Applied Geography formerly Rural Training Center, Thailand

2010 Jan 07 RTC-TH Programs: C.O.M.P.O.S.T.

Jan 07, 2010

C.O.M.P.O.S.T. (Creating Our Most Precious Organic Soil Treatment) is about making compost. Compost is not fertilizer.

The lessons and activities in this program range from an awareness of the advantages of compost to various composting methods. Basic soil testing is taught so farmers can monitor soil conditions to see the effects of composting on their farms.

Among the advantages of composting are: reduction of burning and associated air pollution; reduction of landfill bulk; reduction of unsanitary conditions associated with garbage piles. The sustainable agricultural values of compost include reduction of off-farm expenses for synthetic agricultural chemicals; improved soil structure, erosion resistance and moisture retention; and generally healthier soil conditions for crop production. If less synthetic agricultural chemicals are used, water pollution is also reduced. Amazingly, all of these benefits come from making better use of materials that might normally be thrown away. And best of all, it is generally free. It takes time to make the compost pile, but then nature does most of the work to convert the ?“garbage?” into a valuable organic soil additive.

It is important to know that compost is NOT fertilizer. Soil fertility is based on making the soil nutrients available for plants to use. It is the chemical processes that make soil ?“fertile?”, not just the amount of nutrients in the soil.

The ingredients for making compost are basically carbon, nitrogen, water, air, and some bacteria. Carbon is readily available in any dead plant materials: brown leaves, newspaper, and cardboard. Nitrogen is found in green plant materials: green leaves and fresh cut grass. The bacteria can come from soil or animal manure (most commonly cow, horse, pig, chicken, and ducks). Composting uses nature?’s way to break down plant materials to recycle them.

In a forest, leaves fall to the ground and pile up. Rain adds water. Birds and other forest animals and soil bacteria reduce the leaves to their basic elements. Ultimately these are worked into the soil. When people make compost, they are trying to speed up this natural process by bringing all the ingredients together in just the right amounts. The good thing about composting is that it is hard to NOT make compost. Even if your compost pile is not ideal, the natural processes still go on and decay takes place.

When making a compost pile, find a spot that is not too shady and not too wet. The pile should get exposed to sunlight for a good part of the day. The ground should not be flooded or wet. The bacteria and organisms helping in the composting process need food, air, and water. Pile them loosely to let air circulate throughout the materials. As time goes on, the pile will naturally ?“shrink?”. Alternate layers of carbon, nitrogen, manure. Sprinkle some water on each layer. A good ratio of brown to green is done by weight. The brown (carbon) material tends to be lighter than the green (nitrogen). Green plant materials have more water in them. [Note: Other than hair, feathers, and egg shells, we tend to not use animal materials (e.g. grease, fat, oils, bones). Plant materials tend to break down faster. Oils and fats slow the process and tend to attract ?“undesirables?” to our compost piles (e.g flies and vermin).

Composting Methods
The different composting methods we use are: hot piles, cold piles, trenches, sheet, and worm composting.

Hot Compost Piles: This is the fastest way to make compost (3 months or less depending on the conditions). But is it the most labor intensive. You need to monitor the compost pile and make adjustments to keep it at the optimum operating condition. We don?’t recommend this method for the very young or the elderly.

Cold Compost Piles: This is more like nature?’s way. You make the pile and leave it to work by itself. This is ideal for very young children and the elderly. The rate of composting depends on the natural conditions in your area. It could take up to a year to make compost.

Trench Composting: This is a good method for those with limited garden space. You can alternate strips of garden between planting beds and compost trench. Add the materials to the trench each day and cover them with a layer of soil. When the trench if filled, leave it until you are ready to rotate garden beds. The old garden bed becomes the new compost trench. The former compost trench is the new garden bed.

Sheet Composting is best used on compacted soils. Compacted soils can be former parking areas or pathways. Instead of making a pile of compost materials, spread over layers of newspaper or thin cardboard. Sprinkle water on the layers as you go. The final layer will be a layer of newspaper or thin cardboard. Put rocks or other heavy objects to keep the paper/cardboard from blowing away. Then soak it with water. Depending on the environmental conditions, in 6-12 months, sheet can restore ?“hard pan?” to soils suitable for planting.

