Profitability of abrasive weeding in organic grain and vegetable crops

Abstract

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.

Abrasive Grit Application in Organic Red Pepper: An Opportunity for Integrating Nitrogen and Weed Management

“…In summary, weed suppression and increased potential for crop N uptake achieved by combining abrasive weeding with polyethylene or bioplastic mulch films resulted in increased sweet red pepper yield. A partial budget analysis of this system in Wortman et al (2018) suggests that this yield increase represents a mean net income gain of $33,265/ha relative to the weedy control in plastic mulch. However, the analysis also indicated that organic farmers could increase net income by an additional $38,458/ha if all weeds were removed from the crop row by hand weeding (i.e., the weed free control).…”

Grit effects on grass weeds and grit-weeding in aronia berry (Aronia melanocarpa)

“…However, this conversion can be successful only if applications of abrasive grits actually control weeds with reasonable efficacies and costs for labor and materials. Although grit-weeding may be economically favorable in some high-value organic horticultural crops (Wortman et al, 2020), our work with aronia berries transplanted into landscape fabric can address only some of these issues. Hazelnut shell grit did control weeds with efficacies and time allotments similar to those of manual weeding (i.e., hand-hoeing), of which the latter would be a form of weed control prevalent on organic farms.…”

Systemic Crop Signaling for Automatic Recognition of Transplanted Lettuce and Tomato under Different Levels of Sunlight for Early Season Weed Control

“…However, labor for handweeding is limited and is progressively becoming more expensive. Although abrasive weeding can reduce labor by 66%, the cost of abrasive grits is very high and the efficiency of this technique is very low as it does not involve automated weed detection [5]. More efficient weed control options are needed for vegetable plants.…”