From the Field™ Crop Report in Southwest Iowa: May 1, 2013

Soil temperatures are ranging from the mid- to high 50s, so we’ve seen a lot of action during the past 5 days. Alfalfa seeding is wrapping up with perfect conditions. Thankfully, very few fields damaged from the open winter.

Planters are going hard, and corn planting is 10 to 15% complete in western Iowa. However, there’s very little field action in eastern Nebraska with less than 5% of the corn acres planted.

Fields Not Yet Fit for Planting

With temperatures hovering around freezing and more snow flurries in the forecast, the only place planters are “rolling” now is down the road.

Daytime highs during the month of April haven’t been much warmer than the average lows for this time of year. As a result, soil temperatures haven’t warmed much during the last week. Plus, many fields are too wet to work after nearly a weeks’ worth of rains.

As eager as everyone is to get corn planted early, we need to let soil temperatures and soil conditions – not the calendar – dictate planting dates. Early planting dates lead to higher yield only when conditions are fit for planting.

Optimal planting conditions include warm, moist soils. Right now our soils are cold and wet. We recommend soil temperatures of 50 to 55 degrees at corn planting time. But current 4-inch soil temperatures in Northwest Iowa are only averaging 39 degrees; they’re averaging 42 degrees in North Central Iowa.

Soil temperature isn’t the only factor delaying the planting this spring. Iowa experienced its wettest week since July 2010 with a statewide average of 2.90 inches of rain, according to the April 15th crop report by the Iowa Department of Agriculture and Land Stewardship. We need soils to dry before fieldwork can begin, but more rain is in the forecast. The forecast for the area surrounding Latham headquarters calls for a 100 percent chance of thunderstorms today with total rainfall of one inch. There’s a 60 percent chance for another quarter to a half inch of rain tomorrow with snow in the forecast for Friday.

From the sounds of it, field work isn’t likely to begin anytime soon. Be sure to wait for “fit conditions” before getting your planter out of the shed. To avoid working soils that aren’t fit, there are 3 things for Midwest farmers to consider:

  1. Be sure soil temperatures are at least 50 degrees before planting corn.
  2. Check the moderately long-range and long range weather forecast to ensure ambient air temperatures won’t freeze seedlings.
  3. Reduce or minimize soil compaction by:
    1. Avoiding wet soils,
    2. Reducing tillage, and
    3. Using the right implements.

Working soils that are too wet leads to yield loss and more problems during the growing season from soil compaction. Restricted root development, nutrient deficiency and reduced infiltration rate are among the top 10 reasons to avoid soil compaction. For ways to reduce soil compaction, click here.

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Crop Report: April 18, 2012

The past week brought driving rain, hail, frost and even some snow across Latham Country. Colder ambient air temperatures have led to colder soil temperatures, which are now below 50 degrees in many counties across the Upper Midwest.

A sustained soil temperature of 50+ degrees is needed for corn to germinate. Chilling injury can affect the corn plant very early during germination (just 1 to 2 days after planting) and cause stunting or total death of the root system so that the plant fails to emerge, says Latham’s agronomist Mark Grundmeier. Chilling can also take place after germination but before the V4 stage if soils temps drop into the low 40s.

With cold soil temperatures and the threat of chilling injury, there’s no need to rush into the fields. It’s only April 18, after all. Many prime planting days remain. Research by Iowa State University and the University of Nebraska – Lincoln shows that corn planting dates range from April 11 to May 13 for 100% yield potential. The last 5 days of April and the 1st week of May result in the highest yield potential for soybeans.