The agricultural engineers and other scientists have humorous duty in developing new practices that will permit storage in the soil profile of greater percentage of the available precipitation.
Design of effective level bench terrace system with special water catchments areas, tillage practices that modifies the soil surface configuration so as to refrain precipitation and reduce the total evaporation potential and surface evaporation control through the use of mulching and films are all challenges for engineers.
Irrigation and Drainage Engineering: Irrigation is defined as the application of water to land using means other than the natural rain, the purpose of which is to provide sufficient water for plant growth and productivity.
Irrigation is necessary to provide enough water to fill the deficit arising from the depletion of soil moisture from the combine action of two separate phenomena of evaporation and transpiration. Land drainage deals with the control of water logging and soil salinization in agricultural lands. In flatlands, a first problem emerges if soil infiltration rates are low and rainfall or irrigation water stands on the ground surface in small depressions or at the edges of the irrigation basin.
This problem can be solved by leveling and smoothing the land and providing it with a uniform slope for excess water to flow through furrows or shallow ditches toward the surface drainage outlet. Surface water is discharged into a collector drain through pipes to prevent the erosion of the open ditch bank. Post Harvest Systems Engineering: This deals with the processes and machines required to convert agricultural raw materials or products into finished consumer goods.
It involve, harvesting, transporting, handling, storage, processing and packaging 5. Farm Structures and Environmental Control Engineering: Farm structures include farmstead, settlements, animal houses, storage structures farm and allied products, machinery and processing equipment house etc. These structures need specialized designs.
Control of environmental factors, external and within in the structures, waste disposal systems, biogas generation etc are also involved. Operations and management of food processing machines such as rice mills, flourmills, vegetable oil processing outfits, beverages and biscuit manufacturing, bread and other confectioneries. Wood Products Processing Engineering: This branch of engineering has not been fully developed in Nigeria educational curriculum.
It involves the study of engineering properties of woods, composite products from wood and associated wood products processing; design of machines required for forestation projects and for exploiting forestry products. This includes machines for planting, pruning, logging, transporting, milling and other wood processing machines.
Emerging Technologies in Agricultural Engineering: The discipline is currently undergoing major and important changes as it responds to global economy. The use of computer and communication ICT equipments for Data acquisition, machine control, information management and simulation and prediction of agricultural systems are becoming popular. Biotechnology involves the engineering of biological systems.
Waste recycling, alternative to fossil fuel- vegetable and fruit oil-fuels etc. Renewable energy resources such as harvesting and utilization of solar, water wind energy for agricultural production, processing and handling. Advancements is Agricultural Engineering Specialization Agricultural Engineering has advanced to the extent that the scope has been widened to embrace the various emerging technologies in the field and thus the following specialized categories have been identified: 1.
Biological Engineering Biological engineering is one of the most rapidly growing sub-disciplines of agricultural engineering that applies engineering practice to problems and opportunities presented by living things and the natural environment. Areas of interest range from environmental protection and remediation, food and feed production, medicine and plant-based pharmaceuticals and packaging materials.
Others may develop techniques and strategies for natural pest control and treatment of hazardous wastes, for composting, and for enzyme processing of biomass, food, feed, and waste 2. Natural Resource Engineering These agricultural engineers are equipped with expertise in environmental work to better understand the complex mechanics of these resources, so that they can be used efficiently and without degradation.
These engineers determine crop water requirements and design irrigation systems. They are experts in agricultural hydrology principles, such as controlling drainage, and they implement ways to control soil erosion and study the environmental effects of sediment on stream quality.
Natural resources engineers design, build, operate and maintain water control structures for reservoirs, floodways and channels. They also work on water treatment systems, wetlands protection, and other water issues. Power Systems and Machinery Design Engineering These agricultural engineers focus on designing advanced equipment, making it more efficient and less demanding of our natural resources.
They develop equipment for food processing, highly precise crop spraying, agricultural commodity and waste transport, and turf and landscape maintenance. Their work remains challenging as technology advances, production practices change and equipment manufacturers expand globally.
