Wednesday, November 30, 2011

Composting 101

Over the course of several postings I’ll tell you all I know about composting.  I won’t claim to know everything but I have been actively composting for at least forty years so I do know quite a bit. Much of what I have learned through experience and experimenting does not agree 100% with what many other “experts” will say.  So, as in all things, you’ll have to read what I write and do some research on your own, and then decide what works best for you.

As most of you know I am a Soldier and have been on active duty since February 1983 and was in the PA National Guard for five years before that.  So I move quite often; on average about every 34 months.  Even so, with a few exceptions, I have continued to have at least a small garden and to make and use compost in my gardens.

So what exactly is compost?  Very simply it is organic material (anything that was once living) that has been allowed to biodegrade through microbial action. In other words, it has rotted. During the composting process, various other life forms (worms, insects, bacteria, fungi) eat and digest the organic material (leaves, grass, sawdust, food scraps, etc.) and then excrete their own waste products.  As well, most of those life forms go through their own accelerated life cycle and the compost contains their decomposing bodies. It is mostly the digestive process of the micro-animals and the colonization of various fungi and bacteria that produce the nutrients contained in the compost.

Think of it this way.  What is the difference between the grass, hay, and grain that a cow eats and its manure?  Mostly - the inclusion of the stomach acids and the intestinal bacteria (which also adds nitrogen).  Otherwise it is the same stuff coming out as went in.  There is no transmutation of elements (alchemy) involved here.

There are several different methods of composting but only two major processes; aerobic composting and anaerobic composting.

Aerobic means “with oxygen” and anaerobic means “without oxygen”. For our purposes we will only talk about aerobic composting but I’ll briefly explain anaerobic composting here.

Anaerobic composting is also sometimes called “digestion” because that is what happens in the stomach and intestines of animals.  A completely different class of bacteria is involved in anaerobic digestion; they can only live in a low or no-oxygen environment.  By-products of anaerobic digestion are such things as methane gas and sulfur-dioxide; the two principle parts of flatulence. In a controlled environment, organic materials can be turned into energy by use of a “methane digester”, a large anaerobic composter that produces large amounts of flammable methane gas, which can be used to run an electric generator for instance. Suitable for large dairy farms perhaps, but not so much for the back-yard gardener.

Aerobic composting is what we are interested in. All organic material will break down, decompose, over time.  But what we want to do is speed up the process and retain the resultant nutrients.  This requires intentional composting.

Efficient composting requires five things: 1. Carbon-rich material (the food); 2. Nitrogen-rich material (the energy); 3. Moisture (all living things need water); 4. Oxygen (the life forms we are interested in must breath oxygen); 5. Heat (life processes slow down when cold).

Let’s look at each of these:

Carbon-rich material. These are often referred to as the “brown” components of compost.  Carbon-rich materials are such things as dead leaves in the fall, straw, wood chips and sawdust, shredded paper and cardboard, and other dead, dried out plant material. This material will be the bulk of your compost pile; in fact it should be at a 30 to 1 ratio with the Nitrogen-rich material. The carbon-rich material provides the food and shelter to the various life forms in the compost pile. They also create the air spaces needed to maintain a suitable level of oxygen in the pile. Fungi and bacteria will immediately colonize the “brown” material and start to break it down into its chemical component parts.  It is this fungi and bacteria smorgasbord that attracts slightly higher life forms such as insects, worms, and other microbes

Nitrogen-rich material. These are often referred to as the “green” components of compost. Nitrogen-rich materials are such things as animal manure and urine, green grass clippings, green plants and leaves, and kitchen scraps.  This green material provides the energy the various life forms in the compost pile need to maintain there digestive activity.  Too much green material in a compost pile, such as a huge pile of green grass clippings, and bacteria immediately use up the oxygen and die off.  The pile is then colonized by anaerobic digesters and you end up with a slimy, smelly pile of goo. Green material should be at a 1 to 30 ratio with the brown material. 
Moisture. All living things need water to survive but too much water is no good.  Too much water in a compost pile fills in the tiny air spaces and suffocates the living organisms. Likewise, if the compost material is too dry the composting process will slow down or halt. Your compost material should be about as moist as a wrung out sponge.  If you can squeeze water out of the composting material, it is too wet. If it is too wet you can do a couple things. One is to turn the pile to mix the drier outer layers with the wetter inner layers.  Hopefully this will balance it out. Or, you can add more dry materials to soak up some of the moisture. If the compost pile is too dry, you can spray it with water while you turn the pile to moisten the material evenly. REMEMBER-chlorinated water will kill microbial organisms.  You don’t want to do that.  So if you are on chlorinated water you will need to fill up buckets or a kiddy pool with water and let it sit out in the sun for a couple days to de-chlorinate.

