Weeds are an index of what is wrong, and sometimes what is right, with the soil. Or at least with the fertility program.
In every field on every farm there are different soil types and each has a potential for producing certain weeds. In high rainfall areas where farmers depend on rain for irrigation, broadleaf weeds proliferate. These include lamb’s quarters, pigweed, Jimson weed and buttonweed. This is an indication that soil conditions are good and fertility is excellent. Where soil structure is poor and farmers work the soil under wet conditions, they usually build compaction, which sets the stage for grassy weeds. Incidence of foxtail and fall panicum sends a signal of an imbalanced pH and a degenerated soil structure.
Correct soil management requires pH adjustment along with well-digested compost, efficient use of water and soil aeration. When this is done there is no need to add chemicals! Weeds rarely get a toehold in a well managed field, even when herbicides are not used. Weeds have a pecking order. Once the conditions that permit foxtail and fall panicum, for instance, are erased, there will be other weeds, but they will have a different message. Lambsquarters and pigweed send the message that the crop will thrive and insects will stay away. Cocklebur indicates that the soil’s phosphate level is good. And even dandelion is a friendly weed. It’s roots penetrate some three feet into the soil, transporting calcium and other minerals to the surface. Earthworms like dandelion because each time the plant dies the root channels become a conduit for worm travel and a colloidal source of worm nutrition.
Weeds deposit nutrients into the soil, but where do these weeds get their nutrients? Eighty percent of plant nutrition is from the air! Most of this nutrition is taken from carbon dioxide and water, but it also includes cosmic and solar energy and airborne nutrients. The effectiveness of this direction of nutrient flow is totally dependent upon two conditions: the inherent integrity of the plant and/or seed and the health of the soil.
Weeds are weeds only in our eyes. Ehrenfried Pfieffer said, “Weeds are specialists. They survive under circumstances where our cultivated plants cannot stand up against nature’s caprices. Weeds resist conditions, such as drought, acidity of soil, lack of humus and mineral deficiencies. They are witness to man’s failure to master the soil. They indicate our errors and nature’s corrections.”