Structures and Environmental Engineering These agricultural engineers understand the importance of creating and maintaining a healthy environment for growing agricultural commodities and for the labourers who produce them. They also understand that our natural resources must not be diminished, in quality or availability, by agricultural operations. Toward these ends, these agricultural engineers are equipped with expertise in structures and environment to design animal housing, storage structures, and greenhouses, with ventilation systems, temperature and humidity controls, and structural strength appropriate for their climate and purpose.
They also devise better practices and systems for storing, recovering, reusing, and transporting waste products. Food and Bioprocess Engineering Food, fiber, and timber are only the beginning of a long list of products that benefit from efficient use of our natural resources. The list includes biomass fuels, biodegradable packaging materials, pharmaceutical and other products. These engineers understand microbiological processes and use this expertise to develop useful products, to treat municipal, industrial and agricultural wastes, and to improve food safety.
They are experts in pasteurization, sterilization, and irradiation, and in the packaging, transportation and storage of perishable products. Food and processing agricultural engineers combine design expertise with manufacturing methods to develop economical and responsible processing solutions for the industry as well as look for ways to reduce waste by devising alternatives for treatment, disposal and utilization.
Information and Electrical Technologies Engineering The application of information and electrical technologies in agriculture is very versatile. It is applied to virtually all the other sub-disciplines of agricultural engineering, from machinery design to soil testing to food quality and safety control.
Geographic information systems, global positioning systems, machine instrumentation and controls, electro-magnetics, bio- informatics, bio-robotics, machine vision, sensors, spectroscopy are some of the exciting information and electrical technologies being developed and used today in agriculture and agro-based industry. Forest Engineering Agricultural engineers apply engineering principles to solve natural resource and environment problems in forest production systems and related manufacturing industries.
Forest engineers are involved in a full range of activities in natural resource management and forest production systems. Energy Engineering Energy is needed to power the machines, devices, and systems in our homes and workplaces. But many of the energy sources are nonrenewable and create undesirable byproducts.
Agricultural engineers are at the forefront of the effort to identify and develop viable energy sources such as biomass, methane, and vegetable oil and to make these and other systems cleaner and more efficient. These engineers also develop energy conservation strategies to reduce costs and protect the environment, and they design traditional and alternative energy systems to meet the needs of agricultural operations.
Aquacultural Engineering As natural fish supplies are threatened, agricultural engineers are needed to help design farm systems for raising fish and shellfish, as well as ornamental and bait fish.
They specialize in water quality, biotechnology, machinery, natural resources, feeding and ventilation systems, and sanitation. They seek ways to reduce pollution from aquacultural discharges, to reduce excess water use, and to improve farm systems. They also work with aquatic animal harvesting, sorting, and processing. However, other engineering needs also present themselves in nursery and greenhouse operations such as equipment for transplanting; control systems for temperature, humidity, and ventilation; and plant biology issues, such as hydroponics, tissue culture, and seedling propagation methods.
Safety and Health in Agricultural Engineering Farming is one of the few industries in which the families work and live on the premises and are at risk for injuries, illness, and death. Agricultural engineers analyze health and injury data, the use and possible misuse of machines, and equipment in compliance with standards and regulation.
They constantly look for ways in which the safety of equipment, materials and agricultural practices can be improved and for ways in which safety and health issues can be communicated to the public.
Advances in Agricultural Engineering Advances in Agricultural Engineering technologies have been listed by the American National Academy of Engineering as one of the most significant engineering achievements of the millennium. These advances in technologies have constituted one of the most important inputs into agricultural production which is the basis for human survival. In the following areas, Agricultural Engineering technologies have made significant advancement.
Education and training: Education and training in agricultural engineering has provided the human foundation for further development of this important technical discipline by assuring food security for future generations and a sustainable use of the natural resources.
Academic curricula are being updated today so that it would better correspond to market demands and expected developments in the agro-industrial sector.
Farm Implements and Machinery: Various developments and advances have been made in such areas as land leveling with the laser-beam technology Laser-guided Leveller. Other recent developments include two-row vegetable transplanter, Flail-type Forage Harvester-cum-Chopper which could harvest forage of mm size. Flail-type Chopper-cum-Spreader. Cultivator frame Banana-Clump Remover has been developed for removing banana suckers, Light-weight power-tiller for hill side agriculture etc iii.