Worm Composting: We try to add local earthworms to all of our compost piles. If you have an abundant supply of manure, making a pit or pile with worms will speed up the ?“aging?” of the manure and making compost. The added advantage of this approach is the compost contains worm eggs. Thus, using the compost spreads the earthworm eggs. Earthworms are free ?“living plows?” for the soil.

Composting Strategies for Labor Reduction
We have seen composting done in big operations using tractors and heavy equipment. That is an expensive way to go. Most rural farmers won?’t be able to match it. Farming is hard labor intensive work already. So we tend to seek strategies that don?’t add more work to farm life.

Composting In-Place: Many farms have some orchards. When we prune our orchard, we make many smaller compost piles of the cuttings between the trees. This saves us time and labor from moving all the materials to a bigger compost pile. And after the compost is made, we don?’t have to haul the compost from the larger pile to where it will be used. By having many smaller piles in the orchard, we only need to spread the compost from each pile in the orchard. Over time, the entire orchard is supplied with compost.

Use Gravity to Reduce Lifting: We have some terraced land on our farm. So it makes good sense to make a compost pile on the outer slope of a terrace. When it is ready to use, we push it over and down onto the terrace below it. This saves a lot of time lifting, loading, and transporting compost to the terraces.

What Does Compost Do for Soil?
We teach farmers very simple no tech/low tech ways to test soil texture, structure, and chemistry. Many farmers find soil testing to be hard and complicated. The magic of composting is that regardless of the soil test results, adding compost will tend to move the soil characteristics from either extreme toward ?“neutral?”. For example: If the soil texture is too coarse, or too fine, adding compost will make it more ?“just right?”. If the soil is too acid or too alkaline, adding compost will make it more neutral. If the soil structure is too loose or too tight, adding compost will make it ?“just right?”. Overall, in the tropics, soils tend to lack organic materials. So adding compost (organic matter) improves the soil. The net result is improved plant growth. For some, this is mistakenly perceived as ?“fertilizing?” the soil. In reality, the overall health of the soil is improved so the chemistry is more balanced making it easier for plants to absorb the soil nutrients.

Many of the synthetic agricultural chemicals (e.g. fertilizers. Herbicides, and pesticides) don?’t make it to the plants at all. They soak into the ground, sometimes contaminating ground water and wells. They run off the surface and get into reservoirs, rivers and streams. So the money spent for these ?“escaping?” chemicals don?’t benefit the farmer and the crops. In some cases, the pollution created has hurt farmers, farm workers, and livestock. The costs for these chemicals goes beyond their initial purchase price. In some instances, the costs spread to future generations, too.

We advocate composting because:
?• It reduces the need to buy synthetic agricultural chemicals. This also helps save on possible medical bills.

?• It recycles nutrients from the farm back to the farm. This helps to sustain the farm.

?• It improves soil by increasing soil moisture retention and ability to resist soil erosion. Added organics enrich the soil and the habit for soil organisms. This leads to better soil structure for plant growth.

?• It helps to build and maintain soil. Soil is a vital farm resource that is necessary for good plant growth. Maintaining and protecting it for future generations assures a sustainable farm.

?• It is environmentally friendly by helping to reduce air and water pollution.

?• It makes effective use of ?“waste?” materials to benefit farmers.


[Note: This was a brief description of COMPOST. For the lessons to be meaningful, they are all adapted to local site conditions prior to training. A typical scenario for off-farm training involves time to pre-view the area for the training (about ?½ to 1 day prior to the training). This lets us tailor the lessons to be as site specific as possible. Relevance is critical to making the lessons useful. Thus, there isn?’t a ?“standard?” lesson booklet as such. Included with the training is the ?“teach back?” model. This encourages the participants to share the knowledge with others, just as we are freely sharing our knowledge with them. Payment for the training consists of covering our costs to get to and from the training site, and room/board for the duration of the training. Although we are not a formal / legal non-profit organization, we conduct ourselves in that manner. We are not doing this to make a profit. This is primarily a ?“give back to the community?” activity.]