Published Sep 15, 2011

Flying on cover crops in dry conditions

By Sarah Carlson

I just wanted to give a heads up to all those folks thinking about
flying on cover crops right now. I know that it might be too late to
get the message out but we are just not getting the rains needed
across the majority of the state right now and we were already dry in
many areas that at this time successful establishment of cover crops
using a plane might be risky.

We have seen winter rye cover crop seed sit on the soil surface for up
to 3 weeks and then catch a rain and have good establishment. But
thinking about the fall low moisture condition from last year I am
concerned that the cover crops flown on now will have a challenge to
get established. The following suggestions are for establishing a
winter small grain cover crop. Legume establishment at this time to
have fall growth is riskier than a small grain, like winter rye or
winter wheat.

Some options:
1) If you’ve already flown on your cover crop then following fall
harvest you should observe the soil to seed contact and where
appropriate pack or roll the seed to push it into the soil. That will
improve soil to seed contact and with what little moisture there is in
the soil surface will help get the cover crop seed germinated. Then we
will just need to hope for rainfall to sustain growth.

2)If you are planning to overseed using a plane or highboy and you
have a shorter season hybrid you might want to wait to no-till drill
the seed into the ground following grain harvest. That will improve
soil to seed contact. To save soil moisture do not disturb the soil
and just plant the cover crop seed directly.

3)If you are planning to overseed using a plane or highboy and have a
while until grain harvest happens (1month or more) then timing with
moisture will be critical. If rain is in the forecast them fly the
cover crops on; If your fields have enough soil moisture then fly it
on; If you are very dry (no rain since sometime in July) and there is
not any forecasted rainfall for the next couple weeks then I would
re-think flying it on. If you can irrigate then the problem is solved
and plan to do that.

4)If you will be planting the cover crop after grain harvest—-and
your soil is dry and limited rainfall is forecasted—do NOT till
before planting. By no-till or drilling the seed directly with
disturbing the soil surface you will improve the chances of
establishment by saving any soil moisture there is in the top couple
inches of the soil. That little bit of soil moisture last fall made
the difference between our field in Boone getting good establishment
when no-till drilled versus a neighboring farmer’s field with no fall
growth when the cover crops were planted at the same time but after
disturbing the soil.

If your cover crop seed (winter rye, winter wheat and usually hairy
vetch) does not germinate this fall don’t worry they will usually come
back in the spring. But no fall growth and winter soil protection from
the cover crop will be present.

Let me know if you have any questions and please try to share your comments.

Thanks and lets hope for some rain soon.