ALBERT

Description: A good statistical relationship was obtained between the exchangeable-sodium ratio and the sodium adsorption ratio (SAR) in Brown Solonetzic and associated soils in southern Alberta. Reliable estimates of the exchangeable-sodium status of these sulfate-rich soils may be anticipated when SAR values are less than 20. Prediction of the exchangeable-sodium status of soils on the basis of SAR values is preferable for both Solonetzic soil and irrigation suitability classification. A saturation extract SAR value of five in the B horizon generally corresponds to an exchangeable calcium to sodium ratio of 10. Saturation extract SAR values of five and 12 are recommended as revised soil chemical criteria for Brown Solonetzic soil and irrigation suitability classification, respectively. Key words: Solonetzic soils, exchangeable cations, sodium adsorption ratio, selectivity coefficient, irrigation suitability

Description: We conducted a greenhouse study on large, semi-disturbed soil cores excavated from the vicinity of Verdigris Lake in southern Alberta to assess the suitability of different saline-sodic waters for irrigation. Soil salinization and sodication, surface soil physical properties, and yield of five soft white spring wheat crops (Triticum aestivum L. var. AC Reed) were examined under alternate applications of simulated rain with saline-sodic irrigation waters ranging from "safe" to "potentially hazardous" for irrigation. Increased salinity and sodicity of irrigation waters alternated with simulated rain resulted in increased salinity and sodicity in the upper 0.60 to 0.90 m of the soil. Salt accumulation in the root zone decreased as the leaching fraction increased. Aggregate stability and infiltration properties of the soil were generally adversely affected by the more saline and sodic irrigation waters. Infiltration properties were significantly greater with irrigation water (IW) than with distilled water (DW). The soil infiltration rate at 2 h, with DW as the infiltrating water, was the most sensitive soil physical property for assessment of irrigation water suitability. The infiltration test after five crop cycles gave a better indication of the effects of excess sodicity of irrigation water on soil structural stability than the aggregate stability test. The cumulative effects of long-term supplemental irrigation with saline-sodic waters on soil chemical and physical properties need to be considered when assessing irrigation water suitability. Irrigation waters with electrical conductivity (EC) less than or equal to 1 dS m-1 and a sodium adsorption ratio (SAR) less than or equal to 5 did not result in deterioration of soil physical properties and were considered "safe" for supplemental irrigation of the Masinasin soil. Alternate applications of irrigation and distilled water should be used to evaluate soil infiltration rates and the structural stability of soils to which saline-sodic waters are to be applied. Key words: Saline-sodic irrigation water, soil salinity, soil sodicity, aggregate stability, infiltration, water quali

Description: A 4-yr study was conducted on irrigated Solonetzic and Chernozemic soils in the Berry Creek Basin of east-central Alberta to assess changes in soil salinity and sodicity during irrigated alfalfa production and to evaluate the suitability of Solonetzic soils for irrigation. Two of the study sites consisted mainly of soils classified as Solodized Solonetz, with at least 70% in the Solonetzic order. Two chernozemic sites were almost exclusively Chernozemic soils. A significant increase in soil salinity occurred in the A horizon at one solonetzic site and at both chernozemic sites and in the B horizon of one chernozemic site. Mean electrical conductivity (ECe) in these horizons for all irrigation treatments was less than or equal to 1 dS m−1. Soil sodicity also increased significantly in the A horizon at one solonetzic site, and in the A and B horizons of both chernozemic sites. The mean sodium adsorption ratio (SAR) of the A horizon at this solonetzic site was 2.9, 4.8, 4.4 and 5.0 for the control, low, medium and high irrigation treatments, respectively. The SAR in the A horizon at the chernozemic sites was less than 2.6 for all the irrigation treatments. Increases in soil salinity and sodicity were attributed to the chemistry and amount of irrigation water used at each site. Salinization and sodification in addition to the changes associated with the quality and quantity of irrigation water were not evident at any of the sites. The two-cut yield of alfalfa from the solonetzic sites in the third year of growth was about 25% less than from the chernozemic sites and was below the acceptable yield range for irrigated alfalfa in southern Alberta. Our results confirm existing land classification standards in Alberta that exclude solonetzic landscapes from irrigation development where more than about 30% of the soils have an SAR value greater than 12 in any soil horizon within 1 m of the surface. Key words: Solonetzic soils, irrigation suitability, soil salinity, soil sodicity, irrigated alfalfa

