ABE 101 INTRODUCTION TO AGRICULTURAL AND BIO ENVIRONMENTAL

1.0 Definition of Agricultural Engineering • Agricultural engineering is the area of engineering concerned with the design, construction and improvement of farming equipment and machinery. Agricultural integrate technology with farming. For example, they design new and improved farming equipment that may work more efficiently, or perform new tasks.

• Agricultural engineering combines the disciplines of mechanical, civil, electrical, Food science and principles with knowledge of agricultural principles according to technological principles.

1.1 Roles of Agricultural & Environmental Engineers The main role of agricultural and environmental is to solve problems found in agricultural production as well as the environmental problems. 1.3 Other Fields of Engineering The fields include: • • • Electrical and • Metallurgical Engineering • Aeronautical Engineering • Petro-chemical Engineering • Engineering and etc.

1.3.1 Mechanical Engineering It is a branch of engineering dealing with the design, construction, and use of machines. E.g Electric generators, internal combustion engines, steam and gas turbines, as well as power-using machines, such as refrigeration and air-conditioning systems.etc

1.3.2 Civil Engineering Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewerage systems, pipelines, structural components of buildings, and railways and etc.

1.3.3 Electrical and Electronic Engineering is an engineering discipline concerned with the study, design and application of equipment, devices and systems which use electricity, electronics, and electromagnetism.

1.3.4 Metallurgical Engineering Metallurgical Engineers extract, refine and recycle metals. They solve problems such as reducing corrosion, maintaining heat levels and increasing the strength of the product. 1.3.5 Mechatronic Engineering: It is a synergy of mechanical engineering, electrical engineering telecommunications engineering, and . A mechatronic engineer unites the principles of mechanics, electrics, and computer to generate a simpler, more economical and reliable system. An industrial robot is a prime example of a mechatronics system. 1.3.6 Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is similar, but deals with the electronics side of aerospace engineering.

2.0 Areas of Specialization in Agricultural Engineering • Power and Machinery Engineering, • Soil and Water Engineering, • Processing or Post Harvest , • Farm Structures and Environmental Control Engineering, • Forestry and Wood Product Engineering • .

2.1 Farm Power and Machinery Engineering

Farm Power and Machinery Engineering deals with the design, construction, operation and maintenance of power and machinery systems needed for all aspects of Agricultural Mechanization

2.2 Soil and Water Engineering This aspect of Agricultural Engineering deals with the harnessing and management of the soil and water resources of the ecosystem.

2.3 Processing or Post Harvest Systems Engineering. Post Harvest Systems Engineering This aspect of Agricultural Engineering deals with all the activities, processes, structures and machines which convert agricultural raw materials (harvested crops) into finished consumer goods.

2.4 Farm Structures and Environmental Control Engineering.

Farm Structures and Environment Control Engineering deals with the design and construction of all structures that are used in agricultural production. The structures include farm roads, residential buildings, pens, warehouses for storage and food processing, implement sheds and farm shops, storage structures and etc.

2.5 Forestry and Wood Product Engineering Forestry and wood product engineering deals with the machines required for exploiting forest products such as timber and non-timber forest products. It also handles machinery for afforestation such as loggers, tree fellers/pushers etc.

3.0 Contributions of Agricultural Engineering in National Development

• Food Security • Employment Generation • Reduction of Drudgery in • Others. Agricultural Work • Rural Infrastructural Development • Natural Resources Conservation • Industrial Development 3.1 CAREER OPPORTUNITIES IN AGRICULTURAL ENGINEERING

Jobs are available for graduates of the in the following areas. • Government Ministries. • Government Parastatal. • Private Companies and Industries • Educational Institutions • and Development Institutions • International Organizations • Self Employment

4.0 FARM POWER AND MACHINERY

• Farm power can be described as any source of energy or force that can be used in doing farm work. • Farm machinery is a mechanical device, including tractors and implements, used in farming to save labour. • The field of Farm Power and Machinery involves the application of mechanical, physical, biological and electronic principles to the solution of real-life problems or issues in crop/fruit/vegetable production and processing

4.1 SOURCES OF FARM POWER

• human • Animal • Mechanical power (Tractors + Power tillers + Oil engines) • 4. Electrical power • 5. Renewable energy (Biogas + Solar energy + Wind energy)

4.1.1 Human Power Human power is the main source for operating small implements and tools at the farm. Stationary work like chaff cutting, lifting, water, threshing, winnowing etc are also done by manual labour. An average man can develop maximum power of about 0.1 hp for doing farm work.

4.1.2 Animal Power Animal power involves the use of animal in carrying out agricultural activities. Example of animals power are camels, buffaloes, horses, donkeys, mules and elephants etc.

