Agricultural Engineering BoardReview Materials

FARM MACHINERY AND MECHANIZATION

Prepared by

Paterno C. BorlagdanAgricultural EngineerRPAE No. 0003253

January 2000(Reproduction with Permission Only)

FARM MACHINERY AND MECHANIZATIONPrepared by: Engr. Paterno C. Borlagdan

Define the following terms:

Agricultural engineering

Factor of safety Landside Pay back period

Automatic draft control Three-point hitch Share Cash flowTheoretical field capacity

Coefficient of traction

Moldboard Break-even point

Effective field capacity Traction efficiency Disc plow Salvage valueHeadland Furrow Integrated pest

mgtBoom valve

Horizontal suction (in plow)

Back furrow Transgenic rice Market value

Vertical suction (in plow)

Furrow slice Global warming Elastic demand

Dead furrow Furrow wall Robotics Inelastic demandDynamometer Soil tilth Tilt angle Position controlSide draft Tillage Disc angle Nozzle (in sprayers)Plow Primary tillage Spray angle Knapsack sprayerHarrow Secondary tillage Boom sprayer PulleyWeight transfer on Tractors

PTO horsepower Drill planter Angle of wrap

Compression ignition Engine

Indicated horsepower

Transplanter Sprocket

Engine displacement Rated horsepower Broadcaster Lug wheelCombine harvester Soil structure Pneumatic seeder FarmerField capacity Scouring Flat broken land LandBedded or listed land True line of draft Brake horsepower Drawbar

horsepower

Farm mechanization

1. Why is mechanization necessary? To increase labor efficiency and capacity To achieve timely operation (due to limited turn around time) To offset the problem of labor scarcity To minimize the drudgery of farm operation To attain quality products.

2. What are the advantages and disadvantages of mechanization? Increases labor efficiency Enables timely farming operation Reduce the drudgery of farm operations Increase safety of laborers Elevates the social status of the workers/farmers Displaces labor in some areas Require additional fixed investment

3. What are the current concerns in agricultural mechanization? Sustainability of the resource base Undesirable effect of machines such as soil compaction Gender issues in mechanization Contribution of machine emission to global warming

4. What are the current and emerging farm mechanization technologies? Application of geographical information system (GIS) in monitoring the

resource base Precision farming-maximum use of inputs such as fertilizers/chemicals Computer-controlled farming operations (such as remote-controlled

tractors and chemical sprayers) Application of robotics to high risk or hazardous farming operations

PLANTING EQUIPMENT

Definition: Planting Equipment –is any device used to place seed, seed pieces, or plant parts in or on the soil for propagation and production of food, fiber, and feed crops. it could be manually, mechanically (engine), or remotely operated.

A. Classification of Planting Equipment1. Row-crop planters

a. Trailing1. drill2. hill-drop3. check-row

b. Front Tractor-mounted1. drill2. hill-drop3. check-row

c. Rear Tractor-mounted1. drill2. hill-drop3. check-row4. transplanters or planters

2. Broadcast Cropa. Endgate seedersb. Narrow-and wide-tract and weeder-mulcherc. Airplanes

3. Grain Drills4. Planting attachments for other equipment

B. Row-crop Planters

1. Definition of Terms:a. Row-crop planters – planters designed and constructed to plant

seeds in rows far enough apart to permit cultivation of the crop.b. Transplanter – equipment for placing growing plants or plant parts

in the soil.c. Lister Planters – are drill planters designed to plant corn in listed

furrows.d. Drill planers – are row-crop planters designed to deposit seeds

continuously in straight columns.e. Hill-drop planters – row-crop planters designed to deposit one or

more seeds in a hill in equal intervals.f. Check-row – crop-crop planters equipped with valves, checkheads

and wire. Enable operator to perform hill planting at definite spacing (in checks or squares) which facilitates mechanical weed control and other operations.