Description: A combination of field and laboratory procedures was used to estimate moisture-retention parameters of four coarse-textured soil series in southern Alberta. In situ field capacity moisture content was substantially higher than estimates based on conventional laboratory methods, resulting in significant underestimation of total available moisture. Moisture-retention capacity of all four soil series was found to be adequate for irrigation development. Empirical equations were developed to estimate the upper and lower limits of moisture retention on the basis of particle-size distribution, as determined by the Bouyoucos hydrometer method. Five alternative empirical methods were also evaluated for use in predicting moisture-retention parameters of coarse-textured soils. Equations presented by Rawls et al. (1982) were found to have the best relationship with southern Alberta data for both field capacity and wilting point. Key words: Coarse-textured soils, moisture-retention parameters, particle-size distribution, empirical models, irrigation suitability

Description: A 5-yr study was conducted in the County of Newell to monitor soil salinity and sodicity, water-table levels and crop production on Solonetzic soil associations under normal irrigation management practices. All soil associations consisted of at least 50 percent Solonetzic Order soils, with Brown Solod as the dominant subgroup at all but one site. Changes in soil quality were monitored through regular measurements of water-table levels, annual fall sampling and chemical analysis of soils. Irrigation practises used by farmers did not permanently raise water-table levels at any of the sites irrigated by center pivots. Changes in soil salinity or sodicity as a result of irrigation were generally not statistically significant, suggesting that the salt status of soils at most sites did not change appreciably over the 5-yr period. The relatively low productive capability of land units dominated by Solonetzic soils was evident in the low yield and by a high degree of variability in yield within individual sites. Careful irrigation management partially compensated for some of the soil limitations in these Solonetzic soil landscapes; however, due to the low productivity observed, modification of existing land classification standards to allow irrigation of Solonetzic soils is not presently recommended. Key words: Irrigation suitability, Solonetzic soils, productive capability

Description: A shallow subsurface drainage system effectively controlled a high water table and reduced salinity in an irrigated soil near Magrath, Alberta. Plastic corrugated tubing was installed in 1976 at depths of 1.1–1.5 m and spacings of 15 and 30 m in a moderately saline soil. During the irrigation period, the water table rose to within 0.3 m of the surface but was lowered to pre-irrigation levels within 48 h. The water table was maintained at, or below, the depth of the drains between irrigations. The 15- and 30-m spacings of the drain lines were equally effective in providing water table control in this lacustrine soil which was underlain by a coarse sand and gravel layer. Salinity levels were decreased substantially only within the surface 0.3-m soil depth. Quality of the drainage effluent remained constant throughout the growing season with only small dilution effects detected during irrigations. Barley yields increased to 3900 kg/ha in 1978, 2 yr following drainage of this saline soil which had been out of crop production for 20 yr.

Description: The risk of P leaching increases on land that receives manure at rates sufficient to meet crop N requirements, but calcareous subsoils may minimize P loss due to P adsorption. An 8-yr field experiment was conducted to determine the effects of different rates of manure on the accumulation and leaching of soil P in a coarse-textured (CT) soil and a medium-textured (MT) soil under typical irrigation management in southern Alberta. Treatments included a non-manured control and four rates of cattle (Bos taurus) manure (20, 40, 60, and 120 Mg ha-1 yr-1, wet-weight basis). In manured treatments, P addition ranged from about 80 to 450 kg P ha-1 yr-1, while P removal by annual cereal silage crops ranged from 15 to 22 kg P ha-1 yr-1. High soil test P (STP) concentrations occurred to a depth of 0.6 m at the CT site and 0.3 m at the MT site. Increase in STP concentration to 0.6 m was equivalent to 43% of net P input, and increase in total soil P was equivalent to 78% of net P input. Non-recovery of net P input suggests that P loss by leaching occurred at these sites and that leaching was more prevalent at the CT site. These calcareous soils have considerable potential to hold surplus P, but may still allow P leaching.Key words: Manure, phosphorus dynamics, soil test phosphorus, phosphorus leaching, soil texture