Oxygen. Not all living things thrive on oxygen but the ones we are interested in do.  Therefore the more oxygen you can get into the pile the better.  This is most often accomplished by “turning” the pile.  I have a four bin compost set-up so turning the pile is as easy as forking it out of one bin and into another.  As I do this I shake and “fluff” up the material so there is lots of air space in between. DO NOT pack down your compost pile.  It will settle on its own but what you really want is lots of open space in the material.  The more often you turn your pile the faster it will compost (all other things being equal).  That is the purpose and success of the rotating compost barrel systems you can buy.  Each day you go out and turn the crank a couple times and the compost is aerated. 
Heat. Most living organisms prefer to be warm as opposed to being cold.  The micro-organisms in your compost pile are no different.  The heat given off by the billions (trillions?) of micro-organisms in your compost pile will heat the material up to over 120 degrees and depending on the materials and oxygen content even up to 150 degrees. This is desired because it helps to kill weed seeds and other undesired pathogens. In the summer it is not too hard to keep the pile warm, although normal evaporation of the moisture from the pile will tend to cool it down quite a bit.  In the winter, especially if you live in the north, it is difficult to maintain any warmth at all and the composting process crawls to a stop.  Deep inside the pile there is probably still some activity though. You can increase the heat by ensuring there is a proper Brown to Green ratio, by frequently turning the pile to add oxygen, by placing the pile in a sunny location, and by wrapping the pile in clear plastic in the cooler months.

Monday, November 28, 2011

Think Things are Bad Now? Just Wait!

ROME (AP) — The United Nations has completed the first-ever global assessment of the state of the planet's land resources, finding in a report Monday that a quarter of all land is highly degraded and warning the trend must be reversed if the world's growing population is to be fed.

The U.N. Food and Agriculture Organization estimates that farmers will have to produce 70 percent more food by 2050 to meet the needs of the world's expected 9 billion-strong population. That amounts to 1 billion tons more wheat, rice and other cereals and 200 million more tons of beef and other livestock.

But as it is, most available land is already being farmed, and in ways that often decrease its productivity through practices that lead to soil erosion and wasting of water.

That means that to meet the world's future food needs, a major "sustainable intensification" of agricultural productivity on existing farmland will be necessary, the FAO said in "State of the World's Land and Water Resources for Food and Agriculture."

FAO's director-general Jacques Diouf said increased competition over land for growing biofuels, coupled with climate change and poor farming practices, had left key food-producing systems at risk of being unable to meet human needs in 2050.

"The consequences in terms of hunger and poverty are unacceptable," he told reporters at FAO's Rome headquarters. "Remedial actions need to be taken now. We simply cannot continue on a course of business as usual."

The report was released Monday, as delegates from around the world meet in Durban, South Africa, for a two-week U.N. climate change conference aimed at breaking the deadlock on how to curb emissions of carbon dioxide and other pollutants.

The report found that climate change coupled with poor farming practices had contributed to a decrease in productivity of the world's farmland following the boon years of the Green Revolution, when crop yields soared thanks to new technologies, pesticides and the introduction of high-yield crops.

Thanks to the Green Revolution, the world's cropland grew by just 12 percent between 1961 and 2009, but food productivity increased by 150 percent.

But the U.N. report found that rates of growth have been slowing down in many areas and today are only half of what they were at the peak of the Green Revolution.

It found that 25 percent of the world's land is now "highly degraded," with soil erosion, water degradation and biodiversity loss. Another 8 percent is moderately degraded, while 36 percent is stable or slightly degraded and 10 percent is ranked as "improving."

The rest of the Earth's surface is either bare or covered by inland water bodies.

Some examples of areas at risk: Western Europe, where highly intensive agriculture has led to pollution of soil and aquifers and a resulting loss of biodiversity; In the highlands of the Himalayas, the Andes, the Ethiopian plateau and southern Africa, soil erosion has been coupled with an increased intensity of floods; In southeast and eastern Asia's rice-based food systems, land has been abandoned thanks in part to a loss of the cultural value of it.

The report found that water around the world is becoming ever more scarce and salinated, while groundwater is becoming more polluted by agricultural runoff and other toxins.

In order to meet the world's water needs in 2050, more efficient irrigation will be necessary since currently most irrigation systems perform well below their capacity, FAO said.

The agency called for new farming practices like integrated irrigation and fish-farm systems to meet those demands, as well as overall investment in agricultural development.

The price tag deemed necessary for investments through 2050: $1 trillion in irrigation water management alone for developing countries, with another $160 billion for soil conservation and flood control.

Learn now how to produce your own food!
It is only going to get worse in the coming years.

Sunday, November 27, 2011

Winter is Coming - Gardening is Done?

