Blog

Been quite this spring in Illinois. Spring came early in March, but then disappeared for a few weeks when it turned cold, snowy and wet. Well, spring is back now and appears ready to stay, so it’s time to plant.

CCA Soy Envoy and Monsanto Agronomist Lance Tarochione blogged earlier on planting date and when to plant soybeans. Two things we know are that soybeans are being planted earlier and growers are equipping themselves to plant soybeans when they are planting corn. I think that is a good decision and growers are capturing more bushels by doing so.

Soil temperature is less important. For a long time planting was driven by soil temperature, followed by soil conditions. Growers can remember when corn was planted after soil temperatures were above 50⁰ F and trending upward and for soybeans, above 55 to 60⁰ F, which was easy to achieve since you planted after corn planting was done. But today soil temperature is less important and soybeans are being planted at the same time as corn. We can thank better seed, better genetics and good seed treatments for making this possible.

So with today’s genetic and seed technology the calendar date seems to be the driver more than exact soil temperature.

While soil temperature is no longer very important, soil conditions still are. No wants to mud up their row units, compact the soil surface or create sidewall compaction.

Plant in ideal soil conditions. Ideal soil conditions are just as important for planting as they were for doing spring tillage. If the soil is too moist, not only will wheel traffic cause compaction, but discs will smear the soil, causing sidewall compaction in the V-furrow that will impede root growth of young seedlings.

Soil must be crumbly and friable. Larger aggregates, clods or peds can be broken apart easily and moisture never glistens on your fingers. The factor that affects friability is soil moisture. The moisture content for working a field varies with the soil texture and with the tool being used. Soil moisture needs to be in the right range not only at the surface, but right down to the depth of soil disturbance.

Do not plant in a saturated soil. Soil needs to be mellow and have good structure. Seed furrows need sidewall structure, but not sidewall compaction.

Wait until conditions are ideal. If growers work or traffic soil with high moisture conditions, it will create a cloddy soil surface and will not be a good seedbed. Moisture is always the best indicator of when to work a soil. Soil moisture acts a lubricant, enables particles to slide and compact, raises bulk density, makes it difficult for roots to penetrate, and reduces aeration and infiltration.

Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at djdavidson@agwrite.com.