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In 1958 with the co-operation of Quebec Fertilizers Incorporated, and the Quebec Agricultural Research Council; a siol fertility committee under the direction of Dr. H. A. Steppler was formed, at Macdonald College, Quebec. The object of the Macdonald College Soil Fertility Committee was to collect yield data from fertilizer field experiments located on farms in the more agriculturally important areas of Quebec. It was anticipated that this data would provide a realistic evaluation to some of the problems, and to some of the solutions, of fertilizer management in Southwestern Quebec. [...]

[...] The present study is an attempt to determine to what extent oat grain yield response to seeding rates and nitrogen fertilization, can be traced to the reaction of one or more of the yield components. [...]

No description available.

Pyrophosphate retention and half-life values, and pyrophosphatase activity, were determined in 24 organic soil materials containing < 20% ash. Pyrophosphate retention was correlated with ash content (r = 0,876**) but still was weak. Pyrophosphatase activity (11,6 to 148,1 mmol.kg('-1).2h('-1)) was higher in virgin than in cultivated materials and was promoted apparently by nonspecific acid phosphatases. The interaction between water-soluble pyrophosphate and pyrophosphatase activity explained 77% of the variation in log-transformed half-life values ranging from 0,1 to 3,7 days. Copper decreased significantly pyrophosphatase activity. However, pyrophosphate hydrolysis rate was not affected significantly by Cu contents up to 1177 mg.kg('-1) in humic materials. Because of rapid rates of pyrophosphate hydrolysis in humic and mesic materials compared with rate of P uptake by onions, no significant difference in bulb yield and P uptake were obtained at harvest between pyrophosphate and orthophosphate fertilizers.

The effects of added potassium, K, magnesium, Mg and sulfur, S on corn grain and silage yields were investigated in the field for two years. / Due to high nutrient soil, K, Mg and S had no effects on corn grain and silage yields. However, there were trends observed in the treatment effects that were significant. Added K at 240 kg K$ sb2$O/ha increased grain yield over zero kg K$ sb2$O/ha in 1983 and Mg at 60 kg/ha increased grain yield over 30 kg/ha in 1984. In silage, 240 kg K$ sb2$O/ha increased yield over 120 and zero kg K$ sb2$O/ha in 1984. Although there was no K by Mg interaction, there was a need for added Mg to achieve higher yields. / The cumulative effect of fertilizer S at 50 kg/ha significantly reduced silage yield in 1984 over zero S treatment indicating that fertilizer S was unnecessary for corn growth by reason of high levels of soil S and sufficient S provided from precipitation and air dry deposition. S had no interaction with K and Mg because there was no need for fertilizer S to increase yields. / The antagonistic association between K and Mg was seen at the seedling, tasseling and silking stages. / There was an indication of a K by S interaction which was expressed at different stages of growth, but this effect was not evident for dry matter yields.

An experiment was conducted for two years to determine the effect of seeding rate, and nitrogen fertility on the yield and quality of hard red spring wheat (Triticum aestivum L.) in Quebec. The experiment was conducted on a Ste-Rosalie series soil (humic gleysol), in the St-Hyacinthe region, 50 km east of Montreal. The design of the experiment was a split-plot design. The treatments in the main plots were the plant densities while the nitrogen treatments (rate of nitrogen, number and timing of the applications and formulation of fertilizer nitrogen) were applied to the sub-plots. Nitrogen had a significant effect on yields in 1987, but not in 1986. Maximum yield was 6838 kg ha$ sp{-1}$ in 1986 and 3807 kg ha$ sp{-1}$ in 1987. Protein concentration was increased by higher nitrogen rates in both years. The yield and protein concentration were affected by low precipitation in 1987. Applying the nitrogen later in the season increased the protein concentration in both seasons. It also decreased yield in 1987, but this was caused by lack of water in late June and July 1987. Formulation of nitrogen fertilizer did not have an effect on yield and protein content of the crop.

Sorghum is considered to be of African origin and subsequently spread to most countries in tropical and subtropical regions. Sorghum has outstanding resistance against drought conditions. Grain and fodder from sorghum plants have been used for man's and animals' consumption respectively for many decades. Experiments were conducted on Yasothon soil series (Oxic Paleustults) in Northeast Thailand, this is considered a poor soil. Growth parameters of sorghum were affected most by nitrogen chemical fertiliser followed by potassium chemical fertiliser. An increase in nitrogen level increased growth parameters and seed yields/ha of the sorghum plants whilst an increase in potassium also increased growth parameters and seed yields but to a lesser extent. High application rates of both nitrogen and potassium were required to achieve high total dry weights and seed yields/ha. Fermented cattle manure significantly increased growth parameters of the sorghum plants and soil properties. were also improved by cattle manure. Total dry weights and seed yields/ha were affected most by seasons and treatments whilst seasons x treatments had highly significant effects on seed yields/ha but not total dry weights/ha. In terms of economic viewpoint, optimum application rates for nitrogen at a range of 300-450 kg N/ha and 100 kg K20/ha for potassium plus 40 tonnes/ha of fermented cattle manure were the recommended rates for optimum above ground total dry weight (15,940-26,282 kg/ha) and seed yield (5,047- 6,374 kg/ha) of IS 23585 forage sorghum cultivar on Yasothon soil series. An increase in nitrogen fertiliser application increased estimated crude protein (CP) of the sorghum plants whilst potassium did not. Both nitrogen and potassium had no Significant effects on acid detergent fibre (ADF), neutral detergent fibre (NDF), and dry matter degradability (DMO). However, seasons had significant effects on CP, NDF, ADF, DMD and brix values. Treatments also had significant effects on all components except DMD, and brix values. Seasons x treatments had significant effects on all components except CP and brix values.

Graduation date: 1983

Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1984. / Bibliography: leaves [171]-179. / Microfilm. / xv, 179 leaves, bound ill. 29 cm