Improving Corn and Soybean Yields

Beck’s Hybrids conducts annually extensive corn and soybean research to improve crop yields. They recently released a 256-page book on their recent results. Research is conducted throughout the USA, Midwest, and Ohio. 

Over 2 decades, the yield penalty for late corn planting is less than on soybeans. The most important thing on corn is getting it planted at a consistent depth, spacing, population, and under the right conditions more so than actual planting date. In no-till, having good closing wheels to close the slot is essential. Optimal seed to soil contact is critical for uniform emergence and the yield benefit was 2.7 to 5%. Spiked wheels help crumble soil when conditions are not perfect. 

Becks did significant corn nitrogen (N) research. Putting N fertilizer on both sides of the seed allowed more uniform root distribution and yielded an average of 7 bushels more corn. The highest average corn yield of 225 bushel per acre over 4 years was 60# N applied on both sides of the seed. Split applications can reduce N losses. There appears to be no advantage to applying N early and even less by applying N the previous fall. The highest yield came from applying N side-dress next to both sides of the seed and growing plant at V3 (three true corn leaves). 

If conditions are right, planting early can be beneficial as long as seeding depth, spacing, and good seed to soil contact occurs. Early planting allows the plant to capture more sunlight and for more carbohydrates to be produced for potentially higher crop yields during grain fill. On cold wet soils, especially in no-till and strip till soils, a little extra phosphorus (P) fertilizer is helpful for increasing crop yields. Cold wet conditions and low P soil test soils respond to P fertilizer in the furrow or in a 2” to the side and 2” deep (2 X 2) placement, yielding 1.2 to 9.5 bushel more corn. On sugar applications, the yield response is the highest and the most beneficial when sugar is applied to warm soils. When planting late or in warm soils, sugar provides some extra carbon for the plant to fully utilize N to make amino acids and proteins. 

On biologicals and bio-stimulants, Becks’ research found that some are helpful, especially when some organisms or biology is deficient. Some worked better when applied in furrow with the seed, others better in a 2 X 2 placement. The yield advantage ranged from 3.3 to 9.8 bushel of corn/acre on six products. 

A big problem occurs with residue management and that starts at harvest. Uneven distribution of corn residue or soybean residue causes difficulty next spring in warming up the soil and drying it out for proper planting. Even residue distribution is critical to getting good corn and soybean stands. Ideally, 80% of the residue should be decomposed at planting time which helps to warm the soil but also to release nutrients to the next crop. With the increased use of some insecticides and late harvesting, some biological organisms (springtails, mites, earthworms, etc) may be reduced and the colder temperatures reduce the time for decomposition. Some equipment modifications (crop residue devastators, chopping heads) have been shown to help increase crop yields up to 15 bushel per acre. On soybeans, getting a good stand is critical but too many soybeans may cause competition between the soybeans and weaker plants. In Ohio, drill soybeans are common but in many parts of the Midwest, 15-inch and 30-inch row soybeans perform just as well or better. Becks found that soybean yields start to decline after the final soybean stand was greater than 175,000 per acre. 

On soybeans, foliar nutrient applications were found to be beneficial starting at V3-V4 (vegetative growing stage) and again at R1-R3 (reproductive stages when soybeans are blooming and setting pods). Yield bumps of 1 to 5 bushel were noted. Manganese (Mn) foliar applications applied during the early vegetative stage had the greatest return. Manganese is needed to split the water molecule to form proteins. Avoid applying Mn with glyphosate (Roundup) and always apply with a fulvic acid to increase Mn plant uptake. 

Later in the season at R1-R3, Boron (B) is important for increasing nodules, assisting in pollination, and increasing pod fill. Boron and calcium are very closely tied together. Calcium needs B to be absorbed in the plant. Calcium and B work together and have similar crop responses, so both need to be adequate for the best growth and crop yields. Beck’s research found that multiple foliar applications of B increased soybean yields due to longer pod fill. After a wet weekend, hopefully the planting season gets started again!