Cover crops have been around for a number of years, but are still being explored as options for soil improvement. Reported benefits include nutrient recovery, reduction of compaction and enhanced soil health by providing an environment for beneficial microbes. The NCRS has had cover crops for years following wheat harvest. Just don't have enough time after soybeans and corn. Admittedly we haven't done a great deal of work on cover crop mixture testing. Usually a blend of oats and tillage radish is planted. Here is a strip from a fertilizer test where plant establishment was poor. Can you guess why?
Well it seems that a soil amendment in the form of 300 lb/A of muriate of potash was spread and lightly incorporated (vertical tillage) prior to planting. This picture was taken in late September a little over a month after planting. On either side is 100 lb/A of potash in this field with very low soil test potassium. We will follow it next year with corn plots. Interesting result though.
Over on Farm 7 we are having a comparison of some different tillage and cover crop combinations. Compaction is a problem at the NCRS when you work with plots that have lots of traffic in the form of planting, spraying, foliar apps, combine and grain cart/weigh wagon. So often the ground will be ripped and then planted to cover crop when wheat is in the rotation. There are four replicated treatments, again following wheat. (You may see some frosted corn from where the weigh wagon was cleaned out after corn harvest plus spread seed from old partial bags of corn. This area is normally not plot ground.) These are long strips going up and over that hill in the background.
This strip was ripped only. (A ripper is a tillage tool with shanks that go deep into the soil to break up compaction zones. You can see the strips where these shanks ran. The soil needs to be rather dry in order to shatter the compaction zone.) No cover crop, that's volunteer wheat. These pictures were taken on November 8 and were planted in early September.
This strip had no tillage and no cover crop, other than this volunteer wheat.
This strip had no tillage, but had annual ryegrass and tillage radish. Unfortunately the ryegrass didn't get off to a very good start. We are testing this as I have been told by others that the ryegrass will root down deep enough to break up compaction, especially in combination with the radish. So we will monitor these strips through corn harvest next year. And there are four replications of each of these.