2. Parts and Accessories for Corn Planters:a. Cutoff pawl – acting under spring pressure pushes the extra kernels

back at the cell under the plate cover.b. Knockout pawl – under spring pressure comes in contact with the

kernel, knocking through the cell into the seed tube, where it is allowed to fall either upon the valve if checking or directly into the soil if drilling.

c. Seed plates – used for planting corn.1. Edge drop – carries the kernel of corn on edge in the cell plate.2. Flat drop – carries the kernels flat in the cell of the plate.3. Full-hill plate – consist of cells around the outer edge large

enough to admit several kernels at the same time.d. Types of furrow openers

1. curve runner – generally used.2. Stub runner – is suited to rough and stony ground.3. Single-disk furrow opener4. Double-disk furrow opener

e. Covering attachments – covers the seedsf. Row marker – used to keep the rows straight, parallel and of equal

distance apart. It is intended for the machine operator as a guide.

C. Broadcast and Drill Planters:1. Types of machine broadcasters

a. knapsackb. endgatec. tow-wheeld. weeder-mulchere. airplane

2. The knapsack seeder is consists of a good-sized canvas sack fastened to a seeding mechanism, the whole being slung over the shoulders. A crank turned by hand revolves a wheel having several different radial ribs for scattering the seeds. The ribs throw the seeds out to the font and sides in a steady stream. A sliding gate regulates the quantity of seeds. Wider gate opening result in higher seed density (seed per unit area).

3. The tow-wheel drawn planter makes use of fluted wheels in sowing seeds.

4. The weeder-mulcher drops seeds on the ground and then covers them by means of a long spring-steel mulcher finges.

5. Grain drills are planters designed and built to place the seed of small grains and grasses in the ground in narrow-spaced rows at a uniform depth.

CULTIVATION AND CROP PROTECTION EQUIPMENT

A. Four general methods of controlling weeds, insects and plant diseases.1. mechanical cultivation or weeding.2. selective burning or flaming3. chemical application through spraying4. manual weed control5. flooding

B. Factors influencing the selection of weed control method:1. type and age of crop2. type and size of the weeds or grasses3. timeliness4. equipment available

C. Mechanical Cultivation

1. Mechanical Cultivation – farm operation using appropriate tool to stir the surface of the soil to a shallow depth to destroy young weeds and promotes crop growth.

2. Cultivation may control weeds in three ways:a uprooting the weedsb. cutting off the stem of the weeds just below the ground surfacec. Smoothering the aerial parts of the weeds by covering with soil.

3. Mechanical row-crop cultivators may be classified according to their attachment to the tractor.a. front-mountedb. rear-mountedc. side-mounted

4. Factors influencing the selection of cultivating tools.a. type and size of crop plantsb. soil type and field conditionc. purposes for which cultivation is being performed

5. Tools for cultivationa. sweeps (full or half)b. furrowersc. weed knives or beat hoesd. shovels (double-point, single-point, hoof shovel or spearheads)e. rotational blades (I-shaped, rectangular blades)

6. Cultivator attachmentsa. Rotary hoe – they are run directly over the rows and are used for

breaking, the soil crust over seedling and for destroying the weeds in the early stages of plant growth. They also acts as sailed and they allow sweeps to work at high speeds without covering even when the plants are small.

b. Rolling cultivators – it has twisted blades, which have slicing action that moves the soil laterally as well as uprooting small weeds and mulching the soil.

c. Fertilizer attachmentsd. Shield attachments – used in closed cultivation to prevent covering

of the plants with dirt or clods.e. Disk-hilling and barring-off attachments – for hilling, the disk are set

to throw the soil to the plant row. Where the crop is quite grassy, the disk are set to throw the soil away from the plant.

f. Knife attachment – it is used as barring-off tool, but it does not leave an open furrow as do the disks.

g. Stabilizer – these are rigid disk plates found on both sides of the frame of cultivating implement. They absorbed the side forces exerted by the soil forces thus stabilizing the implement during the operation.