Stationary Machinery High-capacity Pigeon pea Thresher, Pedal-operated Potato-slicer, cassava lifter, grain cleaners etc. Design-refinement in Mills etc was other areas of rapid developments which are indigenous to Nigerian engineers.
Ergonomics studies have also increased in the evaluation of the commercially available human-machine interface systems such as pedal operated systems, Manually-operated Hanging- type equipments etc. Post-harvest engineering and technology has led to the development of candies and bars from mango, guava, banana and pineapple with different combinations of soymilk, soyflour, cashew nut, pilot-scale puffing machine to process kg raw-potatoes.
Electronics and Mechatronics Systems: Replacing mechanical functionality with electronic functionality might also reduce manufacturing costs. For example, the same electro-hydraulic valves might give different optimal performances in different applications. Other advances include plastic mulch for economizing irrigation-water in baby corn resulting in Bio- diesel from oil of non-edible plants etc Career Opportunities in Agricultural Engineering In the course of his career, an agricultural engineer received training in mechanics of machine heat transfer and thermodynamics of engine, fluid mechanics and dynamics, theory and design of machine and machine elements, engineering drawing design of structures, thermal environment, energy utilization, hydrology, soil and water conservation, surveying, systems control and analysis, principles of crop production, properties of agricultural materials, management principles and motivation economics and industrial engineering.
He is therefore equipped to carry out designs and operation of machines, undertake waste management and sewage disposal, design and analysis of agricultural buildings such as poultry houses and associated structures and many more. Engineering technology graduates are prepared to work as part of the engineering team to implement and improve existing technology. The agricultural engineering technology prepares students to be part of the engineering technology function for governmental agencies, manufacturing, sales and service companies.
The environmental engineering technology option prepares students to solve technical environmental problems. They work to reduce the release of pollutants to the environment, to prevent harmful effects of pollution, to clean up contaminated areas and to design products and production systems that minimize the generation of waste. Agricultural engineering graduates have in the past found jobs in the following areas of the economy; 1.
Government ministries and parastatals: As water resources, environment, works engineers and instructors. Educational Institutions: educational institutions in Nigeria include Colleges of Agriculture, Education, Technology including university and polytechnic. Self Employment: this area has not been fully explored. Though notable engineers such as Sahara Engineers in Ibadan etc. Agricultural Engineering and National Development Agricultural Engineering has become one of the most effective and powerful tool in national agriculture development.
This recognition has led to more research and more advancement in agricultural engineering particularly in machinery design, post-harvesting technologies and greenhouses, ergonomics and safety, work organization, environmental protection and sustainable land development over the years. Agricultural Engineering plays a pivotal role in the development of the country through 1. Food Security- obtainable when food is abundantly produced above subsistence level and all other factors of production duly monitored.
Reduce drudgery in agricultural operations. Development of rural infrastructure 4. Conservation of natural resources such as soil and water etc. Environmental management 6. Industrial development 7. Give the definition the following terms i. Agricultural Engineering ii. The Agricultural Engineer Question 2 a. List at least 5 areas of agricultural engineering specialization in Nigeria b. Explain the role of two of the listed specializations c. Agricultural Engineering has advanced to the extent that the scope has been widened to embrace the various emerging technologies in the field list three of such specialized categories which have been identified: Question 3 a.
In which areas has Agricultural Engineering technologies made significant advancements? Edited by Prof. Mijinyawa Y. Agricultural Engineering Education in Nigeria. Invited Overview Paper No. NSE articles of association The upper region of this horizon is often oxidised to a considerable extent. It is from this horizon that the bulk of the material is often borrowed for the construction of large soil structures such as earth dams. Each of these horizons may consist of sub-horizons with distinctive physical and chemical characteristics and may be designated as A1, A2, B1, B2, etc.
The transition between horizons and sub-horizons may not be sharp but gradual. At a certain place, one or more horizons may be missing in the soil profile for special reasons.
