Earthworms and Microbes in Environmental Management Through Vermitechnology-Mediated Organic Farming
ABDULLAH ADIL ANSARI
Department of Biology, University of Guyana, Georgetown, Guyana
Earth has a number of plants that have been providing food, promoting health, and some form of shelter towards civilization thr oughout the years. The soil is considered to be a major component of plant growth that helps to provide homes for many organisms (Ismail, 2005). Soil microbiology influences the above-ground ecosystem by contributing to plant nutrition, plant health, and soil structure, and soil fertility. However, they also play a pivotal role in various biogeochemical cycles and cycling organic compounds (Kirk et al., 2004). Plant growth is improved when beneficial microbes that increase nutrient availability, also stimulates plant growth without actually increasing nutrient availability to plants (Ismail, 2005). Microorganisms are tiny one-celled organisms found in the micro-biotic layer of the soil, responsible for building fertile soil for plant growth.
Bio-fertilizers, referred to as the use of soil microorganisms to increase the availability and uptake of mineral nutrients for the plant (Ismail, 2005), they are a substance that is added to the soil to enhance the microorganisms, in order to increase the nutrient status. Various Composting techniques are used for the production of biofertilizers vermicompost, biodung, tank compost, and microbe enhancers-Biodynamic preparation 500.
Vermicompost helps to promote humidification, increases microbial activity, and enhances enzyme production. It also facilitates the soil aggr egation resulting in better aeration when applied to the soil. It is prepared through the application of earthworms. It has excellent structure, porosity, aeration drainage, and moisture-holding capacity, and helps to improve the physical, chemical, and biological properties of the soil (Ansari, 2008). Biodung compost and tank compost is similar to that of Vermicompost, except that earthworms, is used in the degradation of organic materials, and cow dung slur is used to aid in the degradation of organic waste in the tank and biodung compost. Biodynamic preparation 500, also known as cow horn manure, is fermented cow dung, which upon application aid in the fertility of soil. This technique helps to enhance and improve the structure of the soil quickly and effectively. Cow horns with the cow dung buried in the soil produce humus, which is to be beneficial to soil (Proctor, 2006).
Excessive use of chemical fertilizers and pesticides in agricultural lands over a long period of time has resulted in poor soil health with a combined effect on crop production and increase incidences of pests and diseases. These concerns have led to a greater economic impact on fanners. Over the last few years, the problems associated with food security has led to thinking in terms of organic agriculture by soil management techniques and microbial innovations. Soil microbiology influences the above-ground ecosystem by contributing to plant nutrition, health, soil structure, and fertility. They also play a pivotal role in various biogeochemical cycles and cycling of organic compounds (Kirk et al., 2004). Plant growth is unproved when beneficial microbes increase nutrient availability and stimulate plant growth (Ismail, 2005). Biofertilizers referred to the use of soil microorganisms to increase the availability and uptake of mineral nutrients for the plant (Ansari, 2008); they are substances added to the soil to enhance the microorganisms, in order to increase the nutrient status. Vermicompost is one of the biofertilizers that helps to promote humification, increased microbial activity, and enzyme production, which subsequently helps to increase the aggregate stability of soil particles resulting in better aeration wrhen applied to the soil. The material has excellent structure, porosity, aeration drainage, and moisture-holding capacity, and helps to improve the physical, chemical, and biological properties of the soil (Ansari, 2008).
The biocomposting method is made up of two phases (breakdown and buildup phase), hi the breakdown phase, biodegradable wastes are decomposed into smaller particles. Proteins are broken down into ammo acids and finally to ammonia, nitrates, and free nitrogen. Similarly, urea, luic acids, and other non-protein nitrogen-containing compounds are reduced to form different plant nutrients. In the build-up phase, there is the re-synthesis of simple compounds into complex humic substances. The organisms responsible for transformation to humus are aerobic and facultative aerobic, sporing, and non-sporing and nitrogen-fixing bacteria of the Azotobacter and Nitrosomonas group. Actinomycetes also play an important role. There are two major reasons why vennicomposting is better. Waste is converted faster, and conventional composting takes weeks to months to convert organic matter to compost, which are very labor-intensive. By using earthworms, waste is rapidly filmed into vennicompost. The vermicompost is far superior to conventional compost. The worm castings in the vennicompost have nutrients that are highly utilizable by plants, and the castings have a mucous coating that allows the nutrients to “time-release.” Vennicompost fonns fine stable granular organic matter that assists in the aeration, released mucus that are hygroscopic absorbs water and prevents waterlogging, and improves water-holding capacity. Vennicompost added to the soil releases nutrients slowly and consistently and enables the plant to absorb these nutrients more readily. Soils enriched with vennicompost provide additional substances that are not found in the chemicals (Kale, 1998; Ansari and Ismail, 2001). Biofertilizers contribute both macro and micronutrients in amounts that are required by the plant and upon application have an emphatic effect on plant gr owth parameters and production.
