Rate of gain, efficiency of food utilization, and nitrogen retention by weanling rats were used as criteria to determine the nutritive value of wheat grown on a sulphur-deficient Grey Wooded soil. All diets were supplemented with minerals, vitamins, and lysine. Grain from an area continuously cropped to wheat-fallow and from an area cropped to a 5-year grain-legume rotation were compared. On Breton loam, a Grey Wooded soil, grain is highly responsive to fertilization with nitrogen; and legumes are very highly responsive to sulphur fertilization. Samples were fed from plots receiving the same fertilizer treatments in each cropping system. Fertilizer treatments and cropping systems both caused occasional significant differences, and were associated with some consistent trends for differences, in nutritive value of wheat. In general, the grain was of substantially superior nutritive value when grown following legumes; in one year these differences tended to be greater with fertilizer treatments which increased yields. During the same year fertilization with manure tended to improve the nutritive value of fallow wheat. The animal growth and food efficiency were closely related to the protein content of the foods. There were differences between results obtained in 2 successive years. While the differences may have been due to the effect of seasons or to the biennial application of fertilizers they appeared to be closely related to protein content of the grain, a characteristic which long-time data have shown to be highly variable in grain from the Breton plots.

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Irrigation of legume and nonlegume forage species with municipal waste water at rates designed to approximate and double the net evapotranspiration minus precipitation deficit was studied for 11 yr at Taber, Alberta, Canada. The soil was a Brown Chernozemic Cavendish loamy sand (Aridic Haploboroll). Reed canarygrass required additional N to give yields similar to those of the alfalfa (Medicago sativaL.). Alfalfa yields were not greatly affected by increasing levels of N and P fertilizer or by the application of excess wastewater. The N uptake by reed canarygrass (Phalaris arundinaceaL.) was considerably less than that of alfalfa when the N supply was limited, but about the same when the N supply was adequate. Reed canarygrass recovered nearly 50% of applied fertilizer 15N over 2 yr with about 80% of total uptake in the first cutting after N application. Alfalfa only recovered 24% of applied N at low irrigation rates and 14% at the higher rate. Estimates of fertilizer N uptake based on the increase in N yield of reed canarygrass due to fertilization would have been much higher. About 25% of the fertilizer N remained in the soil after two irrigation seasons, independent of forage species or irrigation rate. Sixty percent of that N remained in the surface 15 cm. Losses of N from alfalfa were nearly double those from reed canarygrass plots. Wastewater irrigation did not lead to levels of any element phytotoxic to plants or harmful to animals consuming the forage and probably increased the nutritional quality of the forage.

The triethanolamine — BaCl2 (pH 8.1), 1N NH4C2H3O2 (pH 7 and 4.8), 1N Ba(C2H3O2)2 (pH 7) and unbuffered 1N KCl methods for evaluating total exchange acidity in soils were compared. The general order of extracting ability was found to be triethanolamine — BaCl2 (pH 8.1 > 1N NH4C2H3O2 (pH 7) = 1N Ba(C2H3O2)2 (pH 7) > 1N KCl for kaolinite clays and organic matter where variations in results were largely attributable to the exchange acidity held by charges from pH-dependent exchange sites. Although less pronounced, the general order of extracting ability for montmorillonites, where most of the exchange acidity is held by charges from permanent exchange sites, was found to be triethanolamine — BaCl2 pH 8.1) > 1N KCl > 1N NH4C2H3O2 (pH 7) = 1N Ba(C2H3O2)2 (pH 7). Only the triethanolamine-BaCl2 method gave substantially higher results for illite clays.All solutions, with the exception of 1N NH4C2H3O2 (pH 4.8), removed only small portions of exchangeable aluminium from the materials studied although equivalent amounts of hydrogen were released. The 1N NH4C2H3O2 (pH 4.8) method was the best technique tested for removal of exchangeable aluminium although its suitability remains somewhat doubtful.Variations in the quantitative amounts of exchange acidity found by different methods in some common Alberta soils can be explained by inferences made from the results obtained for the standard samples of known competition.