When talking about crop protection, it helps to first understand what farmers are up against in their fields. Weeds are a constant challenge for farmers. Not only can they steal nutrients, water, and sunlight from crops, but weeds can clog irrigations, harbor insects, and leave weed seed and fragments in harvested crops.
The weeds that farmers deal with can be much more difficult to manage than your typical garden-variety plants. Weeds like black-grass, for example, can increase tenfold each year if left untreated. High populations of black-grass can reduce crop harvests by up to 70%. 
Over its 40 years of use, glyphosate has become an indispensable tool for farmers looking to improve efficiencies, ensure more productive harvests and preserve the environment.
Glyphosate is applied to weeds and unwanted vegetation; it enters the weed through the foliage, is distributed throughout the plant, including through the roots, and kills all sensitive weeds treated with only one application.
As with any herbicide, the farmer chooses the right application timing (e.g., before planting, after harvest) to apply glyphosate. Glyphosate tolerant crops give farmers the flexibility to apply herbicides at the right time and in the right amounts without impacting the health of the crop. If the crop is not glyphosate-tolerant, it will react in the same way as weeds in the field and die. In situations where a glyphosate-tolerant crop is not available, farmers may apply glyphosate during the growing season with precision application techniques like shielded spray or spot treatment to control weeds while avoiding damage to the crop.
After an application, glyphosate binds tightly to soil particles and is no longer able to control weeds. Soil microbes degrade glyphosate, and it does not persist in the environment. Glyphosate has no herbicidal activity once it reaches the soil and thus there is no long-term exposure to plants.