Characteristics of each horizon A-Horizon: Light brown loam, leached B-Horizon: Dark brown clay, leached C1-Horizon: Light brown silty clay, oxidised and unleached C2-Horizon: Light brown silty clay, unoxidised and unleached Soil structure The shape and arrangement of soil particle is called structures.
In a broader sense, consideration of mineralogical composition, electrical properties, orientation and shape of soil grains, nature and properties of soil water and the interaction of soil water and soil grains, also may be included in the study of soil structure, which is typical for transported or sedimented soils. Structural composition of sedimented soils influences, many of their important engineering properties such as permeability, compressibility and shear strength.
The following types of structure are commonly studied: 1 Single-grained structure: Single-grained structure is characteristic of coarse-grained soils; with a particle size greater than 0. Gravitational forces are higher than the surface forces and hence grain to grain contact results. Due to the relatively smaller size of grains, besides gravitational forces, inter-particle surface forces also play an important role in the process of settling down.
In the formation of a honey-comb structure, each cell of a honey-comb being made up of numerous individual soil grains.
The structure has a large void space and may carry high loads without a significant volume change. The structure can be broken down by external disturbances. Figure Honey-comb structure 3 Flocculent structure: This structure is characteristic of fine-grained soils such as clays. Inter-particle forces play a predominant role in the deposition. Texture of a soil is reflected largely by the particle size, shape, and gradation. The concept of texture of a soil has found some use in the classification of soils into three: clay, silt and sand.
Clay is the finest while sand is coarse. Imagine what life would be like if your local drinking water source was unsafe to drink, or there was not enough available for daily needs-if you had to rely only on bottled water brought from outside. The water- saturated soil, known as the aquifer, extends in some places to a depth of approximately feet meters , then grows more shallow toward the edges of the land as seen in the cross-section. Recharge of ground water supply by water spreading, recharge well, replenishment, irrigation and similar practices provides another means of water resources development of small quality of water supply is important to livestock, farmsteads and other special irrigation uses.
Surface water The following are the major sources of surface water: 1. Rivers 2. Streams and rivulets 3. Storm water with no definite paths. For small supplies, water is pumped from the river or lake and piped to where it is required e. Pumping of water is subject to some fluctuations ranging from uninhibited flow during the rainy season to little or no flow when the rain have ceased.
In order to prevent these fluctuations, structures such as dams are built to impound water during the time of uninhibited flow. Groundwater water When water is drawn through a well, water moves through the aquifer from the area around it. The size of this area, called the zone of contribution, varies according to the rate of pumping and the direction of groundwater flow. It is very important to protect the zone of contribution from pollutant sources. Good planning and management are needed in order to maintain high water quality into the future.
Zones of aeration and saturation Soils have zones of aeration and saturation. The zone of aeration is above the water table, where the openings in the soil are filled with air. In the zone of saturation, all the open spaces in the soil are filled with water. Plant roots must have aeration as well as moisture.
The saturated sponge will accept no more water, and all air space had been replaced by water. Saturated zone and the unsaturated zone can be distinguished. Water contained in saturated zones is important for engineering works, geologic studies water supply development and petroleum engineering. Utilization of groundwater: Its use in irrigation, industries, municipalities and rural homes continues to increase. Terms associated with groundwater 1. Aquifer: This is a geologic formation having structures that permit appreciable amount of water to move through it under ordinary field conditions.
They are in geologic formations like: limestone deposits, volcanic rocks, sandstones, crystalline and metamorphic rocks, and unconsolidated aluminum or rock materials derive from erosion of bordering mountains. Types of aquifers a. Confined aquifer — body of water trapped between two confirming impervious layers. When such body of water is penetrated by a borehole or well, water rises into the well above the surround water table level.
Unconfined aquifer: An aquifer in which water table serves as the upper zone of saturation. Perched aquifer: A special case of unconfined aquifer. A body of ground water is separated from the main body by an imperious layer.
Aquiclude: An impermeable formation which may contain water but is incapable of transmitting it in significant quantity. Clay is an example. Aquifuge: This is an impermeable formation that neither contains water nor is capable of transmitting it.