7. Cultivator adjustments:a. relative horizontal position

b. depthc. pitch directional adjustments

8. Protective devices for cultivator standards – the purpose is to provide overload protection in case the tool encounters a stone, root or other solid objects.a. spring-trip mechanismb. friction-release

D. Flame WeedingThe theory of selective weeding is that the heat intensity and the exposure time are adjusted so enough heat is applied to the weeds and grasses to cause expansion of the liquid in the plant cells and consequent rapture of the cell wells but not enough heat to cause actual combustion. This method of weed control is usually applied during the stages of growth of the crop in which it can already withstand the heat. The forward speed of operation ranges from 3 to 4 mph.

E. Spraying1. The primary function of the sprayer – is to break the liquid into

droplets of effective size and distribute them uniformly over the surface or space to be protected and regulate the amount of chemical solution to avoid excessive application that might prove harmful or wasteful.

2. Spray particle size is significant in relation to:a. penetration and carrying ability obtained with hydraulic sprayersb. efficiency of catch of sprays or dusts by plant surfacesc. uniformly and completeness coveraged. effectiveness of individual particles after depositione. drift- is essentially a function of the rate of fall of particles in

relation to the horizontal velocity, which is related to particle size and local climatology.

3. Recommended methods to prevent or reduce drift:a. avoid high setting of nozzleb. careful selection of nozzle size and working pressurec. avoid spraying during unfavorable condition

4. Metering system for liquid sprayers:a. constant speed, constant head pump-orifice systemb. compressed air orifice systemc. gravity flow systemd. displacement ground-driven metering system

5. Types of sprayersa. Hand Sprayers

1. compressed-air sprayers2. knapsack sprayers

b. Power sprayers

1. hydraulic sprayers or field sprayers2. hydro-pneumatic sprayers3. blower sprayers

c. Hydraulic sprayers – make use of pumps to build up spray pressure of the spray solution.1. Classification of hydraulic sprayers

a. boom-type field sprayers with maximum operating pressure of 40 to 100 psi

b. high pressure, general purpose or orchard sprayers with maximum operating pressure ranging from 250 to 800 psi but mostly 400 to 800 psi

2. Basic components of hydraulic sprayer.a. tankb. agitatorc. framework for mounting the sprayerd. pressure regulatore. relief valvef. pressure gaugeg. strainer and screenh. control valvesi. pipes and fittingsj. boom and nozzlesk. pump

3. Pumps used in hydraulic sprayersa. Positive displacement pumps – those types where only a

small amount of liquid leaks past the actuator and it can only develop very high pressure (e.g. reciprocating pumps, diaphragm pumps, gear pumps).

b. Non-positive displacement pumps –those that are unable to develop more than 50 psi as used on farm sprayers (e.g., rotary pumps with flexible impeller, centrifugal pumps).

4. Rotary pumps – they are used for low pressure spraying. They are mounted on the tractor PTO shaft. They have a capacity of about 20-rpm. Their use is literally limited to sediment-free types of spray materials.

5. Centrifugal pumps – these pumps employ centrifugal force to lift liquids from a lower to a higher level. Because of their simplicity, low cost, and ability to operate under wide variety of conditions, they are one of the most popular types. They are adapted to operate under practically any head up to several thousand feet, will handle liquids at most any temperature up top 1000oF.

6. Agitators – used to keep the spray solution uniform. It can be either mechanical or hydraulic agitators.

7. Air chamber – used to cushion the discharge-pressure fluctuations, induce a uniform flow in sprayers using reciprocating and diaphragm pumps.

8. Pressure gage – used to guide the operator in adjusting the working pressure, located at the discharge line.

9. Pressure regulators – used to control and adjust the working pressure on the nozzles. They also serve as protective device in automatically unloading the excess pressure when the discharge line is closed.

