1. Establishment, Development and Yield of Forage Legumes and Grasses as Cover Crops in Grain Corn in Eastern Canada
2. 3 B. Beck-Friis, B. Linden, and H. Marstorp , 1993 : Nitrogen in crops and soil in cultivation systems with autumn and spring ploughing and with and without catch crops . In: P. Elonen, and J. Pitkanen (eds), Soil Tillage and Environment. Proc. NJF Seminar No. 228, Jokioinen, Finland, 8-10 June, 1993, pp. 133-144. Scandinavian Association of Agricultural Scientists (NJF), Jokioinen, Finland.
3. 4 T. Borggaard , 1988 : Avl af markfro . Det kgl. danske Landhusholdningsselskab, Kopenhagen, Denmark.
4. 5 T. A. Breland, T. Borresen, N. Nilsdotter-Linde, and K. Thorup-Kristensen , 1995 : Catch and cover crops in the future: summary of group work and general discussion . In: B. Linden (ed.), The Use of Catch or Cover Crops to Reduce Leaching and Erosion. Proc. NJF Seminar No. 245, Knivsta, Sweden, 3-4 October, 1994, pp. 264-266. Nordic Association of Agricultural Scientists (NJF), Uppsala, Sweden.