Browsing by Author "Rostad, H.P.W."
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Item Acid soils in west-central Saskatchewan(1981-02-16) Rostad, H.P.W.Item The effect of seed-applied nitrogen on different crops(1995-02-23) Rostad, H.P.W.; Henry, J.L.; Krug, P.M.; Xu, F.Item Liming acid soils in west central Saskatchewan(1987-02-19) de Gooijer, H.C.; Rostad, H.P.W.; Krug, P.M.Item Seasonal variation of wind erodibility of Saskatchewan soils(1991-02-21) Hilliard, C.R.; Rostad, H.P.W.Item Soil erosion rates in west central Saskatchewan(1986-02-20) Kiss, J.J.; de Jong, E.; Rostad, H.P.W.Soil erosion trends and rates in five Rural Municipalities (RMs) of west central Saskatchewan are assessed using Cesium-137 as an indicator of soil redistribution within the landscape. The study area is located around Unity, and includes the RMs of Reford, Tramping Lake, Grass Lake, Buffalo, and Round Valley. Native, non-eroded soils across the study area were sampled and analyzed for Cesium-137 to determine a baseline value for non-eroded soils (2877 Bq-2) which was used to predict erosion rates on cultivated soils since the early 1960's. Cultivated hillslopes across the area were also sampled for Cesium-137 redistribution and the Cesium-137 values compared to the non-eroded baseline value. Mean hillslope soil erosion rates were estimated as 23 +/- 8 tonnes ha-1 yr-1 for 0-3 % gradient class, 27 +/- 9 tonnes ha-1 yr-1 for 3-10 % gradient class, and 48 +/-16 tonnes ha-1 yr-1 for >10 % gradient class, representing a soil removal of 3.8, 4.4, and 7.8 cm respectively since 1960. These soil losses represent between 27 and 64 % of the topsoil and between 7 and 30 % of the solum present within the eroding upslope areas today. These erosion rates occur over approximately 2/3 of the cultivated study area. High rates of soil erosion over such a large portion of the landscape are alarming, considering that the accepted tolerable soil loss is 11.2 to 4.5 tonnes ha-1 yr-1 (Wischmeier and Smith,1978). Long-term average wind (WEE) and water (USLE) erosion estimates did not equal the Cesium-137 erosion rates.Item Stabilization of wind erodible loamy sands by an oil production waste sludge(1995-02-23) Rasiah, V.; Biederbeck, V.O.; Rostad, H.P.W.A field experiment was conducted to determine the effectiveness of production oily waste sludges as stabilizers of wind erodible fraction, WEF (material < 0.84 mm), of sandy loams and to determine the persistence of stabilized fractions during cultivation. The waste sludge application resulted in 5 replicated soil oil contents, 0, 1.05, 1.45, 3.0, and 7.0% (by weight). Dry aggregate size distribution, DASD, determinations were carried out twice an year for five consecutive years. The soil oil content had significant influence on the temporal changes in both WEF and DASD. The amount of WEF that was stabilized by the sludge increased with soil oil content (R2 = 0.88). Similar trends were observed for aggregates > 0.84 mm and < 34 mm. Depending on the soil oil content, the potential maximum amount of WEF stabilized into aggregates > 0.84 mm ranged from 41 to 63% (R2 = 0.93). The half-life for destabilization of the stabilized WEF was 2 yr. The re-sieving data indicated that mechanical stress enhanced fragmentation of stabilized aggregates.Item Surface pH of Saskatchewan soils(1983-02-14) Rostad, H.P.W.; Kiss, J.J.; Anderson, A.J.