Editor’s Note: This is an excerpt from Acres U.S.A. original book, How to Grow Top Quality Corn, written by Dr. Harold Willis. Copyright 1984, 2009, softcover, 58 pages. BOTW price: $8.00 ($12.00 regularly priced.)
By Dr. Harold Willis
So you want to grow top quality corn. Where do you begin?
Soil. The very most basic thing for growing really good crops is good soil. Soil that is not only high in fertility, but is alive with beneficial organisms. The ideal soil for growing corn is deep (six or more feet), medium-textured and loose, well-drained, high in water-holding capacity and organic matter, and able to supply all the nutrients the plant needs. Of course, not everyone has the perfect soil, and corn isn’t so fussy that it can’t do well on less than ideal soil. But I will show you how to build up your soil so that you can grow much better corn.
Climate. Corn does best with warm, sunny growing weather (75–86° F), well-distributed intermittent moderate rains, or irrigation (15 or more inches during the growing season), and 130 or more frost-free days. The U.S. corn belt has these soil and climatic conditions.
Humus. Even if the weather isn’t ideal, a good, living soil with high humus content will often make the difference between a good crop and disaster, for humus allows soil to soak up considerable moisture and hold it for dry periods. It is often the case that one farmer who has been building up his soil will have lush, green crops in a drought year, while his neighbor’s crops have burned up.
Soil parts. An average, good soil should contain nearly one-half mineral particles, one-fourth water, one-fourth air, and a few percent organic matter. The minerals supply and hold some nutrients and give bulk to the soil. Water is necessary for plant growth and for the soil organisms, but not too much or too little. Air (oxygen) is needed by roots and beneficial soil organisms. Organic matter (humus and the living organisms that produce it) is a storehouse of certain nutrients, holds water, gives soil a loose crumbly texture, reduces erosion, buffers and detoxifies soil, and even helps protect plants from diseases and pests because of antibiotics and inhibitors produced by beneficial bacteria and fungi. Some of these friendly microbes also produce plant growth stimulators, others help feed nutrients directly to roots, and others trap (fix) nitrogen from the air—free fertilizer.
But things can go wrong. If the soil is short of air from waterlogging, low humus, compaction, or crusting, roots will suffocate or be “stunned,” and the “bad guys,” anaerobic bacteria, will take over and release nitrogen (denitrification) and produce several toxic substances, such as hydrogen sulfide, ammonia, aldehydes, and alcohols, when they decompose organic matter. Tight and wet soils are one of today’s worst enemies of good quality crops.
Nutrients. To be healthy and produce excellent crops, a growing plant needs an adequate and balanced supply of over a dozen nutrients, mostly coming from the soil. Some are needed in larger amounts (the major nutrients: nitrogen, phosphorus, potassium, calcium), while others are needed in smaller amounts (the secondary and trace elements: magnesium, sulfur, iron, copper, zinc, manganese, boron, molybdenum, and chlorine). These plus carbon, hydrogen, and oxygen from the air and water are put together by the plant to form carbohydrates (sugars, starches, cellulose), fats, proteins, vitamins, and other miscellaneous products. Photosynthesis (powered by the sun’s energy) and other metabolic processes accomplish these feats.
In a living, well aerated, fertile soil, the minerals, humus, and microorganisms should supply all of the plant’s needs if there are no stresses from weather. But things often don’t work out ideally, plus with the high populations of corn that are grown these days, some supplementation with outside fertilizers is usually necessary. Fertilizers will be covered in the next chapter.
Seedbed preparation. There are several basic methods and many variations of ways to till the soil and prepare a good seedbed for planting. An ideal seedbed is warm, moist, well aerated but firm soil. Old timers used to carefully plow and harrow the entire field to uniform fineness, but since only the row serves as the seedbed, some methods only prepare a seedbed in the row, leaving the soil between the rows rougher. This will provide a poor seedbed for weeds between the rows and allow the corn to get a head start.
Dr. Harold Willis has a wide background in biology. Born and reared in Kansas, he earned B.A. and Ph.D. degrees in biology and entomology. He taught at the university level for 15 years before entering the areas of agricultural consulting and writing. His other books include Foundations of Natural Farming, The Coming Revolution in Agriculture, The Rest of the Story . . . about Agriculture Today, How to Grow Super Soybeans and How to Grow Great Alfalfa & Other Forages.