When it comes to conserving soil moisture, no-till residue can go a long way. In times of drought, residue cover can be an added line of defense against the parching sun, but it is no cinch to get seed in the ground with a residue cover in place. Too much residue disturbance, and most of the moisturizing benefits of no-till may evaporate -- not enough residue disturbance and one risks uneven emergence as the residue can form a canopy over emerging seedlings, eclipsing the sun's rays. The University of Nebraska-Lincoln Extension offers the following tips:
Leave residue over the row -- The crop residue left over from the season will help keep the soil underneath cool and hydrated. This helps reduce evaporation and keeps the root zone cooler for the whole season.
Use seeding disks to cut residue -- Correctly aligned, sharp double disk seed furrow openers on planters can usually cut through crop residue to place seeds. Some growers prefer to use coulters, but in some occasions, these can push the residue down without cutting it creating "hair pinning" and making it difficult to get the seed where it needs to go.
Provide uniform residue cover -- Residue movers can be used, but a word of caution -- crop residues are really at maximum effectiveness when left as undisturbed as possible. Uniformity is important, especially if you have a pile of shucks and cobbs lying here or there from some 'on the fly' combine maintenance in the field, but I would be careful with trying to smooth residual plant matter as turning it over can sacrifice all the hydrating benefits crop residue has to offer.
Add downpressure springs and weight to ensure penetration -- If enough downpressure is not exerted on your iron to engage the depth gauging wheels, add some weight. If soils are already dry and hard, add to it a stalky crop residue to bust through as well and you might need a little extra something to make sure seeds achieve proper depth.
Plant on or near the old row -- The most biologically active area of any field is the root zone from the year before. Rows roughly five inches to the side of the old row work well as they lend access to the prior crop's root zone while minimizing planter bounce and tire wear.
Planting deeper may be warranted in dry years -- If your soil is dry, consider adjusting your planting depth to somewhere near the maximum depth recommended for your specific planter. This will improve uniformity, and create a better environment for germination.
Ensure good seed-vee closure -- This will provide good seed-to-soil contact and keep the seed zone from drying out. Some growers use spoked closing wheels, while others have reported good success using one spoked and one regular closing wheel. If you aggressively spoke as you go, consider a drag to smooth the soil behind you.
Growing in dry soils can be a challenge. But with a decent residue cover and a little forethought, drought year planting in a no-till field can pack some real advantages. For more on this from U of Nebraska-Lincoln Extension click here.
Photo credit: Elcajonfarms / Foter.com / CC BY