Feasibility of Developing the Organic and Transitional Farm Market - Assignment Example

INTRODUCTION The increasing global waste production is a major problem faced by most countries today. Plastics, papers, scrapped metals, and food wastes are some of the many waste products produced by most people. The increasing demands of people and countries to technology in health, research, agriculture, electronics, constructions, and other industries leads to the increase production of waste from these industries. The fast rate of population increase worldwide also contributes to rapidly increasing waste production. In the industrialized countries such as the United States of America, United Kingdom, France, Germany, Japan, Australia, and Russia, successful management of waste is one of the many issues they are facing in the future. Most of these countries already started the recycling of their garbage. Many recycling plant were built for plastics, metals, and biodegradable waste but dumping of waste on landfills is still being practiced. The rate of recycling of biodegradable waste was the major difficulty for most of the landfills. The faster rate of waste input as compared to the waste degradation to the landfill pushed many governments to look for an alternative and faster way of decomposing organic waste products (Recycled Organics Unit 9). Decomposting is a process by which organic waste matter is buried or stood still to allow bacterial decomposition to occur. Bacterial decomposition of organic waste is naturally occurring in garbage landfill but the rate of it is slow. Other methods were used to allow faster decomposition of organic waste in garbage landfill. Using worms to increase the rate of conversion from organic waste to fine organic materials is known as vermicomposting (Munroe 1). The result of decomposting is the "compost" production. Compost is a fine, nutrient-enriched, soil-like materials from the decomposed organic waste. Composts are used as an organic fertilizer by farmers. The use of worms in decomposting, which is known as vermicomposting, would produce a vermicompost. Vermicompost is like compost and both are used as an organic fertilizer. Since the rate of production of vermicompost is faster than the compost, the use of vermicomposting in organic fertilizer production and organic waste management recycling is favored (Recycled Organics Unit 9). The increasing popularity of vermicomposting on both waste management and fertilizer production leads to the increasing demand of worms. The worm, specifically earthworms, culture is called vermiculture. Vermiculture is a process by which earthworms are nurtured and fed in a bin or other storage materials to increase their numbers. The number and reproduction rate of the worms should be enough to sustain a regular harvest (Munroe 1). Although vermicomposting uses earthworm, there are only some species of earthworm that could be used and readily available for vermiculture. There are three types of earthworm namely epigeic, endogeic, and anecic type. Epigeic type of earthworm thrives on the surface of the ground. This type of earthworm feeds on fine or decaying organic matter readily available on the ground. On the other hand, endogeic type of earthworm thrives in the ground. This type of earthworm makes and lives in a horizontal hole within the ground. Endogeic earthworm surfaces very seldomly because it already feeds on organic matter imparted within soil. Anecic type of earthworm makes and lives in vertical hole within the ground. The vertical burrow serves as their protection and passage to the surface of the ground to obtain food at night (Recycled Organics Unit 13). Epigeic type of earthworm is used mainly in vermicomposting but anecic type could also be used in addition to the epigeic. Although there many species of epigeic earthworm that can be found in decomposting and vermicomposting area, Eisenia fetida is the most commonly used species in vermicomposting particularly in temperate countries because the rate of organic matter utilization and reproduction is fast, the range of tolerance to chemical and physical parameters of environmental is high, and the manageability of this species is easy (Munroe 1; Recycled Organics Unit 14). The same reasons as mentioned above why Eisenia fetida is also widely propagated in vermiculture. Vermiculture of Eisenia fetida is an emerging industry today due to the demand from vermicomposting industry for waste management and organic fertilizer production. Success in raising and reproducing this earthworm species is easily attainable but the faster rate to attain this success is dependent to the food conversion ratio to the density and body mass of the species. The food conversion ratio of Eisenia fetida is dependent to its food consumption rate. Although the type of organic food matter being fed to Eisenia fetida is not important in vermicompost, in vermiculture, it is essential to know what kind of food is being preferred by the