No-Till Wheat a Risky Bet

If there was ever a year to settle the argument of no-till versus minimum-till on the semi-arid High Plains, 2010 is the year.

Planting conditions this fall have been the worst in recent memory, thanks to the hot and dry conditions brought on by La Nina. Every month since May has had below normal precipitation in our region.

Temperatures, meanwhile, have been so unseasonably warm, October has often seemed like we were in the middle of July. We've even hit record highs with triple-digit heat on the most extreme days. With that kind of heat combined with drought stress, 2010 is going down as the year from hell.

In such extreme dry years, which is the best method for planting next year's wheat crop?

No-tillers argue their way is the preferred method of field operation because field residue, they believe, saves moisture and shades the soil.

These are side-by-side fields. The left is ungerminated seed in a no-till field. The right is a stand of wheat in a minimum tilled field. Both fields were planted at virtually the same time.

Farmers who practice minimum tillage, meanwhile, say they are able to plant deeper with a hoe drill to where the soil moisture is in dry years, allowing for more immediate germination of the seed and establishment of a stand before winter.

But in dry years like this when we are at such severe moisture deficits, does either practice make a difference?

Plant Emergence According to Jim Shroyer, Kansas State University extension agronomist, neither method is going to do extremely well under these conditions. Both methods, he adds, also present their own set of problems.

In a no-till system, the soil can be so hard the seed cannot be planted deep enough to reach moisture, therefore delaying germination. Planting at a shallow depth in no-till if the soil is too hard brings additional risk of winterkill with the crown of the seedling being close to the soil surface and vulnerable to freezing temperatures.

Meanwhile, in a minimum-till system, the ground can be worked enough that the moisture leaves the soil over time, leaving nothing to support germination or later growth.

The bigger issue, Shroyer advises, is when the wheat is going to come up. Late-emerged wheat results in fewer tillers, which could lower yields.

Using a higher seeding rate if you're dusting it in is the preferred method, he says. As for no-till versus minimum-till, the difference between the two is most obvious in two side-by-side fields in our area. In the no-till field, the seed was planted directly into shallow dry dirt and milo stubble. Most of the field still has not germinated.

Across the road is a field farmed under minimum tillage and planted at virtually the same time. The minimum-till field has already produced a stand. While it may not be an impeccable stand, the wheat is still up.

The emergence - or lack there-of - makes all the difference. If a rain ever develops this fall, the no-till field will just be getting started while the minimum-till field will already be adding tillers.

And if the worst-case scenario unfolds and a rain never materializes this fall, the stand of wheat on the minimum-till field still is going to prevent the ground from blowing this winter. The bare soil in the no-till field won't be as lucky with the milo stubble having virtually disappeared due to months of high winds and no rain.

While a good, soaking rain is the only way to cure a drought, the story on what to expect at harvest when it's bone dry at planting is already being written: Minimum till so far is going to be the likely winner.