Companion planting. I do it in my garden. It’s a good way to pack things in. Not sure how it would be accomplished with mechanized farming. There’s also no-till methods which help build healthy soil instead of letting it erode. Keeps the soil biology alive which in turn feeds the plants. Reduced fertilizer and water burden. There are a lot of various farming/gardening methods outside of the mainstream that work as well or better than buying fertilizer and pesticides and spraying it on everything.