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High Residue Farming under Irrigation Publications

Posted December 17, 2014

EM071 High Residue Farming Under Irrigation: What and Why provides an overview of high residue farming (HRF), including its benefits and challenges. It also discusses some special considerations for high residue farming in the irrigated agriculture regions of the far western United States.

EM072 High Residue Farming Under Irrigation: Crop Rotation covers choosing a cropping sequence, specific cover crops, and special considerations for irrigated cropping systems in the far western United States.

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Crop Residue Saves Water

Posted May 12, 2014

Besides protecting the soil surface, crop residue can reduce evaporation, saving water for use by your crops.

Evaporation from soil occurs in three stages:

Evap stages

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Soil Organic Matter Boosts Water Holding Capacity

Posted May 7, 2014

The amount of water in the soil that is available to crops is another soil property that can be improved by increasing organic matter content. B. D. Hudson, in a 1994 paper, presented data on this for sands from Florida and silt loams from Iowa, Kansas, Minnesota, and Wisconsin (Hudson, 1994, as redrawn in Franzluebbers, 2010): Read more »

Protect the Soil Surface to Increase Water Infiltration

Posted April 28, 2014

If you want your soil to take water faster, protect the surface with crop residues. This was shown in a classic study from 1940.

F.L. Duley took a sandy loam, covered it with straw, and then applied a simulated rainfall to it for five hours at a rate higher than what it could take, resulting in runoff. He measured the rate of water entering the soil (infiltration) which settled to a nearly constant 1.2 inches per hour (click on graph below). After 40 minutes of this, he removed the straw. The infiltration rate of the now bare soil dropped rapidly, then leveled off at just 0.25″ per hour.

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Lessons from Cover Crops Overseeded into Corn

Posted April 23, 2014

In a 2013 on-farm trial, we evaluated cover crop species for their ability to germinate and grow when overseeded in late summer into a corn crop. Here are the main conclusions:

  1. There are many cover crop species that will germinate well when overseeded into standing corn in the Columbia Basin. However, most do not do well when shaded more than 2-3 weeks.
  2. Planting 2-3 weeks before harvest may improve plant survival, although crushing by harvest equipment can then become a problem. This is in agreement with Midwest recommendations to plant 2-3 weeks before silage harvest, or for grain harvest, when corn plant is dried to the ear. However, in contrast to the Midwest, we generally field dry grain corn, and so following the latter timing would allow very little growing time for cover crops after grain harvest. This makes overseeding cover crops into corn being harvested for dry grain impractical.
  3. The short growing season after corn harvest, even after earlier harvested high moisture corn, probably rules out using warm season and slower growing species, like legumes, as overseeded cover crops, unless they can overwinter AND are allowed to grow to at least early May the following year.

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Concentrate Organic Matter at Surface to Improve Soils

Posted April 15, 2014

Researchers are finding, in the US and in many other countries, that concentrating soil organic matter in the top 2″ promotes several aspects of soil health including nutrient cycling, resistance to erosion, and water infiltration and storage. They find that maintaining a high proportion of organic matter at the soil surface, relative to deeper layers, is more important than the total level of organic matter in a soil. Read more »

Using Crop Residues to get out of the Dammer Diking – Tillage Cycle

Posted March 25, 2014
Previous corn field disked to smooth over dammer diker holes, then planted. Note bare soil.

Previous corn field disked to smooth over dammer diker holes, then planted. Note bare soil.

Farmers wanting to maintain more crop residue cover on their fields are often prevented from doing so by previous dammer diking. While dammer diking controls runoff under center pivot systems, it also leaves large holes in the field, making it impossible to plant a following crop without tillage. The tillage required to smooth the soil surface for planting also buries most of the previous crop’s residues. The bare soil is then susceptible to surface crusting, poor infiltration, and runoff. To fix this, farmers dammer dike their fields, continuing the dammer-diking – tillage cycle. The way out of this cycle is to maintain a crop residue cover on the soil surface.  Read more »

Consider Surface Banding Your Starter Fertilizer

Posted March 17, 2014

Starter fertilizer is necessary for high corn yields at our Northern latitude, and especially with high residue farming systems. A common way to apply dry starter fertilizers has been the 2×2 method, two inches off the row and two inches below the seed. However, recent research has found that surface banding of liquid fertilizer, 2″ off the row, can be just as effective. Surface banding eliminates the need for an extra set of openers, allows greater residue levels and reduces required planter weight. It also allows greater fertilizer rates than popup methods (with the seed).

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Best Bets for High Residue Farming in the Irrigated Columbia Basin

Posted March 14, 2014

When considering the risk of using high residue farming in the Columbia Basin, there are some crops that are high risk and some that are lower risk.

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Cold Springs Reduce Strip-tilled Corn Yields

Posted March 14, 2014

I have talked to several growers who are concerned about how cold springs have reduced their strip-tilled corn yields when compared to corn with full width clean tillage. While we can hope for average spring temperatures, there are a few other things that should be considered.

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