Organic Fertilizers: Gardening with Sawdust in Soil

A Study Presented toMrs. Catherine G. Malon

Physics Teacher, Clarin National High SchoolClarin, Misamis Occidental

By:Rigen V. Maalam

Jason Emmanuel V. GomezIV-Gemini Students, Clarin National High School

March 2013

ABSTRACTA substantial amount of sawdust (the main component of particleboard) is readily

available in many forest industries and sawmills as a by-product of cutting, grinding, drilling, sanding, and otherwise pulverizing the wood with a saw or other tools. It may also be the by-product of certain animals, birds and insect, which live in the wood such as woodpecker and carpenter ant. Since this material is composed of fine particles and also due to its flammability, it can present a hazard in health, in sawmills and in the environment. However, there are still other usages of these dust particles which can be more beneficial than you might imagine, and thus, this research has been formulated which talks about the utilization of sawdust in gardening.

INTRODUCTIONBackground of the Study

A major use of sawdust is for particleboard; coarse sawdust may be used for wood pulp. Sawdust has a variety of other practical uses, including serving as mulch (an alternative to clay cat litter) or as a fuel. Until the advent of refrigeration, it was often used in icehouses to keep ice frozen during the summer. It has been used in artistic displays, and as scatter. It is also sometimes used to soak up liquid spills, allowing the spill to be easily collected or swept aside. As such, it was formerly common on barroom floors. It is used to make Cutler's resin. Mixed with water and frozen, it forms pykrete, a slow-melting, much stronger form of ice.

But at sawmills, unless reprocessed into particleboard, burned in a sawdust burner or used to make heat for other milling operations, sawdust may collect in piles and add harmful leachates into local water systems, creating an environmental hazard. This has placed small sawyers and environmental agencies in a deadlock. In addition, airborne sawdust and sawdust accumulations present a number of health and safety hazards. Wood dust becomes a potential health problem when, for example, the wood particles, from processes such as sanding, become airborne and are inhaled. Wood dust is a known human carcinogen. Certain woods and their dust contain toxins that can produce severe allergic reactions. Water-borne bacteria digest organic material in leachate, but use up much of the available oxygen. This high "biological oxygen demand" can suffocate fish and other organisms. There is an equally detrimental effect on beneficial bacteria, so it is not at all advisable to use sawdust within home aquariums, as was once done by hobbyists seeking to save some expense on activated charcoal. Sawdust is also flammable and accumulations provide a ready source of fuel. Airborne sawdust can be ignited by sparks or even heat accumulation and result in explosions.

The decomposition of a tree in a forest is similar to the impact of sawdust, but the difference is of scale. Sawmills may be storing thousands of cubic meters of  wood residues in one place, so the issue becomes one of concentration. And therefore, we need to reduce them in a way that it will serve much use than being idle.

Objectives of the StudyAlthough many outlets are available for the utilization of wood fines, economical disposal of sawdust, shavings, and waste chips remains a problem of growing concern to the wood industry. Hence, this report aims to:

1. Review the hazards brought by the increasing amount of sawdust stored in sawmills and in the wood manufacturing industry.

2. Aware the people that sawdust may also be used as an alternative organic fertilizer in gardening.

Significance of the StudyAbout 75 percent of household waste can be made into excellent fertilizer for flower and vegetable gardens provided that beneficial organic waste is used and it is processed correctly. Composting also offers a lot of benefit: a) Soil conditioner. With compost, you are creating rich humus for lawn and garden. This adds nutrients to your plants and helps retain moisture in the soil. b) Introduces beneficial organisms to the soil. Microscopic organisms in compost help aerate the soil, break down organic material for plant use and ward off plant disease. c) Good for the environment. Composting offers a natural alternative to chemical fertilizers.  d) Reduces landfill waste. Most landfills are quickly filling up; many have already closed down. One-third of landfill waste is made up of compostable materials.

The study is very helpful to the gardeners as well, for they will gain ideas on saving expenses by composting sawdust than in buying inorganic fertilizers to grow their plants, moreover, it promotes environmental conservation for the materials used are recycled and very much available in town.

Scope and LimitationsThe research work is largely anchored on the discussion of processing sawdust to be used an

organic fertilizer in gardening. Other uses of sawdust are also mentioned, however, the study is only focused on sawdust, not including the bark, wood chips and other parts of the tree which are also by-products during the process of manufacturing woods.

RESEARCH METHODOLOGYMaterialsDedicated gardeners love to compost and they will compost everything possible. All plant matter can be composted most especially the sawdust except for the roots of perennial weeds, which are not killed by the home composting process. Wood and bark are not added to the compost heap as they take many years to rot down, but sawdust can be composted. It requires some preparation and must come only from unpainted and untreated wood.  However, nitrogen loss can occur, so additional fertilization may be required.

