Infiltration into Cropped Soils: Effect of Rain and Sodium Adsorption Ratio–Impacted Irrigation Water

Abstract

Th e sodium adsorption ratio (SAR) and salinity criteria for water suitability for irrigation have been developed for conditions where irrigation water is the only water source. It is not clear that these criteria are applicable to environments where there is a combination of rain and irrigation during the growing season. Th e interaction of rainfall with irrigation water is expected to result in increased sodicity hazard because of the low electrical conductivity of rain. In this study we examined the eff ects of irrigation waters of SAR 2, 4, 6, 8, and 10 mmol 1/2 L −1/2 and electrical conductivities of 1 and 2 dS m −1 on the infi ltration rate of two soils with alternating cycles of rain (simulated with a rainfall sprinkler) and irrigation water, separated by drying cycles. Th e infi ltration rate of surface samples from two soils, Kobase silty clay (fi ne, smectitic, frigid, Torrertic Haplustept) and Glendive very fi ne sandy loam (coarse-loamy, mixed superactive, calcareous, frigid Aridic Ustifl uvent) were evaluated under alfalfa (Medicago sativa) cropped conditions for over 140 d and under full canopy cover. Reductions in infi ltration were observed for both soils for SAR above 2, and the reductions became more severe with increasing SAR. Saturated hydraulic conductivity measurements taken from undisturbed cores at the end of the experiment were highly variable, suggesting that in situ infi ltration measurements may be preferred when evaluating SAR eff ects. ) is a good estimator of the exchangeable sodium percentage (ESP) (U.S. Salinity Laboratory Staff , 1954) and has been used to develop numerous water quality criteria for irrigation (Ayers and Westcot, 1985). For a given SAR value, the adverse impacts on soil physical properties are reduced with increasing salinity (Ayers and Westcot, 1985), commonly reported as the EC in dS m −1 (electrical conductivity of the solution). Infi ltration intoTh ere are many studies documenting the adverse eff ects of sodicity on soil hydraulic properties, mostly saturated hydraulic conductivity (K s ) in packed columns run for short periods of time under continuous water fl ow. McNeal and others (McNeal and Coleman, 1966;McNeal et al., , 1969McNeal, 1968) characterized the eff ects of EC and SAR on soil K s and soil swelling. Th ey observed a range in soil stability for arid land soils of the southwestern USA. Th ey concluded that soils high in kaolinite and sesquioxides seemed to be more stable and soils high in smectite the least stable . Frenkel et al. (1978) examined the saturated K s of several soils of varying mineralogy as related to their response to diff erent EC-SAR levels. Th e soil with kaolinitic clay was the most stable, followed by the soil with vermiculitic clay, and the smectitic clay soils were the most sensitive to SAR. However, these experiments lack data below SAR 10 and provide no information in the salinity range between EC = 1 dS m −1 and deionized water. Th ere are only a few studies where dilute waters were applied and infi ltration or K s mea...

Effect of soil and water characteristics on yield and properties of ‘Spunta’ potatoes

“…SAR is a measure of the sodicity of soil, as determined from analysis of water extracted from the soil. The formula for calculating SAR is (Suarez et al, 2008):…”

Clogging Mechanism of Stormwater Filter Media by NaCl as a Deicing Salt

“…Electrokinetic phenomena and effects on pore structure and flow Suarez et al (2008) investigated the reduction of infiltration rate into cropped soils and concluded that an increase in the sodium adsorption ratio (SAR) caused changes in pore structure, eventually reducing the infiltration capacity. The SAR is calculated as follows:…”

“…Adsorption of sodium and release of calcium and magnesium (due to salt application) resulted in a substantial increase of the sodium adsorption ratio. Suarez et al (2008) suggested that an FIG. 5.…”

“…Some studies have also focused on the effect of deicing salts (sodium chloride) in reducing the pollutant removal capacity of SFM (Amrhein et al, 1992(Amrhein et al, , 1993Blecken et al, 2011;Paus et al, 2014;Søberg et al, 2014). Suarez et al (2006Suarez et al ( , 2008 focused on the impacts of saltladen water on agricultural soils and permeability, while Denich et al (2013) studied the reduction of hydraulic conductivity of the SFM due to application of deicing salts, focusing on the chemistry of the effluent and media. Both research groups concluded that chemical reactions adversely changed the pore structure of the SFM; however, they did not measure the pore structure using any experimental methods.…”

Groundwater stress and vulnerability in rural coastal aquifers under competing demands: a case study from Sri Lanka

“…To investigate the infiltration qualities of the soil, sodium adsorption ratio (SAR) and electrical conductivity (EC) data were analyzed. Typically, EC to SAR ratio is a good indicator of the infiltration capacity of the soil (Suarez et al 2008); http://waterquality.montana.edu/docs/methane/ basics_highlight.shtml, accessed 26 July 2009). Figure 9 shows the relationship between salinity as EC, sodicity as SAR, and infiltration rates.…”