Farmers used to rely on tilling the soil to remove weeds from their fields. It dried out the soil, leading to erosion and reduced fertility. Biotech crops like Canadian canola are tolerant to herbicides. By spraying herbicides on their fields, farmers can control weeds while protecting their crops and soil. They no longer need to till their fields every year, keeping our soil moist and fertile.
Source: Smyth et al. (2011). Environmental impacts from herbicide tolerant canola production in Western Canada. Agricultural Systems, 104 (5), 403–410.