10. Spray boom and nozzlesa. Boom – is a pipe on which the nozzles are properly spaced

and mounted.b. Nozzles – are used to direct the liquid in a thin film or stream

which will break up in a droplets.11. Parts of Nozzles

a. body d. washer and whirl plateb. cap e. strainerc. orifice plates

12. Types of hydraulic nozzlesa. hallow-cone (side-entry or cone insert) – the liquid is fed into

a whirl chamber through a tangential side entry passage or trough the spiral passage in a whirl plate or core insert to give it a rotary velocity component. The orifice is located on the axis of the whirl chamber and the liquid emerges in the form of a hallow conical shoot which then breaks up into droplets.

b. disk-type solid-cone- is the same as that of a hallow-cone nozzle except or the addition of an internal axial orifice. The axial stream is atomized and fills in the central section of the hallow-cone pattern.

c. Fan-spray nozzle – has a narrow, elliptical orifice formed by the intersection of a slot drilled across the face and semi-spherical surface cut out from the inside. The liquid emerges as a flat shaped sheet, which is then broken up into droplets.

d. Flooding nozzles – is commonly used as agricultural sprayers because of wider spray angle and atomization even at a low pressure, unlike hydraulic nozzles.

13. Liquid atomizationa. pressure or hydraulic atomizationb. gas atomizationc. centrifugal atomization

14. Factors affecting uniformity of distribution:a. nozzle sizeb. pressure on the spray solutionc. nozzle spacingd. boom heighte. speed of travel

15. The proper height of the boom above the deposition surface is a function of:

a. nozzle spacingb. nozzle spray anglec. amount of overlap required for uniform coverage, as

determined by the nozzle spray pattern.

TILLAGE

A. Objective of Tillage:1. to develop proper soil tilth2. to conserve soil and water3. to effect control of some pests and diseases4. to mix crop residues and fertilizers with the soil5. to control weeds6. to aerate the soil

B. Tillage Operation:1. primary tillage2. secondary tillage3. rotavation

C. Tillage Equipment1. Primary tillage equipment

a. Moldboard plow 1. share – cuts the furrow slice and partially lifts it

2. moldboard – breaking and inverting unit. Shin – the cutting edge of the moldboard, just above the landslide.

3. Landside – stabilizer to make the plow run in straight path counteracting the side pressure, exerted by the furrow slice on the moldboard.

b. Moldboard plow accessories1. Rolling colters – are round, flat sharpened steel disks, either

smooth or notch used to cut the furrow slice from the land and leave a clean wall.

2. Jointer – a miniature plow ahead of the plow bottom used to cut a narrow-shallow furrow slice- from the left upper side of the furrow in such a way that complete coverage by the main plow is initiated.

3. Weed hooks – rods attached to the plow beam used to bend tall weeds in order to have a thorough weed coverage.

4. Concave rolling disk colter – turns and cuts a shallow furrow slice.5. Spring – trip standard/hydraulic automatic reset standard –

allows the plow to move reaward when it meets an obstruction during the field operation.

c. Disc plow – it is a perfectly round, concave disk of heat-hardened steel, sharpened on the edge to aid in the penetration of the soil.1. Accessories of the disk plow

a. rear furrow wheel – it serves in counteracting the side thrust due to the soil pressure

b. scraper – set with cash disc to clear the disc of sticky soil and to assist in inverting the furrow slice.

2. Secondary Tillage Equipmenta. Disk harrows

1. Single-action disk harrows – consist of two gangs of disc placed end to end, which throw the soil in the opposite direction.

2. Double-action harrow – another set of two gangs plow behind the single action harrow and is arranged so that the disc on the front gangs throw the soil in the outward direction and the disc on the rear gangs throw the soil I the opposite direction.

3. Offset disc harrows – consists of two gangs, one is located behind the other.

b. Spike and spring tooth harrowsc. Chisel type – a tool with a rigid curved on straight shank with a

relatively narrow shovel point, usually arranged in staggered rows. It is usually used to break through or shatter compact or otherwise impermeable soil and to improve rainfall penetration. It is also used for stubble-mulch or subsurface tillage.

d. Subsoiler – these are tillage equipment heavier and larger than the chisel plow use to penetrate the soil to a depth form 20 to 36 inches. Form a tunnel at the subsoil to serve as drainage channel for water.

e. Middle breaker or lister – these are left and right-hand moldboard plow joined together. They are used to make furrows and to reshape the field after heavy downpour.

