THE EFFECTS OF NITROGEN, ROW SPACING AND SEEDING RATE ON THE YIELD OFFLAX UNDER A ZERO-TILL PRODUCTION SYSTEM

The long-term sustainability of agriculture requires that soil degrada tion be addressed and that crop production systems that incorporate th e benefits of surface residues and standing stubble through conservati on tillage practices be evaluated critically. The objective was to stu dy the effects of nitrogen, row spacing and seeding rate on the yield of flax (Linum usitatissimum L.) under zero-till production practices. Three row spacings, six seeding rates and two rates of nitrogen were investigated. The plots were directly seeded into barley stubble under a continuous cropping zero-till production system. When yield levels were > 1200 kg ha-1, yields were not significantly affected by row spa cing, but when yield levels were < 1200 kg ha-1, the 20-cm row spacing was favored over the 10- or 30-cm spacings. Yields increased linearly with increase in seeding rate at all row spacings. There were no inte ractions observed between nitrogen, row spacing and seeding rate. The results of this study have important implications in terms of equipmen t design, cost for zero-till seeding equipment, and the opportunity to easily modify existing equipment for zero-till seeding.