EFFECTS OF ROTATION AND FERTILIZATION ON ECONOMICS OF CROP PRODUCTION IN THE BLACK SOIL ZONE OF NORTH-CENTRAL SASKATCHEWAN

Abstract

Effects of changes in product prices and input costs on the economic performance of 10 spring wheat (Triticum aestivum L.) -based rotations grown on a highly fertile orthic Black Chernozemic silty clay loam soil at Melfort, Saskatchewan, were examined over the 27-yr period from 1960–1986. The rotations differed in frequency of summerfallow, N and P fertilization, and cropping sequence involving canola (Brassica napus L.), grass-legume hay [bromegrass (Bromus inermis Leyss.), alfalfa (Medicago sativa L.)], and legume green manure [sweetclover (Melilotus officinalis (L.) Lam)]. During 1960–1971 fertilized rotations received the generally recommended rates of N and P for the region, but during 1972–1986, fertilizer was applied based on soil tests. Net income, riskiness, and costs of production were calculated over a range of product prices and input costs. At wheat prices greater than $147 t−1, fertilized fallow-wheat-wheat (F-W-W), fertilized fallow-canola-wheat (F-C-W), and a 6-yr fertilized grass-legume hay (H) rotation (F-W-W-H-H-W), generally provided the best overall economic return. At lower wheat prices, unfertilized F-W-W and F-W-W-H-H-W and fertilized fallow-wheat (F-W) often provided net income similar to the above rotations. It was profitable to substitute canola for wheat grown on conventional fallow, or on partial fallow after grass-legume hay, when the ratio of canola to wheat price was greater than about 2.0. Similarly, it was profitable to include grass-legume hay in wheat rotations when the hay price was greater than one-half that of wheat. Continuous wheat and sweetclover green manure-wheat-wheat (Gm-W-W) were not economically competitive with the best rotations at any of the price options examined. Fertilizer application was profitable in F-W-W and continuous wheat when the ratio of fertilizer cost to wheat price was less than about 5.0; it was profitable in F-W-W-H-H-W when this ratio was less than 3.5. The cost of producing wheat increased directly with rotation length. Income variability and frequency of economic losses increased with cropping intensity; however, all-risk crop insurance was effective in minimizing financial risk.Key words: Wheat (spring), canola, hay, net income, costs, riskiness