4.1.3 Mechanical Power Broadly speaking, mechanical power includes: • Stationary oil engines •Tractors •Power tillers • Self propelled combines.

4.1.4 Electrical Power

Electrical power is used mostly in the form of electrical motors on the . Motor is a very useful machine for . It is clean, quest and smooth running. Its maintenance and operation needs less attention and care.

4.1.5 Renewable Energy

It is the energy mainly obtained from renewable sources of energy like sun, wind, biomass etc. Biogas energy, wind energy and solar energy are used in and domestic purposes with suitable devices.

4.1.5.1 Water Power Water power is the use of water energy in agricultural activities. It can be employed as energy for doing farm work through the construction of hydro- electrical power. 4.1.5.4 Biomass Energy Biomass energy is produced from plants and organic wastes everything from crops, trees, and crop residues to manure . Crops and biomass wastes can be converted to energy on the farm.

4.1.5.3 SOLAR POWER Solar energy is the energy obtained directly from the sun in the form of short wave electromagnetic radiation. Solar energy can be used in agriculture in a number of ways, saving money, increasing self-reliance, and reducing pollution. 5.0 Classification of Agricultural Tractor

Tractor is such a machine that is used to pull or push agricultural machinery or trailers, for plowing, tilling, disking, harrowing, planting, and similar tasks in the field.

The classification of Agricultural tractor is as shown in the next slide.

Classification of Agricultural Tractor

Mode of construction Type of Drive Purpose of usage

Track type Wheel type •Row crop tractors •Utility Tractor •General purpose tractor Walking Riding • tractor type type •Garden tractor •Rotary tiller •Earth moving tractors

2 wheel 3wheel 4 wheel 5.1 Makes of Agricultural Tractors

• Massey Ferguson (MF) • Zetor • New Holland • Hindustan • Eicher • Escort • Ford • International • Swaraj • Case • Duetz • Mahindra • Harsha • Styr and etc

5.2 Functional Units of a Tractor

• Engine • Hydraulic control and • Clutch hitch system • Gear Box • Brakes • Differential unit • Power take-off • Final drive • Tractor pulley • Rear wheels • Control panel • Front wheels • Steering mechanism Engine: The engine is the tractor’s main source of power.

Clutch: The clutch engages and disengages power transmission

Gear Box: For speed and torque selection

Differential Unit: Differential unit is designed to drive a pair of wheels while allowing them to rotate at different speeds.

Final Drive: Final drive transmits the power finally to the rear axle and the wheels.

Front Wheels: Purpose of front wheel is for steering the tractor hence being light weight and small is beneficial for ease of control.

Steering Mechanism: The function of the steering system is to provide directional stability.

Hydraulic Control and Hitch System: All tractors are equipped with hydraulic control system for operating three-point hitch of the tractor.

Brakes: Brake is used to stop or slow down the motion of a tractor.

Rear Wheels: Rear wheels offer stability and weight distribution. Rear wheel are mostly large and it provides more torque, since friction is the driving force of the wheel.

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Power Take-Off : The PTO is the 'Power Take-Off' and provides rotational energy to an attachment/implement .

Tractor Pulley: The function of the pulley is to transmit power from the tractor to stationary machinery by means of a belt. It is used to operate thresher, centrifugal pump, silage cutter, and several other machinery.

Control Panel: A control panel is a flat, often vertical, area where control or monitoring instruments are displayed or it is an enclosed unit that is the part of a system that users can access, such as the control panel of a security system. 6.0 SOURCES 0F WATER FOR AND

The most common sources of water for irrigation and drainage include :- • Rivers • Reservoirs • Lakes • Rainfall • Domestic water • Groundwater and etc.

7.0 Methods of Controlling Soil Erosion

Soil erosion is a natural process in which particles of soil are moved by wind and water, and displaced to another location. There are broadly two methods of controlling soil erosion: a) Cover crops methods b) Barrier methods

