Economic effect of fall vs. spring plowing of forage on following potato production in Prince Edward Island, Canada

Abstract

Fall plowing of forage in a typical barley (Hordeum vulgare L.)–forage–potato (Solanum tuberosum L.) rotation in Prince Edward Island (PEI), Canada has led to negative environmental impacts, including soil erosion and nitrate leaching to groundwater. Data from five locations in PEI during 2009–2016 were assessed to determine the effects of delaying plow‐down of forage from early and late fall to spring on economic returns and risk of returns trade‐offs for potato producers. Factors related to fall or spring plowing such as soil erosion, nitrate leaching, planting date, effect on weeds, insects and diseases, potato harvest loss, and labor constraints were quantified. Potato yields were the same for fall and spring plowing; however, combined data for the five experiments showed late fall plowing was preferred over spring plowing for risk‐averse or neutral potato growers. Risk neutral farmers would require receiving between CAN$229 and $836 ha−1 yr−1, depending on yield loss for spring plowing due to delayed seeding, to be indifferent between fall and spring plowing options. Risk‐averse farmers at all levels of risk aversion would require being paid more than $600 ha−1 yr−1 to be indifferent between fall and spring tillage when 4–6% of yield loss for spring plowing due to delayed planting is assumed. Although spring tillage provides reductions in the risk of soil erosion and nitrate leaching, it also affects production risk and uncertainty. Therefore, we recommend farmers plow forage as late as possible in the autumn and replace it with other conservation tillage practices.