1. Dep. of Soil Science University of Manitoba 362 Ellis Bldg Winnipeg MB Canada R3T 2N2
2. Agriculture and Agri-Food Canada P.O. Box 1000A, RR #3 Brandon MB Canada R7A 5Y3
3. Western Co-operative Fertilizers Limited P.O. Box 2500 Calgary AB Canada T2P 2N1
4. Dep. of Plant Science University of Manitoba Winnipeg MB Canada R3T 2N2