What we are learning now is that the presence of green growing plants is even more important to building a living soil than the presence of decomposing organic matter. By planting a mixed perennial meadow under our fruit trees instead of constantly disturbing the soil with weeding, we are adding much more carbon to our soil over time than we could by simply mulching. While getting rid of the oxalis weeds is great, getting rid of the carbon dioxide that is driving climate change is much more important.