Dig the soil with a shovel to a depth of 8 inches to loosen it and improve drainage. Add compost, grass clippings or spaghnum peat moss if the soil is very sandy or very heavy. Rake the soil to level it.
Dig holes in the soil 6 inches deep and spaced 6 inches apart. Place one fish in each hole. If the fish are larger than 6 inches, cut them in half. Smaller fish decompose more quickly and fertilize corn more efficiently.
Cover the fish with soil. Plant corn seeds 1 inch deep and space the seeds 12 inches apart. Corn is wind pollinated and grows best when planted in blocks or on hills. Plant at least four rows of corn, spaced 12 to 18 inches apart.
Water the soil to keep corn evenly moist throughout the season. Side-dress the corn with manure or synthetic fertilizer when the corn stands knee high, and again when it begins to produce ears.