By: James Hoorman
Everyone likes to follow a winner! Top farmers develop a suite of management practices that allows them to achieve higher average yields than their neighbors. High crop yields usually come from doing several things right and usually the weather has to cooperate.
The world record holder on corn, David Hula, recently shared several of his high yielding management practices. Hula holds the all-time world corn yield record of 616 bushels set in 2019, on an irrigated strip till farm in Charles City, Virginia. Strip-till is a system where a 6-inch ban is tilled (fall or spring) before corn is planted. About 80% (24 inches in a 30-inch row) is left as no-till. The six-inch ban warms up quickly in the spring and allows corn to get a quick start. Cover crops can be planted between the tilled strips to add carbon and to improve soil health.
Hula says getting corn off to a good start is a major key to high corn yields. The strip till section is usually a little drier and in a wet spring, much warmer. Soils are cold because the soil water holds in the cold until it is replaced by air. That small tillage zone allows corn to germinate faster and get off to a fast start. The other no-tilled soil has better soil structure, so excess water can infiltrate, drains better, but also holds more water for summer plant growth. The corn roots can grow into the no-till zone, gathering both water and soil nutrients.
Hula says the next important thing after a good start corn is having good nutrition, fertilizer, and micronutrients, which is a major key to higher crop yields. Keeping nutrients in balance allow the plant to defend itself from insects and diseases. High plant nutrition allows plants to grow quickly and canopy, minimizing weed competition. Farmers should concentrate on avoiding practices that negatively effect plant growth. Strip tilling in wet soils cause soil compaction which has a huge negative impact on root and plant growth. Image vertical tilling an entire field when its wet, resulting in high soil compaction. Crop roots become restricted, growth slows down, and yields quickly follow the same path. Crops with good root systems have the best opportunity to optimize yield.
The no-till area, if planted to cover crops, is high in biological activity and high in carbon. The carbon comes from decaying roots and helps optimize yield. The higher microbial activity increases soil fertility and maximizes the release of micro nutrients.
Hula is experimenting with adding sugars, using Smart KB, a foliar liquid potassium (K) product, adding boron, and using biologicals. Adding sugars to nitrogen fertilizer may improve nitrogen use efficiency, becoming the carbon to make proteins. Potassium (K) improves nitrogen use efficiency and mitigates some crop stress. K is often tied up in the soil minerology or in poorly structured compacted soils. Increasingly, low boron is becoming a problem. Boron is the way plants move calcium into the plant. Adequate calcium is needed for many plant functions including seed germination; root, shoot, and leaf growth; increases pollination and flowers; and improves grain quality. There are many beneficial biologicals including mycorrhizae fungi (MF), bacteria, and other microbes which improve plant nutrition and soil health.
To maximize the benefits of this system, farmers also have to maximize crop maturity. Generally, if early to mid-season crops are planted early, the crops will be harvested earlier. Quick growing corn and soybeans varieties may pollinate earlier before hot temperatures and moisture stress starts limiting yield. Early harvested crops can yield as well or better than late planted crops. Early harvested crops generally have less grain moisture, may generate a crop premium, and allow timely planting of another crop (wheat, cover crops).
Weather can be a major issue. In Ohio, cold wet springs are normal. Combining a 6-inch strip till system with 24-inches of no-till and cover crops allows farmers to benefit from both systems. The no-till area with cover crops increases soil structural stability so that crops can be planted earlier. This area also has higher microbial activity for good plant nutrition and root growth, plus more water. The stripped tilled area gets the corn off to a quick start, while the no-till/cover crop area sustains the crop during hot summer months when moisture may be limited. The cooler temperatures in the no-till/cover cropped area allows microbes to flourish and feed the growing crop. The extra carbon from cover crop roots plus the release of nutrients from the microbes allows both corn and soybean yield to flourish.