Post #23 Partnering with cover crops

What do you do when your feeling run down?  Some people need comfort food or a warm bath. Others sleep more or pop a packet of 'Emergen-C'.  As we mature, we all learn how to alleviate our own exhaustion.  We are not the only thing that gets run down and exhausted; we are a lot like soil in this respect.  As it turns out, our health and the health of soil are both influenced by the relative amounts of vitamins, carbon and water we contain.  When one of these gets thrown out of balance, bad things can happen.  To a gardener, exhausted soil looks like poor fruit production, sickly and discolored plants, and erosion.  The question then – and the topic of today's post – is: how do we recharge our soil?  How do we restore its vitality so that our crops thrive and be bountiful?  There are many soil conditioning methods, but one way in particular honors this month's thread of 'partnerships'.  Cover cropping.

A sick girl.  Like us, our soil can become run down and unhealthy.  Unhealthy soil needs attention and conditioning.  

Cover cropping is the act of planting beneficial plants in between cycles of crop plants.  Cover crops are diverse and plenty; rye, barley, various oats, clovers of all types, alfalfa, peas, buckwheat, reed canary grass, wheat, millet, soybean, vetch, kale, turnip and flax are just a few.  Each performs a unique job and benefits the soil in its own way.  For instance, rye is used through the winter to reduce erosion while barley 'scavenges' nitrogen from the soil (a good way to keep it from leaching or volatilizing).  Here is a great website that explains the various benefits of cover crops.  However your soil is acting run down, there is a cover crop that you can partner with to help it.          

This book is commonly referred to on the internet.  It is geared toward larger gardens and farms yet is still very informative and worth consulting if you are interested in managing your soil with cover crops.  

This spring and summer at the Armstrong House Education Center we used three cover crops to rejuvenate our garden's soil.

1) Peas (Pisum sativum).  Peas (along with the common clover, alfalfa and soybeans) are in the fabaceae or 'pea' family.  Like most plants in the fabaceae, peas are capable of taking gaseous nitrogen out of the atmosphere and converting it to a form of nitrogen usable by plants in a process called 'nitrogen fixation'.  You may have heard of this famous group of agricultural plants commonly referred to as 'nitrogen fixers' which actively increase the amount of nitrogen in the soil.  These plants provide us with an alternative to store bought, synthetic fertilizers, which have been shown to enter waterways and negatively effect aquatic ecosystems.

The flower of our pea cover crop.  Not only does this plant add nitrogen to the soil, it produces edible pea pods.  

2) Oats (Avena sativa).  These are called 'nurse' plants because they help the peas get established and grow.  The oats grow very quickly and suppress weeds while the relatively slower growing peas can develop and also act as scaffolding for the pea vines to grow upon.  After they die, the oats add carbon and nitrogen to the soil.  The peas and oats came together in this package.

3) Buckwheat (Fagopyrum esculentum).   This fast growing plant suppresses weeds and is good at scavenging soil phosphorus and calcium, thereby keeping it from being washed away.  I have found that many insects are attracted to the white flowers of buckwheat.  On warm summer days I was amazed to see well over a dozen species of flying insects working the buckwheat flowers.  Among them were the Armstrong honeybees, which will be supported into the nectar-limited fall by our abundant beds of buckwheat.  We currently use buckwheat from Botanical Interests.

How to manage cover crops?
Each cover crop is managed differently.  How/where/when to sow crops varies among the plants, as does growing time and method for killing.  Generally, we sow cover crops from seed allow them to live for a preferred amount of time and then kill them.  The plants themselves are either left to decompose in the garden or composted.

At the Armstrong House garden, I allowed our peas, oats and buckwheat to flower before turning them into the soil (roughly 6 weeks of growing time).  To reduce the amount of bulky organic material I had to work in, I cut and composted the top halves and allowed the bottom halves to decompose in place for 2 weeks.  After these two weeks, I chopped up the remaining stems into very small pieces and literally raked them into the soil as I sowed a new crop of buckwheat.    

Future cover crops?
After the current cycle of buckwheat is ready to turn into the soil we will plant crimson clover (Trifolium incarnatum) as a winter cover crop.  After germination, the clover will over winter in the garden and bloom in the early spring.  We choose this cover crop because it is a nitrogen fixer and a source of early spring nectar for our honeybees.

We will continue to use a variety of cover crops at the Armstrong House Education Center as we learn more about our soil's needs.  Think about what causes you to feel sick.  You make suffer from the flu, chicken pox, strep throat, arthritis, sciatica, or depression.  Each illness is remedied differently.  Likewise, in the future we may employ cover crops to perform different jobs such as erosion control, adding nutrients or organic material, honeybee forage or breaking up of compacted soil.  Check the blog or come to an event in our garden to see our current cover crop.