wiki

For a cover crop for the 2015-2016 winter season I chose a mix of oats and tillage radish. These aren't table radishes, rather they're more like the Daikon, which has a long root.

Tillage radish, raphanus sativus, also called forage radish, creates lots of leaves along with a root that goes deep into the subsoil. I planted beginning is mid-August and ending when the tomatoes and peppers were done.

Direct sown, the tillage radish germinated quickly and well. The oats were slower. They seemed to want to be covered before they would germinate. I worked all seeds into the soil wherever I could.

Both oats and tillage radish die with freezing temperatures, which is fine with me - dealing with a lot of biomass in the spring has slowed down planting at the farm. And weeds have been slow to develop during the winter.

The aim of using this mix is to get a lot of biomass into the soil and to drill down as deeply as possible. So I'm hoping for a reduction of compaction in the subsoil and the addition of organic matter.

The radish cover crop germinates and grows quickly, but the oat seeds are slower. The bare areas were only recently seeded as cash crops were harvested and composted. Both seeds require a good bit of moisture to get started and it works best for the oat seeds to work them into the soil, which I don't always do.

Because I sowed this cover crop as soon as I had completely harvested a section, hoping to accelerate the growing, sections sowed at different times had different germination patterns.

It appears that germination was most uneven in the earliest seeded sections - oats lagging greatly behind the radish. The section seeded latest had the most even germination but it failed to take hold before weeds and was not subject to winter kill (oats that survive the winter temperatures grow a tough root system that is difficult to till in the spring).

However, my early strategy of seeding soon allowed the a strong growth of radish which smothered many of the weeds. Germination of the oats was poorest in the early planting, which was among the newly mown buckwheat. Perhaps, the buckwheat shielded the seeds from sunlight and kept the soil cooler.

These results were different from those of spaced planting of crimson clover.