species and how this particular food would affect the weight increase or growth of it. The general objective of the study is to define the food preference of Eisenia fetida. It specifically aims to: 1. Identify and compare the consumption rate of Eisenia fetida with rice, bread, fruits- banana, watermelon and pear- and vegetables- spinach and cabbage-, and; 2. Discuss the effect of food consumption rate to weight increase or growth. REVIEW OF LITERATURE Vermiculture Worm farming or vermiculture is the process where the primary objective is to increase the population of specific species of worm to support a regular harvest for commercial purposes or for increase in worm stocks to expand vermiculture operation (Munroe 1). Since the use of organic waste products as food for worms is involve, not only the worms produced in the farm are source of income but the produce vermicompost as well (ROU 17). According to Glenn Munroe, there are five important things needed for successful worm farming. Firstly, a suitable environment for the worm is needed for bedding. Secondly, a sustainable and cheap food source should be available. Thirdly, the compartment where the worms are bedded has adequate moisture. Fourthly, an excellent air circulation system is present. And fifthly, the place for vermiculture operation is protected from extreme environmental conditions such as temperature (5). A suitable habitat is provided for the worms to successfully survive and eventually reproduce. If the environment of worms is within the range of their optimum requirements, their growth and reproductive efficiency will increase, resulting to more production at shorter time. The compartment or bin where the worms are being propagated should have excellent "beddings". The "beddings" could be any materials but some characteristics are important. It should have high absorbency to maintain a moist environment for the worms (Munroe 5). Moisture content of "beddings" should not be less than 50% (Munroe 10). As cited by Glenn Munroe, Dominguez and Edwards stated that the range for moisture requirement of Eisenia sp. was from 80% to 90% while Rink et al. suggested a range of 45-60% moisture content (10). Since worm's respiratory organ is their skin, maintaining a moist skin means breathing easily. Also, "beddings" should be a material which is low in nitrogen or protein content so that its degradation process, if not avoided, is slowed. Furthermore, the beddings' layering should have the right density so that air could flow throughout the bin to avoid suffocation (Munroe 5). Food consumption of worms is high. According to Glenn Munroe as mentioned in the study of Gaddie and Douglas, food of worms is restricted to organic matters. Some foods are being preferred, although, worms can consume everything that is organic. Beef and dairy manure are well known desirable food for Eisenia sp., though, any manure could be used. The natural food consumption of worms in the environment is more than their body weight everyday, but in vermiculture, the normal amount of feeding input practice is of their body mass. Meat- and fat-based wastes present in the feeding material of worms, when decomposed by bacteria, produced ammonia and other harmful chemical substances. Pre-composting these kinds of wastes before feeding to the worms is essential to maintain optimum habitat condition (Munroe 10). Composting worms, specifically Eisenia sp., could tolerate wide range of temperature. Although they can survive for as low as 0 degree Celsius, their reproduction and food consumption is impeded. In vermiculture, 15 degrees Celsius is the optimum temperature while 20 degrees Celsius is needed for good vermiculture production. Death occurrences are commonly observed when temperature is more than 35 degrees Celsius while temperature above 20 degrees Celsius triggers breeding (Munroe 11). Other abiotic conditions affect the survival of the worm. Worms preferred pH that is within the range of 7.5 to 8.0 (GEORGE no page). Moreover, only less than 0.5% of salt is favored by worms. Washing by running water could remove the salt content of the feeding materials if this is a marine origin such as seaweeds, as well as, it can remove the urine content if this is an animal origin. Eisenia fetida The earthworm Eisenia fetida is an epigeic type of worm. It is most commonly used vermicompost worm in temperate countries. Eisenia fetida is commonly known as compost worm, tiger worm, or wriggler worm. Like any other earthworm, Eisenia fetida can increase the decomposition rate of organic matter significantly. With the food rich in cellulose, Eisenia fetida can quickly increase their body mass. They are opportunistic animals that when favorable conditions of environment are present, they can rapidly grow and reproduce to successfully maintain their population. This adaptation could ensure their survival when unfavorable conditions happened. In the study of Zachmann and Molina, Eisenia fetida has been used as a bio-indicator