Managing weeds in organic farming systems: An ecological approach

Weed management is an important challenge in all farming systems, but it is especially difficult in organic production without the use of chemical herbicides. Liebman and Gallandt characterized strategies composed of multiple weed suppression tactics that are individually weak but cumulatively strong, as the use of “many little hammers, " in contrast to the single large hammer that herbicides provide. This chapter describes major components of the weed management tool kit for organic farming. It argues that instead of approaching the development of multitactic weed management strategies as a purely empirical, trial-and-error activity, the choice and deployment of weed management tactics should instead be informed by insights from ecological theory. The chapter discusses weed management tactics widely used in organic farming systems in temperate areas. It also provides information on crop rotation, cover cropping, intercropping, and conservation biological control of weeds.