a) COVER METHODS These methods all protect the soil from the damaging effects of rain-drop impact and improves soil fertility. method includes: Mulching. Bare soil between growing plants is covered with a layer of organic matter such as straw, grasses, leaves and rice husks - anything readily available. Mulching also keeps the soil moist, reduces weeding, keeps the soil cool and adds organic matter. If termites are a problem, keep the mulch away from the stems of crops Cover crop. Cover crops are a kind of living mulch. They are plants - usually legumes - which are grown to cover the soil, also reducing weeds. Sometimes they are grown under fruit trees or taller, slow maturing crops. Sometimes they also produce food or fodder. Cowpeas, for example may be used both as a cover crop and a food crop. Green manures usually legumes are planted specially to improve soil fertility by returning fresh leafy material to the soil. They may be plants that are grown for 1-2 months between harvesting one crop and planting the next. The leaves may be cut and left on the surface of the soil as a mulch or the whole plant dug into the soil. Green manures may also be trees or hedges which may grow for many years in a cropping field from which green leaves are regularly cut for use as mulch (alley cropping). Mixed cropping and inter-cropping By growing a variety of crops - perhaps mixed together, in alternate rows, or sown at different times - the soil is better protected from rain splash. Early planting The period at the beginning of the rainy season when the soil is prepared for planting, is when the damage from rain splash is often worst. Sowing early will make the period when the soil is bare, as short as possible. Crop residues After harvest, unless the next crop is to be immediately replanted, it is a good idea to leave the stalks, stems and leaves of the crop just harvested, lying on the soil. They will give some cover protection until the next crop develops Planting trees among agricultural crops helps to protect the soil from erosion, particularly after crops are harvested. The trees will give some protection from rain splash. Fruit, trees, legume trees for fodder or firewood and alley cropping all help reduce soil erosion. Minimum cultivation Each time the soil is dug or ploughed, it is exposed to erosion. In some soils it may be possible to sow crops without ploughing or digging, ideally among the crop residue from the previous crop. This is most likely to be possible in a loose soil with plenty of organic matter. b) BARRIER METHODS Barrier methods all slow the flow of water down a slope. This greatly reduces the amount of soil which run-off water can carry away and conserves water. To be effective any barrier must follow the contour lines. The barrier methods include:- Contour ploughing Whenever possible all land should be ploughed along the contour line - never up and down, since this simply encourages erosion. In some cultures this may be very difficult due to the pattern of land inheritance. Man-made terraces Well-built terraces are one of the most effective methods of controlling soil erosion, especially on steep slopes. However, terraces require skill and very hard work to build. Each is levelled - first by levelling the sub-soil, then the top soil - and firm side supports are built, often of rock. Man-made terraces are unlikely to be an appropriate method in countries with no tradition of terrace building. Contour barriers Almost any available material can be used to build barriers along the contours. Here are some examples: old crop stalks and leaves, stones, grass strips, ridges and ditches strengthened by planting with grass or trees. Natural terraces Planted grass along the contour lines. We used fibrous grasses with a dense root system such as Napier grass, Guatemala grass and Guinea grass. The strips of land in between were cultivated. As the soil is cultivated, nature moves the soil to form a natural terrace. The rainwater passes through the grass strip, depositing any soil carried behind the grass. In our experience in Bangladesh and Brazil, rains formed natural terraces within five years. Once well established, the grass barrier can be planted with banana, pineapple, coffee, fruit or firewood trees.

8.0 Water Control Structures

A Water Control Structure means a permanent structure placed in a farm canal, ditch, or subsurface drainage conduit (drain tile or tube), which provides control of the stage or discharge of surface and/or subsurface drainage. The primary purpose of the water control structure is to improve water quality by elevating the water table and reducing drainage outflow. A secondary purpose is to restore hydrology in riparian buffers to the extent practical. Water control structures include the following:- Fig.1 Stilling basin 1. Stilling basin:- A depression in a channel or reservoir deep enough to reduce the velocity or turbulence of the flow.

Fig.2 Drop spillway

2. Drop spillway:- It is a weir structure. Flow passes through the weir opening, drops to an approximately level apron or stilling basin and then passes into the downstream channel. Drop spillway is one of the most commonly used gully control structures. It is mainly used at the gully bed to create a control point.

Fig.3 Gravity chute

3. Chute:- It is a sloping channel or slide for conveying things to a lower level.

fig4. Flume

4.Flume:- Is a human-made channel for water in the form of an open declined gravity chute whose walls are raised above the surrounding terrain, in contrast to a trench or ditch.

Fig 5.Weir

5.Weir:- Is a concrete or masonry structure which is constructed across the open channel (such as a river) to change its water flow characteristics. Weir can be in rectangular or triangular shapes.

9.0 Drainage Control Structures

• Drainage Structures include curb inlets, drop inlets and rectangular structures which are specifically designed to collect surface runoff and deliver it to underground storm water conveyance systems. • The inlets are also available in a wide range of sizes and configurations depending on local requirements and conditions. These structures are manufactured for a variety of length, width and height combinations. They are also furnished with integral floor and top slabs.

