Answer: Your corn needs more nitrogen, says Dale Wilson, professor of horticulture and sweet corn seed expert at the Southwest Idaho Research and Extension Center in Parma. When nitrogen levels are deficient, the corn takes nitrogen from its oldest leaves and sends it to the top portion of the stalk, where it's needed most. Nitrogen deficiency is a particular problem on the sandy soils in your area, adds Wilson. To insure adequate levels to grow corn, add 50 to 60 pounds of composted manure per 100 square feet of corn patch in the early spring. Side dress the corn at the five leaf stage with 1 1/2 pounds of ammonium sulfate per 100 foot row, lightly working it into the soil one foot from the plants. If you still see symptoms, try a second side dressing at tasseling stage. Since soluble fertilizers such as ammonium sulfate can leach out quickly in sandy soils, amendments high in organic matter, like composted manure, are better to use because they release nitrogen slowly. If you want to use an organic fertilizer for side dressing, try cottonseed meal at rate of five pounds per 100 foot row. For very quick results in a small plot, use fish emulsion or manure tea. A regular application of fresh manures or large amounts of compost, leaves or green manures will build up the levels of organic matter in your soil, and nitrogen won't be lost so rapidly.
Q&A Library Searching Tips