3. Draft Requirement a. Factors affecting draft of a plow

1. type and shape of bottom2. sharpness of the cutting tool3. over-all adjustments of the plow4. depth and width of cut of the furrow5. speed at which the plow is operated6. type of soil

b. Effect of soil moisture on tillage operation1. Effect of too dry soil

a. increases the rate of wear of the implementb. increases the power requirementsc. increases likelihood of implement breakage

2. Effect of too wet soila. increases the power requirementb. reduces the work output of the machinec. increases the total time for operationd. promote soil compaction

The correct moisture content is at a level of between 50% to 75% of field capacity.

4. Advantages of Tillage-Equipment:a. Moldboard plow – it eliminate back furrows and dead furrows leaving

the field more nearly leveled for irrigation and drainage.b. Disk plow – it is suitable for sticky, waxy, non-scouring soils and soils

having a hard pan. It is also suitable for dry, hard, rough, stony and rooty ground.

c. Rotary plow – effective for mixing chemical into the soil and for cultivation in certain row crops. Also good for cutting up vegetative matter and mixing throughout the tilled layer.

d. Chisel plow – effective in loosening hard and dry soil before the regular plow is used.

e. Subsoil plow – effective in penetrating the soil to depth from 20-36 inches, effective in opening and breaking up compacter soils in order that water nay seep into the opened spaces and stored.

f. Harrow – effective in leveling the round and crushing the clods, striving the soil and preventing and destroying the weeds, effective in putting the seal in better tilt for the reception of seeds.

g. Roller – effective as a clod crusher, effective in preparing the seedbox by thoroughly pulverizing and forming the loose soil so that there will not be any large air spaces or pockets.

h. Pulverizer – effective in pulverizing an area between rows and for fieldwork rather than or row work.

i. Mulchers – a combination of pulverizing equipment and harrow spring teeth.

Types of Implements:1. Pull type or trailed implement – is one that is pulled and guided from a

single hitch point and is never completely supported by the tractor.2. Mounted implement – is one that is attached to the tractor through a hitch

linkage in such a manner that it is completely supported by the tractor when in the raised position. The linkage usually provides rotational stability about the longitudinal axis and it permits depth or height control by vertical support from the tractor, if desired, while the tool is in the operating position.

3. Semi-mounted implement – is attached to the tractor through a horizontal or nearly horizontal axis and is partially supported by the tractor, at least during transport, but is never completely supported by the tractor. In the

usual situation then hinge axis is traverse at the near of the tractor and the hitch provides rotational stability about the longitudinal axis. The implement may respond directly to tractor steering, but if a vertical hinge axis is superimposed on the horizontal axis (as on large, semi-mounted plows), the rear of the implement is guided by its own wheels.

4. Self-propelled machine – is one in which the propelling power units is an integral part of the implement.

Factor Affecting Field Capacity of a tillage machine:1. time efficiency2. width of cut3. speed of travel

Difference between Traction Efficiency and Coefficient of Traction?

Coefficient of Traction – defined as the ratio of the tractor drawbar pull to the dynamic load on the traction device. Some of the factors which affect the coefficient of traction are types of traction device, tire inflation, soil type and state, soil moisture content, lug design, dimension of tractor device, and soil pressure distribution. Furthermore, it refers of the ratio of forces.

Traction Efficiency – refers to the conversion of energy. It can be defined as the ratio of the drawbar power to axle power. It is also a measure of the efficiency with which the traction device transforms the torque of the axle into a linear drawbar pull. Traction efficiency can be decreased by factors such as steering, rolling resistance, slip, friction, and deflection of the traction device.

Factors to be considered in designing and analyzing a system for mounting implements:

1. Ease of attachment and adjustment, versatility, and safety.2. Standardization to permit interchangeability.3. Uniformity of tillage depth as the tractor passed over ground-surface

irregularities.4. Ability to obtain penetration of the implement under adverse conditions,

particularly with implement such as disc harrows and disc plows.5. Rapidly with which the tools such as plows and lister enters the ground.6. Effect of the implement upon the tractive ability of the tractor (transfer

weight)7. Effect of the raised implement upon the transport stability of the tractor.