of stabilization of organic matter and xenobiotic compounds spread to environment (1904). The efficiency and rapid conversion of organic matter to humus by earthworms, specifically Eisenia fetida made the vermiculture industry a success. Although any organic matter could be eaten by Eisenia fetida, the study of Suthar suggested that the food type is still important and the major factor influencing the growth rate of the worm (79). Specifically, the nitrogen content or carbon-nitrogen ratio is the major factor that dictates the behavior and activity of worms. METHODOLOGY Nine plastic containers were initially prepared. Six containers have been used for the experimental observation and data collection of the food consumption rate of Eisenia fetida while the remaining three containers were used for the experimental observation of the food preference of Eisenia fetida. The area of each six containers used for the food consumption rate experimental set-up was 100 square centimeters (cm2) while the size of the remaining three containers used for the food preference experimental set-up was 15 centimeters (cm) by 30 centimeters (cm). Paper cartons were used for the beddings for all containers. Eighteen paper cartons were cut by 10 cm by 10 cm while (3) three paper cartons were cut by 15 cm by 30 cm size. Six 10 cm by 10 cm cartons and three 15 cm by 30 cm cartons were soaked to water before they were used as beddings for the 9 containers. The remaining twelve 10 cm by 10 cm cartons have been used later in the experiment. Furthermore, 6 types of food were used in the experiment. The foods were steamed rice, plain bread, ripened banana and watermelon, and steamed spinach and cabbage. Each food types were chopped into fine pieces to have a uniform particle size. Food consumption rate (FCR) was computed using the formula: FCR = Weight Change of Food (g) / Time Duration (hrs) In the food consumption rate experiment, three batches of set-up, each batch were tested two kinds of food with three replicates for each, were conducted. The six 10 cm by 10 cm container with wet carton served as a beddings were used for this set-up. The first batch of foods tested was steamed rice and plain bread. The second batch of foods tested was ripened banana and watermelon while the last batch of foods was steamed spinach and cabbage. In the first batch, 50 grams (g) of steamed rice were put in three containers labeled A1, A2, and A3, while, 50 g of plain bread were put on the other three containers labeled B1, B2, and B3. The whole surface area of the containers was covered by the food to obtain the same area. The same procedure had been used for all the three batches of set-up. Eisenia fetida were obtained to be use in the experiment. The worms were allowed to stand for 12 hours (hrs) at 15 degrees Celsius (oC) without any food before they were used in the experiment. This was done to minimize the gut content for each worm to maintain the same food appetite of the worms for all batches. Container A1, A2, A3, B1, B2, and B3 were put each with pre-weighed six worms. Upon the addition of the pre-weighed worms, the time was noted. The range of temperature between 23 oC to 25 oC was maintained. After 48 hrs, the remaining food in the containers has been weighed. The weigh of all six worms from each container was also recorded. The six containers used were all cleaned after the data collection. Beddings were replaced. The experiment was repeated using the other four remaining food types. Food preference experiment was done using the three 15 cm by 30 cm containers. After the beddings were placed, each pre-weighed (10 g) food types were put in the containers. The foods were arranged in a "stripe" manner, parallel to the 30 cm side of the container. The size of each food stripes was 2 cm by 4 cm, making six stripes in each container. The containers were labeled L, C, and R. The food stripes were arranged from (left) steamed rice, plain bread, ripened banana, ripened watermelon, steamed spinach, and steamed cabbage (right) for all 3 containers. The same worm species (Eisenia fetida) was used in the food preference experiment. The worms were allowed to stand for 12 hrs at 15 oC temperature without any food. Ten pre-weighed worms have been put in each container. In container L, the worms were put at the left side, 5 cm away from the food stripes. Moreover, worms were put at the right side in container R, while in container C; the worms were put at the center, both R and C were 5 cm away from the food stripes made. Temperature of the containers was maintained within the range of 23 oC to 25 oC. Observations were made every 6 hrs for 60 hrs. The remaining foods from each type were weighed separately after 60 hrs duration for each container. The data collected were then analyzed. RESULTS The initial weight of each food type for the food consumption experiment was 50 grams. After 48 hrs, the weight of food was measured. The food consumption rates for all six food type with 3 