Agronomy Library > Soil Conservation

Direct Seeding in a Wet Spring
Author: Nick Underwood, Reduced Tillage LINKAGES
Date Created: April 24, 2007
Last Reviewed: April 24, 2007

Seeding in a wet spring can be a challenge, especially in soils with high clay content. Before the days of direct seeding there was often the light cultivation ‘to dry out the seedbed’. The first reason that was done was to enable the seeding operation. But, we know how valuable that moisture is. The second reason was more human, in that one could feel like you were actually doing something in the field. What you were actually doing was burning diesel, stimulating weed growth and wearing out equipment. You were also creating the need to do a pre-seeding harrowing operation, either at the same time, or after a couple of days drying time. To be fair, we did not have the same seeding equipment back then. Cultivating wet soils should be always be avoided. It can lead to compaction problems that inhibit moisture infiltration, and may show for several years.

We are often told that optimum yield comes from early seeding. I prefer the statement that optimum yields come from timely seeding.

Timely seeding is done when the soil conditions are right for the seeder that you have and the crop you wish to plant.

Seeding should not be done until the tractor and seeder can travel on the field without leaving obvious tracks and ruts, or picking up mud.

Because you have been a direct seeder for a few years, and your crop residue is evenly distributed over the field, you will be able to do this before, or at the same time as, you would have actually started seeding after the ‘drying out the seedbed’ operation.

The undisturbed roots of previous crops enhance internal drainage on the field and the soil is better aggregated (better structure). These are major advantages of not tilling. The soil will be saturated for less time. Residue on the surface also helps carry the tractor without picking up mud.

When seeding in damp conditions, the seed need only be as deep as is necessary to obtain soil cover over the seed. However, when double shooting, the fertilizer may be banded deeper than the seed.

High disturbance openers, with a high seedbed utilization and deep fertilizer placement, will be at a disadvantage, and will have to wait until conditions allow an acceptable job.

Disc openers or narrow knives, with lateral seed and fertilizer separation and low seedbed utilization, will be less likely to bring up lumps of clay.

Packing is very important. The seed furrow must be completely closed. This will not require much pressure if the ground is damp and a little soft. It does require on row packing.

Post seeding rolling, as a separate operation, is best done after emergence so as not to change the depth that the seed is below the surface. This operation may be necessary because the packers on the airdrill have left pronounced seed rows in the soft seedbed, and lateral travel is very rough.

The fields to be seeded should be selected on their relative dryness rather than crop type. That is a tough decision, but it is easier than getting stuck with a loaded aidrill in the middle of the field.

Seed shallow, and check seed placement often.