State of ProcedureIf you have heavy clay or sandy soil in the garden, it is a common practice to incorporate organic matter into it to improve moisture retention and to loosen up the texture. If organic matter is not incorporated, your plants will not thrive there; they may even die in heavy clay. One type of organic matter that can be mixed into the soil is sawdust.

Instructions: Spread a 3-inch to 4-inch layer of aged sawdust over the desired planting site and smooth

it out evenly using a bow rake. Pour and spread a 1-inch to 2-inch layer of coarse sand on top of the sawdust and smooth

it out with the bow rake as well. Position your garden tiller at the edge of the planting area and set the blade depth on it to

between 8 and 10 inches. Start the tiller and push it slowly and steadily over the entire area to mix the sawdust and

sand into the top layer of soil. Spread a granular fertilizer over the area to help the sawdust break down faster. Apply the

fertilizer at a rate of 2 lbs. for every 100 square feet of space. Ohio State University suggests using a fertilizer with numbers of 5-10-5, 8-8-8 or 12-12-12 for the best results.

Plant any desired plants according to the specifications on the plant labels. Watch the leaves carefully throughout the growing season to ensure they do not turn yellow, which sometimes occurs when sawdust is added to the soil. If yellowing occurs, apply a separate granular fertilizer that is high in nitrogen.

Statistical ToolsBow rake and tiller are used in the process to smooth the mixture of sawdust and soil

evenly. If the mixture is not well mixed, it may take more time before the wastes decompose.

RESULTS AND DISCUSSIONThe illustration below shows the schematic diagram of the research work.

Dependent Variable Independent Variable

If fresh sawdust is put onto the compost heap or directly onto the soil, it leaches nitrogen from the soil and the plants. Sawdust is very high in carbon and the bacteria which digest it require nitrogen to do so. If sawdust is added to the compost heap, extra nitrogen must also be added in the form of animal manures. Manure from poultry and any herbivore can be added to the heap, manure from humans, pigs, cats and dogs should be avoided as it contains parasites which survive the composting process.Warning

Dr. Charles Xu's research confirms that wood contains chemicals such as phenol (carbolic acid). It is best to remove these before adding sawdust to the compost heap. Make a heap with the sawdust and leave it for at least four weeks, preferably up to a year, watering regularly and turning each week. The phenols will leech out of the sawdust making it safer to compost. Alternatively, use sawdust for garden paths to suppress weeds. After a year, simply add it to the compost heap or dig it into the soil with plenty of nitrogen rich manure.

The perfect compost heap contains equal quantities of nitrogen and carbon rich materials, often called "greens and browns." Nitrogen rich ingredients are the "greens" from grass cuttings, annual weeds and the green growth of perennial weeds, but not the roots. Some gardeners grow comfrey specifically to add to their compost heap and peelings from the kitchen, tea bags and coffee grounds can be added as can crushed egg shells. Manures from poultry and herbivores are nitrogen rich and human urine diluted 20:1 speeds up the composting process, especially useful if sawdust is added to the heap.

Sawdust is a valuable addition to the compost heap. The ideal heap is made from alternating layers carbon and nitrogen-rich materials. Add a layer of greens and follow with a layer of browns and add some manure. Pelleted chicken manure is absolutely fine if you don't want a small mountain of horse manure in your yard. Keep the heap moist but not wet, and turn or aerate it occasionally, and the result should be a rich, dark earthy material full of nutrients for your plants.

CONCLUSIONFindings

SAWDUST ORGANIC FERTILIZER FOR GARDENING

The result shows that sawdust can also be used as an organic fertilizer. You can do gardening with fresh or composted sawdust. It does not only help you grow your plants, but it will also help in the conservation of our environment. You can also save expenses by doing your own fertilizer; however, you will need enough amount of fertilizer during the composting to help the mixture decompose faster.

RecommendationThe researchers highly recommend the following to be check when composting with sawdust:

If you are placing the sawdust in soil where you grow edible plants, vegetables or fruits, make sure it is not from lumber that has been treated with chemicals.

To avoid excessive nitrogen loss caused by adding sawdust, use only well-aged sawdust, not fresh.

Garden tillers are available for rent at home improvement centers, if you do not already own one.

Ensure that the sawdust is fine and does not contain wood shavings, since these decompose slowly.

BIBLIOGRAPHY

http://www.ehow.com/HowtoGardenWithSawdustintheSoil.htm

http://Eartheasy.com/Compostingaguidetomakingcompostathmeusingcomposttumblersbins&othercomposters.htm

http://ehow.com/CompostingSawdusting

http://Wikipediaencyclopedia/Sawdust.htm