Thursday, February 2, 2012

What's New at the Farm? Passionate About Cover Crops

Clover growing under a canopy
of corn as the author suggests
One of my passions in farming is the use of cover crops. Both here at Johnny's farm and in my own garden I use cover cops to protect and enrich the soil. I'm much more devoted to planting and maintaining cover crops here on the farm than I am at home. Here we have all the right equipment to prepare the soils, plant, mow and incorporate crops as we see fit. At home I'm sorely lacking the array of equipment I have at my disposal here so while things are a little different there, the goals remain the same; cover crops are important, regardless of the size of the plot of soil, to protect and enrich the soil.

Cover crops in the garden function much the same as in a farmer's fields; they hold the soil, bring up nutrients from deep within the ground, and add organic matter and, in some, cases nitrogen to feed subsequent crops. Cover crops for the home garden – that's my topic today.

My garden at home is 75 by 150 feet. -- about a quarter acre. The soil is clay on top of ledge. For many years it was a hayfield; poorly maintained and hardly any fertilizer or organic matter was ever applied. When I bought the field, I picked out this garden spot as it was the only relatively flat area in the three acres. I immediately started adding lots of organic matter by way of leaves and manure from my chicken pens. My neighbor came down and moldboard plowed it for me the first year to bury the soil amendments and the sod. I seeded my plot down to oats.

Why oats? Oats will grow almost anywhere and at nearly any time of year. I needed a crop that would shade out the weeds and the sod, add organic matter and be relatively maintenance free.

Because of the large amounts of nitrogen from the chicken manure I felt I didn't have to add a legume for nitrogen production. Legumes make their own nitrogen (N); they don't need it or particularly like a lot of N. Oats will take up many nutrients including N and are very good at recycling them. I had planted the oats in August, so I left them intact for the winter. The following spring, as the oats had died, I had them tilled under along with another liberal dose of chicken manure. That second year I planted some vegetables in my garden. 
Routine additions of organic matter benefits the garden immensely. Adding compost is great, but on a garden of size it can easily turn into a large expense and a lot of work. There are many demands on my time and the thought of spending so much time and money applying compost every year, well, you get the picture.

I think the ideal situation is to cover crop half of the plot one year and rotate my garden the next.

Growing cover crops not only protects the soil but much of that organic matter I'm talking about can be had through the use and growing of cover crops. It's much easier, and a lot cheaper, to grow  organic  matter than buy and bring it in. Of course the crops that add the most organic matter will also have the most "materials" to incorporate back in to the soils and many of these would be difficult in the home garden setting.

Getting a cover crop in before planting my garden is pretty much impossible. The season is short enough as it is, so I'd rather get the soil drying out and the planting in early than try to push the time envelop to get a crop in and turned under before I plant another crop. In some instances, like planting fall crops, it is possible but it takes some management to make this happen and be worthwhile. In my garden, where I'll plant late crops, I'll do some weed control on these plots instead of trying to get a cover crop in prior to an edible crop. As the crops mature and are turned back into the soil, I spend the time needed to get some cover crop or organic matter addition done before fall starts.

Crops easy to turn under with a limited selection of tools:
  • Buckwheat -- Till in at most any stage, buckwheat will die and wilt rapidly on a warm, summer day. Not the best for adding lots of organic matter, but easy to grow and incorporate, and several crops can be grown in one season. Excellent for "smothering" weeds.
  • Annual Alfalfa -- If you indeed do need nitrogen, annual alfalfa winterkills and is easy to turn under in the spring.
  • Oilseed radish –- If planted midsummer, it will grow large roots during the cool fall months. During winter the plants will die and the roots will rot, so tilling them under in the spring will be relatively easy.
The most important things to remember with cover crops in the home garden:
  • Protect the soil before winter or when not in use for any large block of time.
  • Plant a crop that is easy to maintain and will till in easily when you want to.
  • Think about rotating part of your plot out each year to help break disease and pest cycles, and to add organic matter.
  • Interplanting is a great way to get two crops in the space one takes.

So, back to my garden. In the second year I planted sweet corn in one corner, and around the fourth of July underseeded it with Crimson Clover. The clover grew well in the understory of the corn, and once I mowed the corn stalks, grew rapidly the rest of the season. And last year I fallowed the garden to kill off some of the harder to control weeds that have gained a foothold. And this year I plan on planting about half the space and planting a cover crop on the other half. And so it goes.

Until next week, Brian


Anonymous said...

Till, till, till...mostly not necessary. Continued tilling breaks down soil structure and reduces the value of adding the organic material. Johnny's sells a great broadfork--why not use it?

David said...

Your point is well taken! We can't quite broadfork our average 80-acre annual production on the farm, but a garden with the right cover is much easier to manage with light tillage methods.