Anne Verhallen, Soil Management Specialist – Horticulture, OMAF & MRA, Ridgetown
Seems like this year there can be lots of reasons for an open field in mid- summer from water damaged fields of sugar beets or tomatoes to wind and storm damaged seed corn to wet harvested peas or snap beans. They all pose some problems and also some opportunities. Now what?
- The obvious stuff of course – wait for the field to dry enough to allow you to fill in any ruts. Work the field to open up the soil, particularly any areas that have had standing water.
- The less obvious stuff – plant a cover crop to tie up nitrogen, control weeds and rebuild soil structure.
Cover crop options depend upon the cropping plans for 2014 and how long it may take to get the field in shape:
- Planning to plant winter wheat there this fall? You need a fast growing cover crop like oilseed radish or possibly buckwheat that can be established by early August, not cause weed concerns in the wheat and will achieve good growth in the 6 weeks before destroying the cover crop and planting wheat.
Oats and oilseed radish can make a great cover crop combination. If fall conditions allow, there can be tremendous growth, have a plan in place to deal with the residue. - If you expect to be planting in August, consider oats or an oat/oilseed radish mixture. Sugar beets and oilseed radish, tillage and compaction do not support mycorrhizae. Many of our crop plants do support and benefit from mycorrhizae. The oats in this cover crop mixture will help mycorrhizae to re-establish. Both oats and oilseed radish will grow
Oats and oilseed radish complement each other as cover crops with the fibrous root system of the oat and the tap root of the oilseed radish and both will die over winter. rapidly in the cooler weather of late summer and early fall and then die over winter. This mixture combines the tap root of the oilseed radish with the fibrous root of the oats.
- Planting won’t happen until September? Start thinking about winter cereals like wheat, rye or triticale. Oats and oilseed radish will give good growth usually until the first week or so in September but after that it is time to switch to the more cold tolerant winter cereals. However, be prepared to manage these grasses in the early spring before they start to grow quickly.
A multi mixture of cover crops can include warm season grasses like sorghum sudan which are killed by early frosts while the oats and oilseed radish tolerate fall temperatures readily. - If you are more adventuresome and can plant in early August, a field of this type is a good option for a cover crop mixture. There is the option of mixing warm and cool season cover crops in a multi mixture. With at least 6 weeks of warm weather left and the possibility of an open fall, there is the potential for tremendous growth. A multi mixture lets you get several different types of root systems and plant structures into the cover crop. This year, for our after wheat project, we are trying a mixture of clover, peas, oats, sorghum sudan, oilseed radish and a small amount of sunflower.