Vennicomposting is the biological degradation and stabilization of organic waste by earthworms and microorganisms to form vennicompost. This is an essential part in organic fanning today. It can be easily prepared, has excellent properties, and is harmless to plants. The earthworms fragment the organic waste substrates, stimulate microbial activity greatly, and increase rates of mineralization, they release a coelonric fluid that has antibacterial properties and destroys all pathogens in the media in which it inhibits. These rapidly convert the waste into humus-like substances with finer structure than thermophilic composts but possessing a greater and more diverse microbial activity (Ansari, 2008). The material has excellent structure, porosity, aeration, drainage, and moisture-holding capacity, and helps to improve the physical, chemical, and biological properties of soil (Ansari, 2008).
Biodynamic agriculture is a system of organic agriculture that has proved to be very effective throughout the world. The results are better soils, better quality food, healthy plants, healthy, and contented animals, and enthusiastic fanners and consumers. Cow horns and cow dung is used to produce this fertilizer, and after being buried together in the earth, make the most wonderful hummus to spread on the land. This help to improve the structure of the soil dramatically and quickly. Good soil structure means better water-holding capacity, which means better control, with consequently less loss of topsoil, which means better and deeper roots and less need for irrigation, which means deeper soil and more natural fertility (Proctor, 2006).
Biodynamic agriculture falls into the categoiy of general organic agriculture, the main differences being in the use of biodynamic preparations for soil (preparation 500), plants (preparation 501), and compost (preparations 502-507). The agronomic system is based on a universal approach of the whole farm, and under this aspect, the simple use of preparations could not completely be defined as a biodynamic approach. However, from a scientific point of view, the only way to compare results from different fanning systems is to study the effect of preparations. Even if some efforts have been made to explain the mechanism by which these preparations act, their effect on plant physiology, soil microbiology, and compost characteristics is still not explained. Only a few papers compare the results obtained with biodynamic agriculture with those from conventional fanning (Heirnler et al., 2012). Marry organic practices are scientifically testable and can result in improved soil and plant health parameters (Scott, 2005).
Since many experiments were done with regards to biodynamic agriculture, the researcher found it quite interesting in trying this technique, along with the others, to investigate their effect on plant parameters. Organic waste possesses a serious environmental problem globally. This can be solved by vemritechnology, including vemriwash and vermicom- post, and also biodynamic preparation (500), which is an essential component of biodynamic fanning. Marry researches over the years have been conducted, whereby solid waste were used and recycled to produce organic fertilizers using different technologies. In many developing countries, there is a serious organic solid waste problem; preparing these organic fertilizers will be cost-effective, and beneficial for fanning (Arrsari, 2008). The use of organic processes and materials in agriculture also helps to prevent environmental hazards, soil damage, and nutrients loss due to the excess use of toxic chemical fertilizers and pesticides (Nath et al., 2009).
EARTHWORMS IN SOIL FERTILITY AND MICROBIAL MANAGEMENT
Earthworms are key to maintaining soil fertility and nutrient cycling. Earthworms process organic nutrients for the efficient growth of plants.
Earthworms also contribute to the physical and chemical changes in the soil, transforming in terms of soil fertility and affect plant growth. Earthworms release casts into the soil, which is enriched with beneficial microorganisms. Earthworms are classified into three ecological types. Epigeics (Eisenia fetida, Eudrilus engenioe) are surface dwellers serving as efficient agents of comminuting and fragmentation of leaf litter. They are phytophagous and generally have no effect on the soil structure as they cannot dig into the soil. Anecics (Lampito mauritii) feed on the leaf litter mixed with the soil of the upper layers and are said to be geophytophagous. They may also produce surface casts generally depending on the bulk density of the soil. Endogeic earthworms (Octochaetona thurstoni) are geophagous and live within the soil deriving nutrition from the organically rich soil they ingest (Ismail, 2005).