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Here's one way to help corn, soybean emergence

Planters are still running in corn and soybean country, but the frustratingly long spring planting season is at or near its end for many farmers.

Though isolated showers could mean delays in spots through Memorial Day, it's the seed that's already in the ground that could pose the bigger long-term threat to yields when the '08 crops are in the bin. Some farmers already are pegging a yield loss this year of between seven and 10% below trend.

Slow emergence like this has been noted around the Midwest. Now, ironically, the main culprit of slow planting progress earlier in the spring may be needed to get emergence on track, according to Iowa State University Extension field agronomist Virgil Schmitt. In his area in eastern Iowa, rains now will benefit the corn that's already in the ground, especially those acres planted under less-than-ideal conditions.

"It is hard to believe, given how wet it has been this spring, but we could use a nice rain to soften the crust on many fields where crops have not yet emerged," Schmitt says. "Corn seldom needs help with emergence, but I have been in some fields where the crust is very thick and hard and enough light is getting down through cracks in the soil that the coleoptile (tip of the shoot) is turning green. The green color means that photosynthesis is being conducted and the plant may 'think' it is at the surface and the leaves may begin to unfurl underground."

You can avoid this problem by tillage with a rotary hoe, Schmitt says. But, it's important to know if and where your corn's germinating and emerging, otherwise you may do more damage than good.

"Rotary hoeing may aid emergence, but it can also cause much damage," he says. "If the tips of the coleoptiles are close to the surface, the rotary hoe may cut many of them off, resulting in significant loss of population. And if some plants are already emerged, some of them may also be lost due to rotary hoeing."

Soybeans may require more help in poking through crusted soils than their row crop cousin, corn. Still, the potential for crop damage is just as much of a factor with rotary hoeing beans, Schmitt says.

"If the seedlings are just below the surface so the arch (neck) is close to the surface, rotary hoeing may break off many of the seedlings, and they will then be lost," he says. "If seedlings are still deeper in the soil, rotary hoeing may be a tremendous help."

So, how can you tell if this tillage will do the trick for your corn and soybean emergence? Schmitt suggests a quick field test, running the implement a few yards in the corner of a field. Gauge the field's readiness by then checking the depth of seedlings in the soil.

"If little damage is being done to the crop, continue to rotary hoe. If damage is severe, leave the field and see if the plants can make it on their own," he says.

Planters are still running in corn and soybean country, but the frustratingly long spring planting season is at or near its end for many farmers.

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