Here is a link to a cover crop story in Organic Gardening: http://www.organicgardening.com/feature/0,7518,s1-3-81-789,00.html
Again, anybody with any knowledge about this gardening practice, I urge you to chime in.
As an aside, I am privy to some of the goings on at the Rio Grande Community Farm regarding cover crop studies. I'll let you all know as soon as I know how things came out.
Showing posts with label cover crops. Show all posts
Showing posts with label cover crops. Show all posts
Friday, December 10, 2010
Thursday, July 29, 2010
Cover Crop Conversation Continued
A question was raised concerning the previous blog entry/email.
I have a question on the cocktail mix. It's my understanding that most cover crops are harvest/cut/flailed, etc.
sometime between the start of flowering and halfway into bloom. With a cocktail, how do you determine the optimum time to take the cover crop down? Is it the flowering schedule of the earliest member of the mix?
The average point of all of them?
And the answer:
Most of our farmers terminate the cover crop with winter kill, meaning it is allowed to fully develop. Before moving into soil health we terminated all sunlight harvest after grain harvest. Now we use the cover crops to harvest the sunlight from grain harvest to winter. This sunlight ultimately becomes additional carbon in the soil. Making increases in soil organic matter more achievable. We have built soil health based no-till systems on the cropland and grazing systems on the rangeland, then the cover crops are used as a bridge to connect the cropland and rangeland. We try for a continual live root, just like native rangeland has. The livestock are a tool to harvest 40-50% of the cover crop biomass, leaving the remainder as soil armor. The livestock can also be used to terminate cover crops by mob grazing. I have attached pictures showing what the soil cover looks like before
and after
having 750,000 lbs of beef per acre graze a cool season cover crop cocktail. Our local Soil Conservation District also has a crop roller which is used to terminate rye or field pea.
We rolled the pea during bloom and the rye during 50%+ anthesis, both were seeded as monocultures. Occasionally we have farmers who terminate a cover crop mixture with herbicide, but only rarely with tillage.
I have a question on the cocktail mix. It's my understanding that most cover crops are harvest/cut/flailed, etc.
sometime between the start of flowering and halfway into bloom. With a cocktail, how do you determine the optimum time to take the cover crop down? Is it the flowering schedule of the earliest member of the mix?
The average point of all of them?
And the answer:
Most of our farmers terminate the cover crop with winter kill, meaning it is allowed to fully develop. Before moving into soil health we terminated all sunlight harvest after grain harvest. Now we use the cover crops to harvest the sunlight from grain harvest to winter. This sunlight ultimately becomes additional carbon in the soil. Making increases in soil organic matter more achievable. We have built soil health based no-till systems on the cropland and grazing systems on the rangeland, then the cover crops are used as a bridge to connect the cropland and rangeland. We try for a continual live root, just like native rangeland has. The livestock are a tool to harvest 40-50% of the cover crop biomass, leaving the remainder as soil armor. The livestock can also be used to terminate cover crops by mob grazing. I have attached pictures showing what the soil cover looks like before
and after
having 750,000 lbs of beef per acre graze a cool season cover crop cocktail. Our local Soil Conservation District also has a crop roller which is used to terminate rye or field pea.
We rolled the pea during bloom and the rye during 50%+ anthesis, both were seeded as monocultures. Occasionally we have farmers who terminate a cover crop mixture with herbicide, but only rarely with tillage.
Cover Crops
The following is excerpts from an email conversation concerning cover crops for a local organic farm. I am finding it very useful as this particular aspect of sustainable farming is difficult for me to understand.
Your first attempt at planning a cover crop mixture is very good. As I recall some of the resource concerns included armor (surface residue), crop diversity, soil aggregates, nutrient cycling, and infiltration to name a few. I see the mixture consists of cool season broadleaves and cool season grass, which is what we would use here for a fall seeding after harvest. The high carbon portion appears a little high, with the first 4 species making up 50%, while the legume may be a little low at 30% of the mix. I would suggest decreasing the high carbon to 40% and increasing the legume to 40%. Possibly an additional legume could be added, such as Lentil. The brassica portion at 20% looks good, since they are nitrogen scavenging and low carbon you do not need very much. The high carbon will give you soil armor and their roots will improve the soil aggregates and soil organic matter. The legumes will improve the nutrient cycling, while the brassicas create streets and avenues for the water to move into the soil profile. Improving soil health is about restoring balance, and the cover crop mixtures will help you with this task. Always try to include crop types in the cover crop mixture that are not used in the annual crop rotation, this will improve crop diversity and help feed the soil biology a more balanced diet.
I attached two cover crop pictures too.
[The photo above depicts] a 14-way mixture, which is primarily cool season. It was seeded at the Menoken Farm on May 12 and includes: wheat, oat, forage pea, lentil, ac greenfix, turnip, radish, sunflower, Italian rye grass, hairy vetch, sweet clover, phacelia, canola, and flax. The native pollinators did very well with this mixture too.
[This photo is] a primarily warm season 11-way mixture, and was seeded on June 14th at the Black Leg Ranch. It consists of: pearl millet, proso millet, sudan, soybean, cowpea, sunflower, radish, turnip, sweet clover, canola, and corn. Both are based on the clients resource concerns and objectives. This is not the first time that nature has seen this many different plants together. We have to understand they are working together and not competing. Thank you for your interest in soil health.
I have used this email without permission from it's author but thank him nonetheless.
Your first attempt at planning a cover crop mixture is very good. As I recall some of the resource concerns included armor (surface residue), crop diversity, soil aggregates, nutrient cycling, and infiltration to name a few. I see the mixture consists of cool season broadleaves and cool season grass, which is what we would use here for a fall seeding after harvest. The high carbon portion appears a little high, with the first 4 species making up 50%, while the legume may be a little low at 30% of the mix. I would suggest decreasing the high carbon to 40% and increasing the legume to 40%. Possibly an additional legume could be added, such as Lentil. The brassica portion at 20% looks good, since they are nitrogen scavenging and low carbon you do not need very much. The high carbon will give you soil armor and their roots will improve the soil aggregates and soil organic matter. The legumes will improve the nutrient cycling, while the brassicas create streets and avenues for the water to move into the soil profile. Improving soil health is about restoring balance, and the cover crop mixtures will help you with this task. Always try to include crop types in the cover crop mixture that are not used in the annual crop rotation, this will improve crop diversity and help feed the soil biology a more balanced diet.
I attached two cover crop pictures too.
[The photo above depicts] a 14-way mixture, which is primarily cool season. It was seeded at the Menoken Farm on May 12 and includes: wheat, oat, forage pea, lentil, ac greenfix, turnip, radish, sunflower, Italian rye grass, hairy vetch, sweet clover, phacelia, canola, and flax. The native pollinators did very well with this mixture too.
[This photo is] a primarily warm season 11-way mixture, and was seeded on June 14th at the Black Leg Ranch. It consists of: pearl millet, proso millet, sudan, soybean, cowpea, sunflower, radish, turnip, sweet clover, canola, and corn. Both are based on the clients resource concerns and objectives. This is not the first time that nature has seen this many different plants together. We have to understand they are working together and not competing. Thank you for your interest in soil health.
I have used this email without permission from it's author but thank him nonetheless.
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