The major drainage system would almost certainly include open channels and natural watercourses within an urbanized (or urbanizing) catchment. Natural drainage features include lakes, rivers, swamps, sea, rapids, waterfalls, cataracts, springs, deltas, fjords, sand or mud, and bays. 10.0 Soil Conservation Structures

Soil conservation is the prevention of loss of the top most layer of the soil from erosion or prevention of reduced fertility caused by over usage, acidification, salinization or other chemical soil contamination. Conservation Structures includes: • Cropping systems & tillage practices don’t always provide adequate erosion control; sometimes special structures is needed.

•Terraces •Contour bunds: small graded terraces, placed across slope to act as barrier to runoff, store water. • Culverts: allow water to pass under road, railroad tracks, etc •Storage Dams, Levees, Bank Protectors.

11. FARM STRUCTURES

• Farm structures provides shelter and conducive environment for the preservation of quality and quantity of plants and crops, increase the productivity of animals and farmers, and ensure safety and good working condition of machineries and equipment. Below are the types of farm structures and their uses.

Fig6. Farmhouse

1. A farmhouse:- is a structure used primarily as a residence for families, farmers, and workers on a farm. A farmhouse is a structure used primarily as a residence for families, farmers, and workers on a farm. It can be connected to a barn sometimes Fig7.Barn

2. BARN:-A barn is another popular type of farm structure and it is used for more than one purpose. A barn can serve as a shelter for livestock or livestock feeds like hay, grains etc. It can be also used for storage of farm produces, farm supplies, and machinery. There are different types of barns. They are named according to their purpose.

Fig8. A chicken coop or chicken house

3. A chicken coop or chicken house:- is a small structure used for keeping chickens especially the female ones. It is built basically to protect them from bad weather and also a place where they can lay their eggs for easy collections. The chickens are not kept in the coop or house all day. The chicken house has a door which allows the chicken to come outside during the day and absorb sunlight. And they sleep in the chicken house at night.

Fig 9. Brooder house

4.Brooder house:- A brooder house is a farm structure used for keeping young livestock especially poultry. This structure is a heated enclosed shelter.

Fig 10. Cow-shed

5. Cow-shed: - A cow shed can also be referred to as a barn. But it is only designed for the purpose of keeping cows.

Fig11. Stable 6.Stable: - A stable is a structure used for keeping horses, although it can also be used for keeping some other types of livestock.

Fig12. silos

7. Silo:-A silo is a storage facility for storing of grains such as corn, rice etc. such or silage. There are different types of silo such as tower silos, bunker silos, bag silos, concrete stave silos, fabric silos, etc. The most common types of silos used in modern day farming are the tower, bunker and bag silos.

Fig 13 . A Greenhouse

8. A Greenhouse: - is a special type of farm structure used for cultivating plants and crops which require regulated weather conditions. The walls and roof of a greenhouse are constructed majorly with glass or other transparent material. Most of the commercial greenhouse structures are high-tech structures used in modern day farming. Fig14. An Abattoir 9. An Abattoir:- also known as a slaughterhouse is a farm building where animals for consumption are killed before being moved to packaging department. These are just some of the very important types of farm structures. You can learn more about each of them to know about their specifications and how to construct them. You don’t need to have all of them on your farm. Only according to the type and size of your farm.

10. Milking Shed: - A milking shed is a farm structure with a very high hygienic standard used for milking. This structure is very important in places where the milk is not pasteurized.

11. Root Cellar:- A root cellar is not very common in the modern day farming. It is an underground storage facility used for storing fruits, vegetables and other foods. It also has been helpful in places where they experience winter so they can keep the foods safe in that climate.

12. Pigpen Or Sty:- A pigpen or sty is used for rearing domestic pigs. It is also known as a hog pen or pig parlour. 12. Livestock Buildings and Structures

These are structures used for handling livestock during various routine management practices or for housing the livestock. They include: crushes, dips, spray race, calf pens, dairy shed/parlour, poultry houses and structures (deep litter, coops, folds/arks, runs, battery cages), rabbit hutches, piggery/pig sty, fish ponds, silos, zero unit, bee hives

1.Crushes These are used for restraining an animal when carrying out certain livestock routine practices, such as, spraying and milking. Crushes have a holding yard and consist of a head rail and a horizontal split which allow easy access to the sides of the animals' body. The horizontal and vertical bars aid in fixing the animals' head during dehorning. The tad bar at the entrance holds an animal in. There is an open gate at the front of the crush to allow exit of the animal. Examples of the crushes: (a) A three post crush: Normally used when handling one animal. (b) A crush for a small scale : It is longer than the three-post crush. Its length is 3 m and width is 1 m. (c) A crush for holding many animals: This is mainly used during vaccination of livestock 2. Dips It is a farm structure designed to accommodate a chemical dip wash in which animals are immersed for the purpose of controlling ticks. There are two types of dips: •Plunge dips •The machakos dip

