Utilization of Biodegradable Kitchen Wastes Into Organic Fertilzer Using Earthworms (Lumbricus Terrestris
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Submitted By jacksoncasibang Words 1216 Pages 5
ABSTRACT
One of the effective means to at least lessen the occurence of our present garbage disposal problem is through the use of methods that are non-toxic, less expensive, less-harmful, and yet equally effective. This project aims to provide for a natural and effective way of disposing garbage.
During the experiment, kitchen wastes were collected. The materials were shredded and placed in garbage bags with small holes. The temperature inside the bags was allowed to lower.
Three set-ups were prepared and were covered with plastic. The first box contained pure carabao manurd, the second box contained 70 percent carabao manure and 30 percent processed kitchen wastes and the third box contained pure processed kitchen waste. Lumbricus terrestris was placed in each set-up. The boxes were placed in a lighted area while maintaining their moisture. After drying, the Lumbricus terrestris were gathered. The resultant product, called "earthworm castings," were then sun-dried and passed through a fine sieve to remove foreign materials.
Results showed that the casting from kitchen wastes and manure was highest in percentage total nitrogen, third highest in percentage total P205, and highest in percentage total K20.
It was concluded that organic kitchen wastes can be converted into a competitive organic fertilizer using Lumbricus terrestris. The organic fertilizer produced by using earthworms can compete in terms of nutrient contents with other organic fertilizers.
INTRODUCTION
A good alternative in solving our garbage problem is vermicomposting, the process in which organic wastes are decomposed naturally with the use of earthworms.
This research focuses on the efficient decomposition of organic kitchen wastes using Lumbricus terrestris and converting these wastes into organic fertilizer that can compete in terms of nutrient content with other organic fertilizers.
This study provides additional research material in using earthworms as agents for decomposition of organic wastes. It aims to provide better and simpler means of waste disposal while producing something useful -- organic fertilizer.
This research only tested the macronutrient contents of the harvested earthworm castings and compared them with those of other organic fertilizers. This study, however, did not include tests for micronutrient contents and, other qualities of the castings produced. Also this-stUdy did not test whether different waste materials produce different nutrient content for the castings.
REVIEW OF RELATED LITERATURE
Vermicomposting'is the culture of earthworms in a composting system. The earthworms ingest organit matter as well as soil. As these materials pass through the earthworm's body, they are mixed with digestive enzymes and reduced by the grinding action within the animal. The organic matter comes out Of the earthworms as castings which contain plant nutrients. To work well, the earthworms prefer a well-aerated bkrt moist habitat, They thrive well where farm manure or plant _residues had been added to the soil. Most of them thrive best where the soil is not too acidic. (Brandy, 1990).
Apelhof, as cited by Blackgold Vermicompost Manufacturing Corporation (BVMC, 1987), reported that the Lumbricus terrestris, one of the 3000 species of earthworm presently identified, caught the interest of agriculturists and other earthworm enthusiasts. The Lumbricus terrestris or African night crawler has a deep maroon shade, and measures from 4 to 12 inches in length.
Composting produces essential nutrients for plant growth. These nutrients are classified into macro and micronutrients: Relatively large amounts of macronutrients are required whereas micronutrients are required in small amounts only. These elements must be present in right proportions for when there is deficiency or excess of any one element, this may seriously affect plant growth. The plants would develop symptoms of starvation or toxicity. The macronutrients include nitrogen, phosphorus and potassium. Every living cell contains nitrogen and its abundance leads to green, succulent growth.
Phosporous occurs in the protoplasm, with its great concentration in seeds thereby increasing -their production. Potassium influences the uptake of other elements and affects both respiration and transpiration (Fitzpatrick, 1974).
METHODOLOGY
Kitchen wastes, composed mainly of vegetable and fruit peelings, were gathered, shredded, and placed in garbage bags with small holes. Temperature build-up inside the bags due to partial decomposition was measured and allowed to lower down for one month until three consecutive declining of temperature were achieved.
Three set-ups measuring 15 x 8 inches were prepared and were covered with plastic. One box contained pure carabao manure, the other box contained 70 percent carabao manure and 30 percent processed kitchen wastes and the last box contained pure processed kitchen waste. About one hundred pieces of Lumbricus terrestris were placed in each set-up. The boxes were placed in a lighted area to prevent the worms from escaping Since worms are known to be light-sensitive. The set-ups were checked daily and watered to keep moisture. Upon consumption of the contents of the boxes, as evidenced by the appearance of brown granular structures, the set-ups were spread on newspapers under the sunlight. The Lumbricus terrestris were gathered. The resultant product, called "earthworm castings," were then sun-dried and passed through a fine sieve to remove foreign materials.
A laboratory analysis on the macrocontent of the earthworm castings was conducted by the Soils Department of the Sugar Regulatory Administration, La Carlota City. The nutrient contents were then compared with those of other organic fertilizers.
RESULTS AND DISCUSSION
During the production of earthworm castings, the Lumbricus terrestris placed in the box, which contained pure processed kitchen waste were found dead after one day. The death of the earthworms can be attributed to the acidity of the kitchen wastes. As organic matter decomposes, inorganic and organic acids are formed.
Carbonic acid, sulfuric acid, and nitric acid are some of the acids formed by the organic decaying process. High concentrations of these acids may have caused the deaths of the earthworms in the set-up using pure kitchen waste.
Both the castings harvested from the set-up which contained pure manure and from the set-up which contained mixture of manure and kitchen wastes were tested for their Nitrogen-Phosphorus-Potassium micronutrient value. The results were compared with those of other available fertilizers. See table.
Results showed that the castings from kitchen wastes and manure ranked first in percentage total nitrogen and K20 and ranked third in percentage total P205. But this does not mean that the castings produced would be very efficient in promoting plant growth because nutrient content of most organic fertilizers are usually in slow availability form when added in the soil. Nitrogen is held by soil colloids. 'Phosphorous compounds are mostly unavailable for plant uptake, some being insoluble. When soluble phosphorus is added in the soil, they are quickly fixed into insoluble forms that in time become quite unavailable for plant absorption.
Fortunately over time, potassium can be released to exchangeable form that can be quickly absorbed by plant roots.
SUMMARY AND CONCLUSIONS
Earthworm castings from kitchen wastes mixed with manure can compete with other organic fertilizers. Organic kitchen wastes can therefore be converted into competitive organic fertilizer using Lumbricus terrestris.
RECOMMENDATIONS
The study made use of only one specie of earthworm — Lumbricus terrestris. Other untested species may produce significant results. Also, the use of specific kitchen wastes or other organic trash as earthworm feed is recommended. This may have an effect on the chemical and physical composition of the castings and their use as an organic fertilizer.