Profitability of abrasive weeding in organic grain and vegetable crops

Weed competition, especially within the crop row, limits the productivity and profitability of organic crop production. Abrasive weeding, a mechanical alternative to hand weeding, uses air-propelled grits to control small weed seedlings growing within the crop row. Recent research has demonstrated the successful use of abrasive weeding to reduce weed competition and increase yields in organic maize ( Zea mays ), tomato ( Solanum lycopersicum ) and green and red pepper crops ( Capsicum annuum ), but the profitability of this weed control tactic has not been assessed. Our objective was to determine the profitability of abrasive weeding using empirical yield data from three previously published studies, a range of crop prices and revenues, and a range of costs for wages, grit applicator ownership, tractor use, abrasive grits, and fuel. Results suggest that abrasive weeding was not profitable in organic maize production, and may reduce net income by US$223–3537 ha −1 compared with inter-row cultivation alone for weed control. The cost of abrasive weeding in maize was largely dependent on the cost of abrasive grits and the cost to own a four-row grit applicator (US$736–2105 yr −1 ). However, abrasive weeding was less expensive than hand weeding, especially as the scale of production increased. Abrasive weeding was profitable in tomato and pepper crops and increased net mean income by US$12,251–33,265 ha −1 . However, abrasive weeding was not 100% effective and hand weeding for weed-free conditions was always the most profitable approach to in-row weed management in vegetable crops. The profit potential of the hand-weeded, weed-free treatments demonstrates the importance of weed control in high-value specialty crops–even those grown in plastic mulch film. Despite the profit potential for hand weeding observed here, labor is increasingly difficult to source, retain and afford, and abrasive weeding offers a mechanical alternative with 66% less labor required. Further research is needed to improve the efficacy of abrasive weeding and to reduce the cost of abrasive grits and application.