3. Spray race This is a structure used for tick control. Its main principle of operation is showering of animals with an acaricide rather than immersion. Animals walk through a confined area (race) where a pipe system with many nozzles (usually 20 - 30) are fitted at certain intervals and at particular angles. The animals are wetted as they walk through the length of the race with dip-wash sprays coming through the nozzles. The nozzles are placed at strategic places on the side, floor and overhead pipes and at such angles that the animal gets wetted from all sides. The wash is drawn from a reservoir besides the race through a centrifugal pump driven by an engine or tractor and is circulated under pressure through the piping to the nozzles. Advantages of a spray race It is faster and can spray more animals per hour than a plunge dip. Suitable for pregnant, heavy, young, goat, and sick animals as they do not get shock. Fresh wash every spraying time. It is economical. It is less laborious. No poisoning of animals due to swallowing of the acaricide

Disadvantages •It requires high technical skill to operate and ma •In wet weather, the nozzles may get clogged with dirt found in the wash. •It is only economical with a large her •High initial cost of construction.

4. Dairy shed/ parlour A dairy shed is part of the dairy unit that is used during milking. It comprises of the following parts: •A night shade. •A calf pen which should be fitted with a feed and water trough. •A feeding and watering area. •The milking section. •A feed and equipment store. There are two types of milking sheds: a)Permanent milking shed: This has a milking machine permanently installed at the milking section. b) Movable milking shed: These units are fitted with small wheels which facilitate their movement to different sites. Movable milking sheds are common in large dairy farms. Cows are fed on concentrates while in the parlour.

5. Calf Pens These are structures for housing calves. The calf pen can be either communal or individual. Individual calf pens are most suitable. They prevent cross-suckling among calves which results in hair balls in the rumen, Provide for better individual attention given to the calves. Minimize spread of diseases. Calf pens should be located near or within the dairy unit. Types of calf pens: •Permanent calf pens: These are fixed on the ground and cannot be relocated to other areas. They are prominent in the zero-grazing method of livestock rearing. •Movable calf pens: These are mobile and can be relocated to new sites as a farmer may decide. They are most common in the paddocking method of animal grazing. 13. Poultry Houses and Structures

These are housing structures used for poultry production. They should be sited in free draining areas and away from main house.All the structures must provide warmth, Be properly lit and Well ventilated. They should be kept damp-free. They include: • poultry shed run, • deep litter, • battery cage etc.

(a) Poultry shed and run This structure has a shed and run and is sometimes attached to a nest box. The run is enclosed with a chicken wire. It has a door for use by the keeper to gain entry into the run when there is need. The shed should preferably be made of wooden walls. It provides protection against bad weather and predators. It must be properly ventilated to allow free air circulation, easy to access for cleaning, collection of eggs and for the arrangement of feeding troughs. Place nest boxes inside the shed. The stand must be fitted with rat guards to prevent entry of rats into the shed.

(b) Battery cage system These are the structures used to house birds under the intensive system of poultry production. Individual birds or a few birds are confined in cages or batteries arranged from side to side. The size of the cage is about 0.5 m-per hen. A 10 cm length of feed trough should be allocated per cage. The farmer can, however, have one long feed trough that runs through several cages in each tier. Battery cage can be multiple tier, stair step or flat-deck.

(c) Coops These are specialized types of cages that are used for rearing hens that are brooding. They are commonly used in small scale, non-commercial poultry rearing systems. (d) Fold/Ark It has both the run and the shelter section. The run is covered with chicken wire mesh. It provides birds with space for exercise and to get natural vegetation and insects. The shelter part of the fold is covered with solid materials to provide protection against predators and bad weather conditions. The fold is moved to new sites at regular intervals to reduce the accumulation of bird droppings. One fold can carry up to 25 birds. Normally a fold measures about 3.5 m x 1.5 m wide x 1.5 m high. (e) Night shelters These are used in system where birds are allowed to move within a fenced enclosure called a run. Birds spend the night in these shelters but are allowed to go out and scavenge for food during the day. These structures are also equipped with laying nests. The night shelters are mostly used by small- scale, non-commercial poultry keepers. Night shelters are raised off the ground by use of stands or hung on a tree to keep off predators.

•Deep Litter This is a poultry house where birds are confined. A deep litter has a low masonry wall of 0.6 m on the leeward side. The rest of the upper part is made of wire mesh. The floor space should allow for 4-5 birds/m2. The house should contain laying boxes and perches for the hens. Keep the roof leak-proof and avoid dampness in and around the house. The building must keep away stray birds, predators and rodents.

