Does it make a difference to use a starter fertilizer product in corn?

From the standpoint of economics this question befuddles me as an agronomist why any grower would not desire to give his/her corn crop the best opportunity to come out of the ground like a roaring lion.  With a year [2012] of looking at plus $5.50 potentially for December price, giving the seedling a chance at developing a large root system, and kicking into gear the photosynthetic factory at high speed in a soil environment that is ready surely makes sense.  In reality it does not take much to have nutrients very close to the seedling root and jump start this factory into action.  It is with a bit of caution though with starters that we use the best quality fertilizer material with as low of a salt index as what you can get.  The ole standby 10-34-0 is not a bad product, we have found many times over better products to use, however with its salt index as one of the highest on the market, and the tender corn root tissues – near this material could be problematic at rates above 5-8gpa (from my experiences) and cause seedling root damage.

We at the Orthman Research Farm encourage when considering a starter program especially with a Strip-Tillage program.  The remaining previous crop residue (corn on corn) will have big demands to balance the C:N ratio in the soil surface 6 to 8 inches.  When corn residue has a C:N ratio of 50:1 compared to wheat stubble at near 80:1, it is still important that for microbial action to release organic forms of N the ratio needs to be more near 20:1.  Having some nitrogen available and in the right form for the “baby” corn plant to utilize it and not have to compete with all of the microbes working to breakdown residues loaded with carbon has incredible merit to keep the plant from essentially starving.  We have put the corn plant in an environment with a great root zone with strip-till, a non-compacted soil medium, warmed up soils, ready to take on moisture, strategically placed nutrients, and soil tilth that has low enough soil density to not impede sound deep root penetration.  But all of this requires some N for that small photosysnthetic factory to roll ahead. Solution = starter fertilizer!

It is why growers have tilled soils for centuries, to reduce soil density to be below 1.25-1.30g/cm3 if possible when the root exertion of the baby corn plant is something like a child under three years of age.  A small V2-V3 plant exerts maybe 80-120psi of force at the most to push downward.  Can the corn plant exert more force than that? Yes but that takes energy/food — thus the need for N-P-K and micronutrients to have the power.  With strip-tillage such as the Orthman 1tRIPr completes, we have observed and measured 1.6 to 3X the seedling root extension length compared to No-Till even with nutrients placed right with the seed in both systems.  Compared to conventional full width tillage methods the strip-till still outperforms with roots extending 1.2 to 2.4X the root length in the soils at the Orthman Research Farm that are clay loam in texture.  We will say over and over again, “it is much to do about roots with strip-till”!

By: Mike Petersen, Lead Agronomist for Orthman Mfg.

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