PLANTERS

A. Methods of Direct Seeding:1. Broadcasting – random scattering of seeds over the surface of the

field.2. Drill seeding – random dropping and covering of seeds in furrows to

give definite rows3. Precision planting – planting of single seeds at about equal intervals in

rows.4. Hill dropping –placing group of seeds at about equal intervals in rows.5. Minimum tillage planting – lister planting, till-and-plant combinations

following plowing or other primary tillage.

B. Function of a seed planter:1. Open the seed furrow to the proper depth2. Meter the seed3. Deposit the seed in the furrow in an acceptable pattern.4. Lower the seed and compact the soil around the seed to the proper

degree for the type of crop involved.

FARM MECHANIZATION INFOS

1. Methods of rice crop establishmenta. direct seeding or “sabog tanim”b. transplanting

NOTES:

Rice is transplanted for the pet and weed control purposes. The golden snail no longer eats a 20-day old rice seedling.

A transplanted rice plant have a head start over the weeds and with proper management can develop canopy and eventually outgrow the weeds.

Direct seeding has the advantage of reducing labor requirements and cost. However the rice seeds are exposed to pests such as birds, rats, and could be eaten by the golden snails as it germinates. Normally weed control is difficult thus forcing farmers to use herbicides.

2. 4 major rice ecosystems:a. irrigated or lowland ecosystem – with irrigationb. rainfed lowland ecosystem – depend on the rain for irrigationc. upland ecosystemd. flood-prone rice ecosystem

3. Precision Farming – a modern farming technique to attain optimum output or yield with minimum input possible utilizing geographical information

system (GIS), data base, and decision support system with the aid of computers.

4. Sustainable farming system – farming practice aimed to increase productivity while preserving the natural resources for future generations.

5. Organic farming – a sustainable farming system that seeks to eliminate the use of chemicals (fertilizers, pesticides, herbicides etc.) to avoid hazardous residues.

6. Integrated pest management (IPM) – part of the sustainable farming system that seeks to minimize and eliminate the use of pesticides in controlling pests. It is based on the principle that some insect pest are actually beneficial to the crop as they biological control other harmful organisms, and that harmful organisms are only destructive when they reach the critical level. It is only at this time that the chemical control must be used.

7. Crop simulation and modeling – first put into use by engineers to simulate and test the behavior of new design concepts such as airplanes in wind tunnels. Simulation and modeling is now being used by crop and other scientist to study and predict crop yields as affected by environmental forces, soil properties pest and diseases, etc.

8. Robots/Robotics – been intensively used in car manufacturing assembly lines to the jobs, which are routine and hazardous to human workers such as painting, spot welding, etc. It is now being used in agricultural production such as remote controlled tractors, sprayers, etc. It’s a substitute to humans in highly hazardous jobs. It is predicted that in the future robots will also work as house helpers to cook foods, prepare coffee, clean the comfort rooms, etc.

9. Global warming – a universal concern of increasing temperature attribute to ozone destruction due to methane emission, etc.

10. Transgenic rice – a genetically engineered rice where in good varietal traits will be integrated such as high yield, disease resistance, etc.

11. Dead furrow – the canal or trench formed by plowing away from the furrow in both directions.

12. Headland – strip of untilled land at the end of a field.13. Draft control – hydraulic implement hitch system that maintains a

constant draft o the implement.14. Combine harvester – a self-propelled farm machine that harvest,

thresh, and clean a grain crop.15. Factor of safety – the excess amount of material’s strength designed

into a machine so that it will not break down even beyond normal load.16. Automatic draft control – automatically raisers or lowers a soil-

engaging implement to maintain the draft at a pre-determined value.17. Dynamometer – an instrument used to measure horsepower.18. Side draft – the lateral or sideward force acting on a soil-engaging

implement such as plow.19. Universal joint – a mechanism used to transit power between two

intersecting shafts, where the angle between them is variable.

20. What are the advantages and disadvantages of using a chain and sprocket transmission in agricultural equipment?

Advantages:1. It’s relatively lightweight compared to gear transmission system.2. It’s cheaper.3. It’s easy to repair and maintain.4. Has no slippage compared to belt and pulley transmission system.