replicates each were computed by dividing the measured weight change of food by 48 hours. The food consumption rates were then listed in Table 1 (see Appendix 1). The final weight of worms for all food type of each replicates was also measured. The initial weights of worms were then subtracted by the corresponding final weights to get the value of the weight changes. The data were then listed in Table 2. (see Appendix 1). The average food consumption rate for three replicates was computed and used for comparison to different food type consumption preference. Ten observations were made for each replicate L, R, and C container. The number of worms present above each food type was noted every 6 hrs for 60 hrs. Initial and final weights of food types were also measured and recorded. The food weight change was calculated by subtracting the initial weight to the final weight measured for each food type. Weight change data were used as the basis for food preference of worms in addition to visual data observation. The visual observations for the food preference of the three replicate L,C, and R, and the weight change for each food type were listed in Table 4, 5, 6 and 3, respectively (see Appendix 1). Six observations were made every 6 hours. The number of worms present to specific food stripe was counted. Some worms were observed to be located at the center of two food stripes. The clitellum of the worm located between the two food stripes was identified to successfully locate the mouth part. The food stripe where the mouth part is located was the area identified for the location of the worm. DISCUSSION The food consumption rate of the three replicates for each food type were averaged and compared. The result showed that the Eisenia fetida fed with ripened banana had the fastest food consumption rate of 0.1661 g / hr while the slowest food consumption rate (0.0594 g / hr) was when plain bread was the feedstock. Following the ripened banana was the ripened watermelon with 0.1507 g / hr, steamed spinach with 0.1482 g / hr, steamed cabbage with 0.0910 g / hr, and steamed rice with 0.0638 g / hr. The food consumption rate of both fruits was almost the same as compared to other data. Although the food consumption rate from steamed spinach is close to the data for ripened watermelon, if the weight of the worms used on both replicates were compared, the worm weight used in steamed spinach was greater by 0.1433 g. Since the weight of worms is proportional to the amount of their food consumption, then the assumption that the close difference between the two data is mainly due to weight difference. Therefore, it can be concluded that fruits were being consumed more rapidly than the other food. Also, since fruits are moist in nature and rich in vitamins, minerals and sugars necessary for easier microbial growth and worm ingestions, then it is natural to consume fruits faster than any other food type. Furthermore, if spinach and cabbage which are both vegetables were compared to the consumption rate of fruits, the low in sugar and rich in fibers of vegetables makes it more difficult to be consumed. On the other hand, steamed rice is easy to act upon by microbial decomposers. Although the consistency of rice makes it easier for worms to ingest, the production of lactic acid by the microbial decomposers and its rate of production are very fast that the pH of its surrounding environment is greatly affected. The lowering of pH due to this substance can inhibit the activities of worms as well as its food consumption. Plain bread's consistency makes it also easy to ingest by the worms but the absence of microbial decomposition in the bread, and the dry texture of bread hindered the worm's consumption. Moreover, the presence of preservatives in the bread might have been the primary reason for slow microbial degradation as well as the lack of moisture. The accumulative weight gain of worms used to measure the food consumption rate was also measured for each replicate. The highest weight gainer was the worms fed with banana- 0.150 g increase- while the lowest gain was when bread (0.025 g) was fed. The weight gain data were directly correlated with the food consumption rate. The data suggested that the worm recorded to have the fastest food consumption rate were to have the highest weight gain. The assumption is true to all replicates of the experiment. Since the amount of supply of nutrients necessary for growth and development is directly affected by food intake, then, it is only natural for weight gain to be dependent to food consumption rate. Furthermore, the data collected from the three replicates of food preference experiments were obtained. The number of worms present on each food type was counted and the remaining amount of each food type was weighed. Based on the data obtained, the amount of ripened banana (10 g) was all consumed by the worms for the entire 60 hrs duration. The next highest average amount consumed was the ripened watermelon with 6.77 