Despite the late start on corn and soybean planting that many farmers are getting this year, it is vital to delay tillage, manure applications, spraying, fertilizing and planting until the optimum time. Be patient. Wait until your soils are ready. It’s not a race, but you can give your crop a head start by getting everything right at the beginning.

That’s the advice of Chris Clark, an agronomist with AgSource Laboratories. AgSource has a soil testing and crop consulting service at Ellsworth in central Iowa.

As snow melts, many soils quickly become saturated and have a weakened structure. Nearly every soil type is prone to compaction and erosion in spring.

“Any areas that are already compacted will drain even slower,” says Clark. “Remember your 2017 harvest conditions, and consider if that may have created problem areas in your fields. Watch those areas this spring. It is much easier to prevent further compaction than it is to fix it.”

As soils become less saturated, the microbial life, bacteria, fungi, cover crop roots and other soil life help to stabilize soil particles and aggregates (clumps) below the surface, reducing compaction and allowing infiltration. But as long as the soil is cold, these microbes and plants are not yet actively growing or using nutrients, so soil nitrate is prone to leaching as the soil drains.  

“While the fieldwork can begin when the fields are dry enough, wait until the soil is 50 degrees F before planting,” Clark says. “Planting too early will delay germination and result in uneven stands. It’s better to give the plants optimum conditions than to rush things and reduce yield potential.”

Check soil moisture in each field
Even if your neighbor is out in the field, you should wait until your soils are ready, Clark says. “Take it field by field. When determining soil moisture levels by hand, pick an area and soil type that is representative of the entire field. Take a handful of soil from the top 6 inches and gently squeeze it into a ball in your hand. If the soil forms a ball that breaks easily with a little pressure, that indicates the soil is ready to work. Your seedbed is ready for planting when the moisture is right and there are stable soil temperatures for four to five days.”

She also recommends you consider using the preplant soil nitrate test (PPNT), the pre-sidedress nitrate test (PSNT) or the late-spring nitrate test (LSNT) after planting corn to check on the status of nitrogen in each field. You may have lost some nitrogen due to the prolonged wet spring. Plan to sidedress-apply any nutrients that may be needed.

“Good soil structure helps to retain plant-available water for longer periods between rains come summertime,” Clark says. “So for the long run, you need to consider ways to increase organic matter in the soil and build soil health.”

Key take-home tips:

• Wait to prepare the seedbed and plant when your soil is ready.

• Plan to monitor and maintain adequate fertility at key developmental stages for your crop. If you had to cut some fertilizer this year, check on crops early with plant tissue samples.

• Reduce plant stress with timely use of integrated pest management to control insects, weeds and disease.

• Consider the future with an investment in soil health.

Source: AgSource Laboratories