Increasing potato profitability through rotation systems and winter cover, nitrogen fertilizer, and supplemental irrigation in Atlantic Canada

Abstract

Average potato yield in Prince Edward Island, Canada, has been stagnant since 2006. Two field studies were conducted on Charlottetown fine sandy loam soil to address this concern. In the first experiment, two alternative crop rotations, grain corn (Zea mays L.)–sorghum sudan grass (Sorghum × drummondii)–potato (C–SS–P) and soybean (Glycine max (L.) Merr.)–mustard (Brassica juncea (L.) Czern.)–potato (Soy–M–P), were compared to a conventional barley (Hordeum jubatum L.) (under seeded with red clover)–red clover (Trifolium pratense L.)–potato (Solanum tuberosum L.) (B–RedCl–P) rotation. This experiment was conducted for two 3-year cycles comparing the effects of potato rotation, nitrogen fertilizer, and supplemental irrigation. The second experiment evaluated the inclusion of winter cover crops in a 3-year potato crop rotation. The profitability of potatoes in each rotation was assessed using a stochastic budget of yields and fertilizer and crop prices. The effects of supplemental irrigation were not significant; however, nitrogen fertilization increased potato yields by 48%. Potato yields and net revenues in C–SS–P increased by 10.5% and 32.6% and in Soy–M–P by 6.7% and 20.5%, respectively, compared to potato in B–RedCl–P rotation. The use of winter rape cover increased potato yields by 18.6% compared to a system without winter covers, although some of these increases could be due to the use of sudan grass instead of red clover in B–RedCl–P rotation. It is recommended that potato producers implement the alternative rotation with additional fertilization and winter cover crops to increase yields and profits.