g, next is steamed spinach with 2.71 g consumed, followed by the steamed cabbage with 1.63 g, then steamed rice with 0.76 g, and lastly the plain bread with no consumption at all. The result showed that Eisenia fetida preferred mostly the banana as food as compared to other food type used. The assumption was suggested by the weight consumed. Moreover, to further support the preferred food assumption of the worms, observations were made to count the number of worms present on top of the food for every 6 hours. The data observed also supported the first assumption that the most preferred food was banana, next is the watermelon, then spinach, followed by the cabbage, then rice and lastly bread. For the first 18 hours, most of the worms were observed to be on top of the banana. The amount of worms decreased after 24 hours until the complete consumption of the banana. With the start of the 24th hour observation, the worms slowly migrated to the watermelon. As early as 36th hour observation, some of the worms already migrated to the cabbage while few worms remained on the banana. At the 40th hour observation, no trace of banana remained while most of the worms migrated to the watermelon and started to invade the cabbage. In the three replicates, almost the same observations were obtained. Most of the worms were at the right side of the containers while few worms migrated to the rice as early as 36th hour observation as but not later than 42nd hour observation. The number and behavior of worms observed and the weight of the food remained supported the concluded food preference of the worm. The food consumption rate, the rate of weight increase, and the preferred food were also directly correlated as shown in figures 1 and 2. It can be concluded that the amount of feedstock given to worms is not the key factor for their weight gain but the kind of food present in the feedstock. Furthermore, the data gathered from the experiment suggested that the fruits were preferred more by Eisenia fetida, followed by vegetables, then grain products. Figure 1. The food consumption rate and weight gained by Eisenia fetida. Figure 2. The food preference of Eisenia fetida as suggested by the amount of food consumed. The study of Suthar suggested that the Carbon-Nitrogen ratio of food given to the worms played a vital role in growth and weight gain. The study suggested the importance of food composition not the amount for optimization of growth rate (79). The observations obtained in the experiment where worms preferred a specific food over the others could be related to the nutrient composition of food, although the food compositions were not identified in this experiment. Furthermore, detailed food analysis, longer time and higher density of worms could be done for future experiments. References Gaddie, R.E. Sr. and Donald E. Douglas. "Earthworms for Ecology and Profit. Volume 1: Scientific Earthworm Farming." Bookworm Publishing Company: 1975 180 pp. GEORG. "Feasibility of Developing the Organic and Transitional Farm Market for Processing Municipal and Farm Organic Wastes Using Large-Scale Vermicomposting." Good Earth Organic Resources Group, Halifax, Nova Scotia. 2004: 1. Munroe, Glenn. "Manual of On-Farm Vermicomposting and Vermiculture." Organic Agriculture Centre of Canada 1-56. Recycled Organics Unit. Literature Review of Worms in Waste Management 1 Sydney, Australia, 2007: 1-52. Rink, Robert. "On-Farm Composting Handbook." Natural Resource, Agriculture, and Engineering Service (NRAES-54) 1992: 90 Suthar, S. "Influence of Different Food Sources on Growth and Reproduction Performance of Composting Epigeics: Eudrilus eugenlae, Perionyx excavatus and Perionyx sansibaricus" Applied Ecology and Environmental Research 5 May 2007: 79-92. Zachmann, Joseph E. and J.A.E. Molina. "Presence of Culturable Bacteria in Cocoons of the Earthworm Eisenia fetida." Applied and Environmental Microbiology 59 June 1993: 1904-1910. APPENDIX 1 Table 1. The weight (g) change of steamed rice, plain bread, ripened banana and watermelon, and steamed spinach and cabbage, and food consumption rate (g/hrs) after 36 hrs. SR-steamed rice; PB-plain bread; RB-ripened banana; RW-ripened watermelon; SS-steamed spinach; SC-steamed cabbage Table 2. The weight gain of Eisenia fetida in grams for 48 hours with different food types. SR-steamed rice; PB-plain bread; RB-ripened banana; RW-ripened watermelon; SS-steamed spinach; SC-steamed cabbage Table 3. The weight (g) change of steamed rice (SR), plain bread (PB), ripened banana (RB) and watermelon (RW), and steamed spinach (SS) and cabbage (SC) arranged in stripes after 60 hours of exposure to Eisenia fetida. Table 4. The number of Eisenia fetida found on each type of food for every 6 hours for 60 hours in replicate L. Table 5. The number of Eisenia fetida found on each type of food for every 6 hours for 60 hours in replicate C. Table 6. The number of Eisenia fetida found on each type of food for every 6 hours for 60 hours in replicate R. Read More