQ) may be applied consecutively until leaching is required to control total soil salinity or any of its components; 2) The value of n is found experimentally by analysing the saturation extract of a soil, whose initial conditions are known, by evaporating in a microwave oven after increasing number of IQs of a certain irrigation water have been applied.
This approach was tried regionally in 40 combinations of 5 soils and 8 waters and their FLR were compared with a theoretical expected LR calculated as the simple consequence of concentration, without any provision for changes in chemical composition during the process.
The results show that in some water-soil combinations the FLR may differ significatively from the theoretical LR for total salinity and soluble boron content.
The influence on n on the relation between the IQ and the percentage of water saturation (%Ws) and of the relation between %Ws and Field Capacity on the interpretation criteria are discussed.
Authors
J.A. Maffei, L. Nijensohn, L. Rodríguez-Plaza
Keywords
water quality, irrigation quota, leaching requirement, saturation percentage, boron, salinity
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