Weed Management on Organic Farms
Organic farmers struggling to develop effective and economical weed management practices are not alone. Farmers rank weeds as the number one barrier to organic production (Walz, 1999). And organic farmers cite weed management as their number one research priority. In approaching weed management within an organic system, it is important to remember the central goal: to reduce weed competition and reproduction to a level that the farmer can accept. In many cases, this will not completely eliminate all weeds. Weed management should, however, reduce competition from current and future weeds by preventing the production of weed seeds and perennial propagules — the parts of a plant that can produce a new plant. Consistent weed management can reduce the costs of weed control and contribute to an economical crop production system. This chapter describes weed control strategies for organic farms based on weed characteristics and an integrated cropping system approach:
- What is a weed? Weedy plants share common characteristics that must be considered.
- Preventing weeds. Crop rotations, ,cover crops, stale seedbed preparation, soil solarization, proper sanitation, and composting can prevent weeds from emerging and spreading.
- Increasing crop competitiveness. Choosing the right cultivar, using transplants, seeding correctly, ensuring crop health, and applying mulches can give crops a competitive advantage.
- Special topic: Cultivation practices for organic crops. Using the right cultivation tools at critical times can contribute to a cropping system that limits both emerged and future weeds.
- Additional tools for weed management. Animals and approved herbicides can supplement cultural practices for weed control on organic farms.
- What researchers are doing. High-tech weed control, natural weed control, crop breeding, and cropping systems are key weed research areas.
- Advantages of organic production. Organic practices can create conditions that naturally limit weeds.