Maintenance Practices of Poultry Houses • Regular cleaning and disinfecting of the poultry houses. • Ensure roofs are leak-proof. • Minimize entry of dust into the poultry Dust is a predisposing factor to respiratory infections in birds. • Put the poultry house into a resting period before start of a new project. • Repair broken parts of the structure. • Dusting should be don~ regularly to control external parasites 14. Rabbit hutches/Rabbitry

These are houses for keeping rabbits. The house should be painted white to reflect much of the solar radiation that causes sunburn in rabbits. A rabbitry unit is divided into two parts: • The feeding and watering area • The resting and exercising area. A wire netting of 1 cm mesh or wooden slats fixed 1 cm apart can be used for the floor. It has a hinged door for easy opening and closure. The hutch is fitted on stands of about 60 cm above the ground. Inside the hutch, provide feed and water troughs and a nest box of size 38 cm X 25 cm X 20 cm. Place the hutch under a shade and in a site protected from the prevailing wind direction. Features Of A Good Rabbitry 1.Adequate ventilation and well lit but protected from direct sun rays. 2.Spacious: Space requirement for a doe is 80 - 115 cm". 3.Must be protected from direct rain and wind. 4.The sides and floor of the hutch should have chicken wire mesh. 5.The rabbitry must be safe from predators and pests like dogs, cats and snakes 6.It should be raised off the ground. The floor of a rabbit hutch may be made of solid wood or wire mesh.

Maintenance of a Rabbit Hutch 1. Repair broken parts. 2. Repair leaking roof to prevent dampness inside. 3. Paint the wooden posts to last long. Apply old engine oil to keep off ants. 4. Clean regularly.

15. Piggery /Pig Sty Pigs are housed in a structure known as piggery or pig sty. Pigs are very sensitive to extreme weather conditions; therefore a piggery should provide warmth and be well ventilated.

Essential features of a piggery

• Farrowing pen: – It is used for farrowing and ensuring the safety of the piglets. The pen is provided with a farrowing crate to prevent the sow from lying on the piglets and a heat source to protect the piglets against chilliness. It contains a creep area where only the piglets can access creep feed. • Weaners pen: – It is where weaned pigs are kept. It should have a feeding, watering and resting section. • Boar pen: – This is where breeding boars are kept. It allows room for sows to be served during the breeding season. • Gilts pen – It is used for keeping young female pigs up to the age of service (usually 12 months).

16. Fish Ponds

These are structures that are constructed in the farm for rearing fish. Fish ponds require a large amount of water; therefore it is important to construct them near a water source such as a stream or a river. The water should come from a higher ground so that it flows downhill into the fish pond and be drained out easily. The site of a fish pond must be well selected for successful construction and maintenance. Procedure of establishing a fish pond include the following:-

(i) Site selection: Select a suitable place where water flows gently from the source. The ground soil of high water-retention capacity is preferred. (ii) Site marking: After selecting the site, use pegs to mark the channel from the river, the entrance and exit of the pond, and the channel to take water back into the river. (iii) Clearing the land: All vegetation is cleared off the site of the pond area. (iv) Digging the pond: Soil is dug out. The top soil is placed in a particular place as it will be reuse. the upper side of the pond is dug 0.5 m deep and the lower side of the pond 1.5 m. (v) Construction of dyke: The dyke is the wall constructed all round the pond. Pond floor (vi) A cone is established by digging a trench 0.5 m wide and lower than the general level of the pond bottom. It is then filled with clay soil and compacted or concrete is used to help prevent water seepage. Parts of a fish pond Inlet: This is the canal or a pipe that brings water into the fish pond. It is made in the dyke slightly above the level of the pond water. A screen of fine mesh is filled across the inlet to prevent the entry of undesirable species of fish into the pond. Outlet: This is made at the deeper end of the pond just a little above the bottom of the pond. A pipe is connected to it to make the outlet firm. A screen is fitted at the mouth of the outlet to prevent the fish from escaping from the fish pond. It is used to drain water back into the river during harvesting. Spill way: It is the channel that allows removal of excess water from the pond. It is made at the top of the dyke on the lower side of the pond. The spillway prevents the water from overflowing on the dykes. Factors to be considered when sitting a fish pond (i) Topography: The selected area should be gently sloping. This allows easy flow of water into and out of the pond. It also helps avoid flooding of the fish pond. (ii) Accessibility to the fish pond: It should be located near the homestead or where it can be reached easily. (iii) Security of the area: The site must be protected from tresspassers, thieves or predators such as mongoose, kingfishers, etc. (iv) Free of pollutants from sewage and dumping sites. (v) Nearness to water source: A fish pond should be constructed near a reliable water source. This ensures an adequate water supply. (v) Soil type: The ground where the fish pond is constructed must have soils with a high water retention capacity to minimize water seepage. Clay soil is preferred. 17.0 HOUSING UNITS FOR CROP STORAGE

