From the standpoint of economics it befuddles me why growers would not desire to give their corn crop the best opportunity to come out of the ground like a roaring lion.
With the potential of $5.50-plus for December corn, giving corn seedlings a chance at developing a large root system, and kicking the photosynthetic factory into gear at high speed in a soil environment that is ready, makes sense.
In reality, it doesn’t take much to have nutrients very close to the seedling root and jump-start this factory into action.
But a word of caution is in order for starter: We need to use the best-quality fertilizer material with as low of a salt index as possible. The old standby of 10-34-0 is not a bad product. However, its salt index is one of the highest on the market. Tender corn-root tissues near this material could be a problem at rates above 5 to 8 gallons per acre and could damage the seedling roots.
We encourage corn growers to consider a starter program, especially with strip-till. The previous crop residue in a field of corn-on-corn will have big demands to balance the carbon-to-nitrogen (C:N) ratio in the top 6 to 8 inches of the soil. Because corn residue has a C:N ratio of 50:1 — compared to wheat stubble at near 80:1 — it’s important that the ratio is near 20:1. By keeping the ratio near 20:1, microbial action can release organic forms of nitrogen.
Having some nitrogen available, and in the right form for the ‘baby’ corn plant to use — so the nitrogen doesn’t have to compete with all of the microbes working to breakdown residues loaded with carbon — has incredible merit. It helps keep the plant from essentially starving.
Strip-tilling puts corn plants in an environment with a great root zone. The corn plants are in a non-compacted soil medium. The soils are warmed up and the plants are ready to take on moisture in the presence of strategically placed nutrients.
And, just as importantly, the soil tilth has low-enough soil density so that it doesn’t impede sound, deep root penetration.
But all of this requires some nitrogen that the small photosynthetic ‘factory’ in the young corn can roll ahead. The answer for this situation is starter fertilizer.
For centuries, farmers have tilled soils to reduce soil density so it’s less than 1.25-1.30g/cm3, if possible. A corn plant at V2 to V3 may exert 80 to 120 psi of force, at the most, to push roots downward. The corn plant can exert more force than that, but that takes energy and food. That’s why corn plants need nitrogen, phosphorus, potassium and micronutrients to generate the power.
With strip-till, wev’e observed and measured seedling root extension that is 160% to 300% more than in no-till, even with nutrients placed right with the seed in both systems.
Compared to conventional full-width tillage, strip-till still outperforms with roots extending 120% to 240% longer roots in the clay-loam soils at the Orthman Research Farm in Lexington, Neb.