Weed control is essential for crop productivity. Tillage aims at killing weeds by burying them before sowing, but intensive ploughing makes the soil susceptible to erosion and increases carbon loss to the atmosphere, depleting the organic matter bed which is important for protecting the soil surface. Reduced tillage is only feasible when efficient alternative weed control strategies are available. GM herbicide tolerance is a strong promoter of reduced tillage, as a cost-effective, labour-saving and environmentally friendly strategy. The technology was adopted with an unprecedented rapidity over the last ten years. In soybean, the no-till area has nearly doubled in the US and a 5-fold increase was even recorded in Argentina, with Roundup Ready soybean estimated to account for 95% on the no-till soybean area.(1) Besides soil preservation, no-tillage agriculture saves the fossil fuels burned by the engines needed otherwise, decreasing the economical and environmental costs of intensive farming.