Granite is an example. Groundwater yield; The quantity of ground water which can be withdrawn without impairing the aquifer as a water causing contamination or creating economic problem from a several increase pump lift. Ground water recharge: Return of water into the soil to replace what has been abstracted in order to increase ground water yield. Water enters the formation from the ground surface or from the body of surface water after which it travels slowly to the surface by action of natural flow, evaporation or extraction by man.
Shallow wells are dug, bored, drived or jetted. Deep wells are drilled by cable tools, hydraulic, rotary or reverse rotary methods. Testing boreholes and well logs It is a common practice to put down test borehole to determine depths of ground water, quality of water and physical characteristics and thickness of aquifer etc before drilling well in new areas.
The diameter of such test borehole is between inches. During drilling of test boreholes, a record or log is kept of the various formations and the depth of which they are encountered. Careful analysis further helps to obtain information about the stratum.
Types of water well 1. Shallow well: This include a. Dug wells: These are the commonest and vary in depth from 10 to 40 feet depending on the position of the water table.
They are hand drilled and lined with casing of wood, brick or concrete and equipped with hand operated fetcher for water lift. It can yield between — gpm. Figure Bucket lift in closed well Erik Nissen-Petersen b. Bored well: Bored well exists where the water table is at shallow depths in an unconsolidated aquifer.
Driven wells: This consists of a series of connected lengths of pipes driven by repeated impacts into the ground to below the water table. A steel cone protects the screened range between cylindrical sections at the bottom. Figure Pump driven well Erik Nissen-Petersen d. The yield is small. Deep wells Most deep and high capacity wells are constructed by drilling. Three basic methods are employed in construction as follows: a.
Cable tool method Peroussion method b. Hydraulic rotary method c. Reverse rotary method Each method is particularly suited for drilling in certain formations. Well completion development and test for yield Well completion provides for easy entrance of ground water into the well with minimum resistance. Perforated or screen casing used at the back provide filtration of water.
Gravel packing is also often used. Following well completion a new deep well has to be developed to increase its specific capacity, prevent sanding and obtain maximum well life. Compressed air can be used to loosen the fine materials surrounding the discharge pipe. The yield and drawdown is tested for after development. A test is accomplished by measuring the static water level after which it is pumped at a maximum rate until the water level stabilized.
The depth is noted. Earth dams 2. Concrete dams 3. Rock-fill dam The choice of material depends upon: 1. The geology of the dam site 2. The cost of various alternatives Foundation material below the dam must be water tight, or capable of being made water tight by such means as grouting. Purposes for which dam may be developed Dam projects are developed for the following purposes among many others: 1.
Domestic and municipal purposes: Dams are constructed to serve such purposes as drinking, household use, gardening, park etc. Industrial uses: Dams could serve water for production uses in factories, namely, breweries, distilleries, food preparations, bottling industries etc.
Agricultural uses: Dams are equally useful for irrigation purposes, dairying, inland fishery and industries. Power development: Dams also serve as power source in hydro power generation and distribution. Flood control: Dams could be used in control of excess water from flood, or swamp 6. Wildlife: Water is impounded in dams to provide water for wildlife — birds and animals. Recreation: Dams serves water requirement in boating, swimming development parks and tourist attractions.
Water conservation purposes: Dams can be used for ground water recharge where water is impounded, and allow infiltration and percolation opportunities. Feasibility studies of dam development Thorough studies should be carried out to ascertain the success, usefulness, and the economic soundness of the dam project. The feasibility of engineering work, wisdom of investment, the overall benefit to the owners among other things should be investigated.
Salient items to investigate include: 1. Site specific condition with respect to: a. Soil stability b. Adequate impoundment area c. Suitable reservoir location d. Suitable construction materials etc. Hydrological data Hydrological data of the location include; flow records, flood record studies, sedimentation and water quality studies, ground water table in the vicinity of dam or reservoir, water rights, climatologic data evaporation , temperatures, wind , construction costs, maintenance costs, economic benefits, social benefits, unquantifiable benefits such as scrutiny consideration, national pride etc.
A report justifying the project or suggesting alternatives should be written following the investigations. Selection of dam type The following physical factors govern the selection of dam type.
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