GMOs result in less tillage (which removes nutrients from the soil and causes erosion) to address weeds since the crops are herbicide-resistant.
GMOs are also good for the environment because they use fewer pesticides and waste less water. Modifying crops to be pest-resistant means that there is less need to use pesticides. These pesticides are harmful to the environment and to animals such as honeybees and monarch butterflies.
Crops can also be modified to be drought resistant which would help to waste less water.