Disadvantages:1. It’s noisy2. It cannot operate well if there is excessive misalignment.

Farm work classification based on movement:

A. Tractive Work1. Land Preparation

a. plowingb. harrowingc. leveling

2. Cultivation3. Harvesting

B. Stationary Work1. Threshing2. Irrigation pumping3. Feed grinding4. Transportation/hauling

TILLAGE AND TILLAGE EQUIPMENT

Definition of Terms:

1. Tillage – is the mechanical manipulation of the soil from a known condition into a different desired condition.

2. Tilth – the physical condition of the soil in relation to plant growth.3. Soil structure – is the physical constitution of the soil material is

expressed by size, shaped and arrangements of the solid particles and associated voids to form the compound particles and the compound particles themselves.

4. Field capacity – is the moisture content of the soil after it has been saturated and allowed to drain for 24 to 72 hours.

5. Land – the unplowed soil.

6. Headland – unplowed soil at the end of the furrow strip.7. Furrow slice – is the ribbon of soil cut, lifted, pulverized and thrown to one

side of the plow bottom.8. Back furrow – is the raised ridge formed when a furrow slice is lapped

over another slice. This ridge is slightly higher that the other ridges.9. Dead furrow – is the open trench, about twice the width of one bottom,

formed when two adjacent furrow slices are thrown opposite each other.10. Furrow – is the trench/left when the plow bottom cuts and turns the

furrow slice.11. Furrow wall - is the unbroken side of the furrow.12. Scouring – is defined as the soil sliding freely over the surface of the

plow bottom.13. Primary tillage – is the initial breaking of the soil.14. Secondary tillage – is the further breaking of the soil following primary

tillage operation.15. Flat broken land – land broken by continuous lapping of furrows.16. Bedded or listed land – land broken in alternative back furrows and

dead furrows.17. True line of draft – is the line passing from the center of resistance

through the hitch point and to the center of pull.18. Indicated horsepower (IHP) – is the power generated in the cylinder

and received by the piston.19. Brake horsepower (BHP) – is the power delivered by the engine

crankshaft.20. Drawbar horsepower (DHP) – is the power developed at the hitch or

drawbar and available for pilling dragging or similar tractive effort.21. PTO horsepower – is the power developed at the power-take-off (PTO)

shaft of the tractor.22. Rated horsepower – is the amount of power that the engine will

generate at some designated crankshaft speed or it may be designated as a certain percentage of the maximum power output.

SAMPLE QUESTIONS:

1. Differentiate:a. draft control from position controlb. down suction from side suctionc. tilt angle from disc angled. sod type moldboard from stubble type moldboard

2. Explain and illustrate how the height of the nozzle in a boom hydraulic sprayer affects spray distribution (uniformity)

3. Give an advantage of one over the other.a. moldboard plow vs disc plowb. moldboard plow vs chisel plow

c. disc harrow vs rotary tillerd. two-way plow vs one-way plow

4. A cooperative of sugarcane farmers with a total land holding of 300 hectares wants to mechanize all the field operations except harvesting. Design a mechanization plan and determine the machinery requirement.

5. A corn planter meters seed as follows:single seed - 50%two seeds - 35%three seeds- 15%

If the row spacing is 75 cm and hill spacing is 25 cm, calculate the number of seeds needed for one hectare. If the effective ground wheel diameter is 75 cm and slippage is 5% determine the speed ratio of ground wheel to seed metering device if the seed plate has 20 cells.

5. A fertilizer recommendation is 60 kg per hectare. The row spacing is 1.25 m. If ammonium sulfate is to be used, determine the fertilizer material needed.

6. A lime spreader has a 10 m effective swath. If the tractor forward speed is 5 kph and the lime application rate is 5 tons per hectare, determine the discharge rate in kg/min.

7. What are the advantages and disadvantages of minimum tillage? Give at least two of each and explain why.

8. A carabao weighing 2,000 pounds is traveling 1,500 m/h t an instant. It is pulling a plow whose width of cut is 10 inches and depth of cut is 15 centimeters. How many horsepower is generated by the carabao at this condition if the ddraft is b kg/m2?

