Tag Archives: agronomy

Ways to Reduce Soil Compaction

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After unseasonably wet, cold weather this spring, farmers are eager to get their seed in the ground. We understand their sense of urgency, but we also know they’ll have better results if they wait for more suitable field conditions.

The best rule of thumb is to let the field dry before doing fieldwork. Use a quick field test to check the soil moisture: mold a length of soil between your index finger and thumb, or roll it into a ball in your hand. Observe whether the soil breaks apart as you work it. If you toss the ball of soil into the air and it shatters or cracks upon falling to the ground, then conditions are likely suitable for tillage or planting.

Working soils that are too wet this spring could have negative impacts on your crops during the growing season including: stunted plant growth; slow infiltration of water and/or ponding; high surface runoff and soil erosion under normal or light rainfall; poor root system establishment; and nutrient deficiency.

To reduce or minimize soil compaction, consider taking the following steps:

  • Avoid working wet soil. Soil is most susceptible to compaction when it’s saturated and cannot absorb any more water. Use the quick field test method above to access the soil conditions, and begin planting or working the soil only if the proper conditions exist.
  • Reduce tillage. Crop residue can intercept raindrops and prevent the soil surface from sealing and compacting.
  • Use the right implements. The degree of compaction is determined by the moisture content of the soil, as well as the weight of the equipment in the field. Reduce the weight on each axle, choose wider tires and adjust air pressure to reduce the load on the soil surface. Iowa State University research shows that using equipment with 6 pounds per square inch (psi) of surface pressure yielded 9 bushels per acre more than equipment with 16 psi.

Soil compaction can be avoided with better management. For more information, click here to download Iowa State University Extension’s publication, Understanding & Managing Soil Compaction.

2011 Corn Crop Isn’t Necessarily Behind

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There has been much talk recently about the wet, cold planting conditions throughout the country. On Saturday, a TV reporter said that only 2% of Iowa’s corn crop was planted as compared to the 16% that had been planted by the same time last year.

The percentage of corn in the ground by April 22 doesn’t mean the 2011 corn crop won’t be another bin-buster. Keep in mind that last spring’s soil and weather conditions allowed farmers to plant more acres much earlier than the norm. On average, only about 7% of Iowa’s corn acres has been planted at this time of year.

It’s easy to compare present conditions to just one year ago, so let’s take a minute to reflect on what happened in 2008. Spring rains in Iowa that year resulted in saturated soils, cool soil temperatures and soil conditions that were less than ideal for planting. Iowa State University Extension Corn Specialist Roger Elmore said, “Many farmers were guilty of ‘mudding in’ some corn that year. The penalty: reduced yields.” Click here to read Iowa State’s Integrated Crop Management NEWS from May 2008.

It’s documented: Reduced yields result from planting under conditions that are too wet and too cold. Keep this in mind the next time someone says, “It pays to plant early.” And then chides you because your planter isn’t yet rolling.

“Regardless of calendar date, producers should wait for suitable seedbed conditions and the short-term forecast calls for pleasant weather,” advises Elmore.

Remember that although you may not have your corn planted as early as last year, it’s still “early.” There are literally weeks of optimal planting dates left, and on average, farmers need only one week or less to get all of their corn acres planted.

You can afford to take the extra time to wait for seedbed conditions to improve. In fact, exercising patience now will mostly likely pay dividends this fall. When conditions are far less than ideal, it pays more to wait!

Applying Recommended Nitrogen to Corn Maximizes Returns

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Applying nitrogen to corn at recommended rates is critical to maximize economic returns, minimize environmental losses and conserve energy, says John Sawyer, ISU Extension soil fertility specialist and agronomy professor.

In an effort to increase awareness of farm energy conservation practices, Iowa State University Extension has released a publication titled, Energy Conservation in Corn Nitrogen Fertilization. This publication shows the energy consumed during the production of nitrogen versus phosphorus and potassium fertilizers. It also provides resources to determine recommended nitrogen application rates for corn, such as the online Corn Nitrogen Rate Calculator from ISU’s Department of Agronomy.

More information, including a link to this Extension publication, is available today from Wallaces Farmer online. To view the entire article, click here.