17.1 storage: Storage is the art of keeping the quality of agricultural materials and preventing them from deterioration for a specific period of time beyoung their normal shelf life. Storage is essential for the following reasons: • Perishable nature of agric and bio materials. • Provision of food materials all year round. • Pilling provisions for large scale processing. • Preservation of viability. • Prevention of original varieties from extinction. • Preservation of nutritional quality. • Weapon for national stability • Price control and regulations. • Optimization of farmers gain. • Opportunity for export market etc.

17.2 Storage Structures The facilities that house stored materials for the purpose of preserving their qualities are called storage structures. Broadly storage structures are classified as: • Traditional structures: Small sized and short term with high level of infestation. They are mostly made of unrefined local materials. • Modern structures: Mostly large capacity and long term with better regulation of the storage environment. They are made of improved and refined materials. 17.2.1 Traditional Storage Structure They are mostly for short term and small scale storage. They require low level scientific knowledge to construct, operate and maintain. The traditional storage structure include: Aerial Storage Storage on the Ground Domestic Structure Rhombus Traditional Cribs Barn Shelf Pits / Underground Storage etc

17.2.2 Modern Storage Structures Modern storage structure is mostly used for medium or long term and medium or large scale storage. These include: •Improved crib •Ware house •Silo/bin •Controlled atmosphere storage system •Refrigerator •Cold storage •Evaporative coolant system •Hermetic and nitrogen storage system. 18.0 Dam, Hydraulic Structures and Farm Roads

18.1 Dams: Dam, structure built across a stream, a river, or an estuary to retain water. Dams are built to provide water for human consumption, for irrigating arid and semiarid lands, or for use in industrial processes. They are used to increase the amount of water available for generating hydroelectric power, to reduce peak discharge of floodwater created by large storms or heavy snowmelt, or to increase the depth of water in a river in order to improve navigation and allow barges and ships to travel more easily. Dams can also provide a lake for recreational activities such as swimming, boating, and fishing. Many dams are built for more than one purpose; for example, water in a single reservoir can be used for fishing, to generate hydroelectric power, and to support an irrigation system. Water-control structures of this type are often designated multipurpose dams.

Fig15. Dam 18.2 Hydraulic Structures: A hydraulic structure is a structure submerged or partially submerged in any body of water, which disrupts the natural flow of water. They can be used to divert, disrupt or completely stop the flow. An example of a hydraulic structure would be a dam, which slows the normal flow rate of the river in order to power turbines. A hydraulic structure can be built in rivers, a sea, or any body of water where there is a need for a change in the natural flow of water. Hydraulic structures may also be used to measure the flow of water. When used to measure the flow of water, hydraulic structures are defined as a class of specially shaped, static devices over or through which water is directed in such a way that under free-flow conditions at a specified location (point of measurement) a known level to flow relationship exists. Hydraulic structures of this type can generally be divided into two categories: flumes and weirs. Hydraulic Structures is presenteed in fig 16 Fig16. Hydraulic Structures 19.0 Farm Roads

A farm road is a state road or county road that connects rural or agricultural areas to market towns. It is a service road that serves predominantly agricultural or forestry purposes and has only local significance. 19.1 Type of Farm Roads: From the service point of view the farm roads shall be grouped into the following two classes. • The road serving farm stead and • The road serving fields According to the construction and materials used the roads may be grouped into two types;

The flexible road made up of layers of various materials such as lime stone, gravel, kanker, red earth etc. The rigid road made up of cement concrete.

FARM STEAD ROAD: The farmstead road generally carries traffic of greater weight and density than the field road. Therefore it should have a smooth, hard surface requiring minimum maintenance and easy cleaning. For this, the concrete is most suitable. If any existing flexible road is to be made use of, then it should be reconditioned with a wearing surface.

FIELD ROAD Field road should have sufficient hardness and not necessarily smoothness. Hence all that is required is a good hard base with a surface of gravel of broken stone. The base may be constructed using rubble, broken brick, late rite or any other cheap material available in the locality.

