Establishment of winter versus spring aerial seedings of domestic grasses and legumes on logged sites

Abstract

Forage grasses and legumes were sown on clearcut-logged sites near Kamloops, B.C., to increase range productivity in the interval before the forest canopy closed. Seed was broadcast by aeroplane during the winter when these sites were snow-covered. On clearcuts above 1,000 m elevation 5 species were used: orchardgrass (Dactylis glomerata L.), timothy (Phleum pratense L.), smooth brome (Bromus intermis Leyss.), alsike clover (Trifolium hybridum L.), and white clover (T. repens L.). The objective of this study was to determine the effect of seeding date on the establishment and survival of these grasses and legumes. A survey of existing operational winter seedings produced establishment estimates (percent of live seeds sown that resulted in established plants) for orchardgrass of 2.3%; timothy, 1.2%; and brome, 1.3%; in contrast to 0.1% for the clover species. On operational spring seedings grass establishment was 1.3, 0.5, and 1.9% respectively for the first 3 species while clover was 2.6%. In a date-of-seeding trial, hand-seeded on a new clearcut, first and second year clover plant establishment averaged 1.5 and 0.2% respectively for 4 winter seedings (November 11 to March 22) compared to 18.3 and 13.2% for a May seeding. First and second year establishment of orchardgrass in winter seedings was 42.1 and 21.9% compared to 35.6 and 12% for the May seeding. These results indicate that while broadcast seeding on snow-covered high elevation clearcuts resulted in successful establishment of some grasses, it was ineffective for establishment of alsike and white clover.