When fall came and the edible plants started dying off from frost - my family's garden, and our neighbors' gardens, were pretty much just abandoned and left alone through the winter. Weeds, much hardier than tomato plants, continued to grow and set seeds.  These fell onto the soil and were next year's weed problem. What I have found is that a bit of laziness in the fall and winter causes you to do much more work the following spring and summer.  What can/should you do in the fall and winter?

1. Thoroughly weed your garden and remove all old plants (throw them on your compost pile). Any plant pests you had will "over winter" on the plants they infested during the growing cycle. You don't want them to survive the winter and begin their life cycle again in the spring. Throw your plants in the compost pile so any residual nutrients can be recycled back into your garden.

2. Before it freezes, screen and turn your compost pile. I have a four bin composting set-up at my house in Pennsylvania. Each bin is 4x4x4 feet, so it holds 64 cubic feet of material. One bin holds finished compost, one bin holds raw materials, one bin is actively composting, and right now the fourth bin is empty.

Once or twice a year I dig out the active compost bin and sift all the semi-composted material through a screen.  The screen is 1/4" hardware cloth over a 2x3 frame.  I shovel the partially composted material onto the screen, give it a few shakes, and the finer material falls through to my wagon.  The uncomposted, larger material gets tossed into an open bin. By the time I have screened the entire bin I usually have a full wagon of fine material (20 cubic feet) and another bin 1/3 full of material that has only begun to break down. This will now be the bottom layer of my next batch of compost. This will be the "worm layer" since worms will quickly move up into this layer of "worm food".

    Next I run the raw material through my mulcher/chipper with the screens removed (or it clogs up real easy) and throw this stuff in the partially filled bin. This will usually fill the new bin close to the top. I'll cover this bin with something water proof (I use old shower curtains and picnic table table cloths) and it is good to go for the winter. Since it was freshly aerated the pile will start to heat up from the biologic activity of the composting process.  But once it starts going down below freezing at night that will slow down and eventually almost stop.  That's ok, it is just dormant; once it warms up in the spring the composting process will start up again.
    The fine material that I screened out will go in the finished compost bin if there is room or it will go directly into the garden.

3. Till under your garden. Many plant pests in your garden will lay their eggs in the soil, on the plants, or the pest is in the larva or grub stage living just beneath the surface of the soil.  Tilling the soil, by machine or by hand, will disrupt the life cycle of these pests.  Some will be buried too deep to survive, some will be exposed to killing freezes, and some will be killed by the tilling process.  You won't get rid of all of them but you will greatly reduce their numbers.

Tilling-under leaves
Once I have removed all the old plant material, I spread a one inch layer of compost on the garden and all the leaves I can rake up. I have a DR Leaf and Lawn Vacuum system but there are lots of other brands out there that are just as good or better.  If you have a smaller yard (mine is 3.1 acres) you can just use a rake. The lawn vacuum I have runs the sucked up leaves and grass through a mulcher and blows that into a wagon behind my lawn tractor so it is even easier to work into the soil. 


Soil loaded up with Fall leaves
Soil biological activity will slow down during the winter but it doesn't stop. Loading up the soil with organic material in the fall will allow most of it to bio-degrade over the winter.  If you put all this into the soil in the spring it would tie up all the nitrogen in the soil and your plants would suffer. The micro-organisms that break down organic material into plant food use many of the same nutrients that plants need to grow. The high level of organic material also helps the soil to resist erosion either from the wind or rain. If you use raised beds, and I always recommend raised beds for home food production, this will refill the beds.  

Lastly, after all the previous is done, I like to put down a thick layer of top mulch (usually ground up leaves and grass) to cover the growing bed.  This helps to moderate temperature swings in the soil and usually keeps it from freezing down below 2-3 inches. That keeps the worms happy and if your soil has happy worms, you have good soil.

This process gives you the opportunity to clean up your yard, put that yard waste to good use, fertilize your garden soil for free (I rely 100% on compost, I never buy fertilizer), and makes the garden look nice for the winter.  Come spring, all you need to do is uncover the garden so it can warm up and then plant.  No tilling should be needed and therefore the worms and other soil organisms are not disturbed. One technique I have used successfully is to leave the top mulch on the garden but cover the garden with clear plastic sheeting to warm it up.  This way I have a pre-mulched garden.  I lay down planks or square paver stones to make my walkways between the beds. I have a mix of raised beds and open, traditional garden space.  But I use the traditional garden space as if it were raised beds by laying in the walkways.

Don't have a compost facility yet?  What are you waiting for?

Composting can be very easy, just easy, a bit of a chore, difficult, or a full-time job. I would have to rate my method as "a bit of a chore" because I am only home four weeks out of the year right now. Composting is a big subject area so I will devote my next posting to the art and science of Composting

The simpliest of composters is nothing more than this.