19.2 THE REQUIREMENTS OF A GOOD ROAD: An ideal road should be perfectly straight, level, smooth hard and dry. Such perfection can of course be rarely reached and hence in practice a compromise of all the above requirements is to be made. The requirement are as follows:- •Straightness •Levelness •Smoothness •Hardness and •Dryness

19.3 CLASSIFICATION OF ROADS: According to the materials used for construction, roads may be classified as 1.Earthen roads 2. Gravel roads 3. Water bond macadam roads 4. Tar or bitumin roads and 5. Cement concrete roads Earthen roads:- are temporary roads made up of earth available in the locality. They are suitable for low speed vehicles such as bullock drawn carts. Gravel roads :- are better than earthen roads and are stable for light traffic. Water bound macadam roads:- are still better, and suited for heavy traffic of low speed vehicles. Bitumen or tar roads:- are roads that are coated with bitumen or tar and they are suitable for rubber tyred vehicles of both slow and high speed. Cement concrete roads:- are stable and suited for all kinds of traffic. Each of the roads has its own qualities which influence the choice and design. The choice of road depends mainly on the traffic, finance and local conditions. 20. FOOD PROCESSING

Food processing is the technique which converts raw food items into well-cooked and preserved eatables. The following are some techniques and methods that are used to convert raw food into processed food:- • Drying • Preservation • Smoking • Freezing • Salting • Vacuum packs • Sugaring • Pickling

20.1 Storage and Processing Machines: Storage and processing machine include: •Separators •Shellers/Threshers •Size reduction machines •Mixers •Feed mills •Dryers •Crushers •Pelleters •Decorticators etc. 21.0 SHELLERS/THRESHERS

The operation of detaching the grains from the ear head, cob or pod is called threshing. It is basically the removal of grains from the plant by striking, treading or rupturing. The threshing mechanism, which separates the grain from the stalks, consists mainly of a revolving cylinder and the concaves. A feeder beater is usually located in front of the cylinder and at the upper end of the elevator-feeder to assist the elevator-feeder in feeding the grain to the threshing mechanism. Components of a Thresher They include: •Feeding unit (Feeding Hopper) •Threshing unit: •Cleaning unit •Power transmission unit •Main frame •Output unit (grain outlet) •In some cases Transport wheels.

Types of threshers: The types of thresher include; •Maize thresher •Wheat thresher •Paddy •Rice threshers etc. •Multi-crop

Fig17 . Wheat thresher.

22.0 SIZE REDUCTION MACHINE

Size reduction is a process of reducing large solid unit masses into small unit masses, coarse particles or fine particles. Size reduction process is also termed as Comminution or Diminution or Pulverizations. Size reduction machinery: • Crushers • Grinders • Fine grinders

Fig18. Jaw crusher

Crushers: Crusher is mostly used to break large pieces of solid materials into small lumps by Squeezing or pressing the material until it breaks.

Fig19. Gyratory Crusher

Types of crushers i. Jaw crusher ii. Gyratory crushers

Grinders: Grinder is used to mill the grains into powder Types of grinders a. Attrition mill b. Hammer Mill c. Impactors d. Rolling Compression Mill Attrition mill Attrition mill is also known as burr mill. Grains are rubbed between the grooved flat faces of rotating circular disks. One plate is stationary and fixed with the body of the mill while the other one is rotating disk. Material is fed between the plates and is reduced by crushing and shear. The axis of the roughened disks may be horizontal or vertical. The mill has different patterns of grooves, corrugations on the plates perform a variety of operations.

Fig.20 Attrition mill

-Hammer mill Hammer mill Consists of high speed rotor rotating inside a cylindrical casing. Attached to the rotor is a fixed or swinging hammer and materials fed into the mill from the top of the casing and is broken by the rotating hammers and fall out through a screen at the bottom. Size reduction takes place by impact force..Hammers are rotated between 1550 to 4000 rpm, strike and grind the material until it becomes small enough to pass through the bottom screen; fineness of grinding is controlled by the screen size and can grind tough fibrous solids, steel chips, food grains, hard rock etc. Ball mill It is a cylindrical or conical shell slowly rotating about a horizontal axis. The shell is made of steel lined with high carbon steel plate, porcelain or silica rock. Half of its volume is filled with solid grinding balls; Size reduction is achieved by impact of the balls when they drop from near the top of the shell. When the ball mill is rotated, the balls are carried by the mill wall nearly to the top and are released by the gravitational pull and drop to the bottom and picked up again.The energy consumed in lifting the balls is utilized for grinding job.Centrifugal force keeps the ball in contact with the mill wall.

Fig 20. Roller mills

Roller mills are similar to roller crushers .They have smooth or finely fluted rolls, and rotate at differential speeds. It is widely used to grind flour and Because of their simple geometry, the maximum size of the particle that can pass between the rolls can be regulated.