Articles
An electronic decision support system to assess risk-based, site-specific fitness for use of irrigation water: application to horticultural crops
Article number
1409_30
Pages
223 – 230
Language
English
Abstract
Increased demands on available irrigation water supplies necessitate increased production with less water, often of a poorer quality and from unconventional sources.
An electronic decision support system (DSS) which models soil-plant-atmosphere interactions has been developed to assess the fitness for use (FFU) of irrigation waters under site-specific conditions that may influence the assessment.
The DSS operates at two tiers to assess the effect that water quality constituents may have on soil quality, crop yield and quality, and irrigation infrastructure. ‘Suitability Indicators’ divide these effects further into sub-components.
User-friendly colour coded Tier 2 output displays the risk associated with using the water under specific conditions, as ‘ideal’, ‘acceptable’, ‘tolerable’ or ‘unacceptable’. Tier 1 assessments provide generic, conservative guidance, assuming no dilution of irrigation water by rain, instant equilibrium between water constituents and soil, and crops that are generally sensitive to water quality constituents.
This resembles currently published international guidelines.
Tier 2 assessments are more rigorous and used to determine whether the assessed FFU of a water could improve when site-specific conditions are considered.
These assessments use the soil water balance (SWB) model to dynamically simulate the interactions between irrigation water constituents and the soil-crop-atmosphere system over 10 to 45 years, to quantify the probability and severity of a specific effect occurring.
Default model parameters enable selection of an appropriate weather station, soil texture, crop species, irrigation management approach, and irrigation system.
DSS predicted yield response to salinity is demonstrated for three horticultural crops to be comparable to that of international irrigation water quality guidelines, under similar conditions and assumptions.
Examples are given to illustrate how FFU of irrigation water is affected by site-specific conditions.
This illustrates how the DSS can be used to identify conditions under which a particular water can be used most beneficially.
An electronic decision support system (DSS) which models soil-plant-atmosphere interactions has been developed to assess the fitness for use (FFU) of irrigation waters under site-specific conditions that may influence the assessment.
The DSS operates at two tiers to assess the effect that water quality constituents may have on soil quality, crop yield and quality, and irrigation infrastructure. ‘Suitability Indicators’ divide these effects further into sub-components.
User-friendly colour coded Tier 2 output displays the risk associated with using the water under specific conditions, as ‘ideal’, ‘acceptable’, ‘tolerable’ or ‘unacceptable’. Tier 1 assessments provide generic, conservative guidance, assuming no dilution of irrigation water by rain, instant equilibrium between water constituents and soil, and crops that are generally sensitive to water quality constituents.
This resembles currently published international guidelines.
Tier 2 assessments are more rigorous and used to determine whether the assessed FFU of a water could improve when site-specific conditions are considered.
These assessments use the soil water balance (SWB) model to dynamically simulate the interactions between irrigation water constituents and the soil-crop-atmosphere system over 10 to 45 years, to quantify the probability and severity of a specific effect occurring.
Default model parameters enable selection of an appropriate weather station, soil texture, crop species, irrigation management approach, and irrigation system.
DSS predicted yield response to salinity is demonstrated for three horticultural crops to be comparable to that of international irrigation water quality guidelines, under similar conditions and assumptions.
Examples are given to illustrate how FFU of irrigation water is affected by site-specific conditions.
This illustrates how the DSS can be used to identify conditions under which a particular water can be used most beneficially.
Authors
J.G. Annandale, H.M. du Plessis, N. Benade, N.J. Taylor
Keywords
irrigation water quality guidelines, crop quality, crop yield, soil quality, corrosion and scaling of irrigation infrastructure, salinity, sodicity
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