9. In problem 9, if the carabao weighs 950 kg, what will be the horsepower generated under the same condition?

10. If the draft in problem 9 is 0.9 b kg/m2, what should be the traveling speed to maintain the same horsepower?

11. In problem 10, if the depth of cut is reduced by 20%, should you increase or decrease the traveling speed to maintain the same horsepower?

12. Give at least 10 agricultural machines/implements and define their function and explain under what field condition they are applicable.

13. In a field demonstration of a rice reaper with a 1.2 m outer bar, the following performance data were recorded:

Average speed of travel ------------------------------- 3 kphAverage width of cutter bar actually utilized ---- 1.0 m

Time lost: Crossing dikes ------------------------------------------ 5 min/ha

Repair of broken belt ---------------------------------- 10 min/ha

Turning and other idle travel ----------- 10% of effective operating time Removing field obstructions and clogging ------ 15 min/ha

14. A newly purchased grain drill for upland rice production is to be calibrated to determine appropriate operating speed and seeding rate. The drill has 10 furrow openers spaced 25 cm apart and is equipped with pneumatic tires. When the grain hopper is filled at half its capacity and the tires are inflated at recommended pressure, the loaded radius is measured at 38 cm.

a. If the wheels are turned at the rate of 60 rpm, what is the equivalent ground speed of the machine, in kph, assuming an average wheel slippage of 15%?

b. Calculate the area covered by the drill, in ha, if the wheels were turned 600 times.

c. After turning the wheels at 60 rpm for 10 minutes, 13.4 kg of palay were collected from the seed tubes. What is the seeding rate of the drill, in cavans per hectare, under the given conditions? Assume 44 kg/cavan.

15. An engine rated at 2000 rpm will be used to operate a thresher, which has to run at 600 rpm. If the engine’s drive pulley has a pitch diameter of 8 cm., what diameter pulley should be installed on the main drive shaft of the thresher?

16. If the thresher has a cleaning fan that should run at 800 rpm and will be driven by the main drive shaft of the thresher, recommend the appropriate drive and driven pulley diameters.

17. Describe Position Control and Draft Control in a tractor hydraulic hitch system.

18. Explain “weight transfer” in a farm tractor hitch system and how it improves field efficiency. If necessary, make a schematic drawing of the tractor and implement and indicate the concept with arrows.

19. A farmer uses a carabao and a moldboard plow with a width of cut of 13 cm. to till his rice fields. If he overlaps each pass of the plow by twenty percent (20%), how many kilometers does he have to walk behind the carabao to plow one hectare?

If his average walking speed in the rice field is 3 kph, how long will it take him to plow one hectare (without rest)?

20. What are the advantages and disadvantages of using hydraulic systems for transmitting power in farm tractors, implements and other agricultural equipment?

21. Give three (3) reasons why farmers plow and harrow their fields before planting.

22. Defend farm mechanization against the labor displacement issue.

23. What is farm mechanization inappropriate?

24. What is gender issue in farm mechanization?

PRACTICE TEST #1

1. A compression ignition engine is also known as:a. gasoline engine b. stem engine c. diesel engine d. electronic ignition

2. Juan will plow a field 120 m wide and 426.4 feet long using a carabao and moldboard plow with a 10-inch width of cut. If his speed of plowing is 2 miles per hour, how long will he finish plowing if he plows along the length of the field with no headland left unplowed?a. 18.5 hrs b. 19.06 hrs. c. 20 hrs d. 20.5 hrs

3. How long will he finish plowing (#2) if he plows along the width of the field (with 2m headlands unplowed)?a. 18.40 hrs. b. 18.75 hrs. c. 18.95 hrs d. 19.00 hrs.

4. In problem #2, what is his plowing capacity (ha/hr)?a. 0.07 b. 0.075 c. 0.082 d. 0.090

5. In problem # 3, what is his plowing capacity (ha/hr)?a. 0.082 b. 0.085 c. 0.088 d. 0.090

6. In problem #2, if his plowing speed is 2 kph, how long will he finish plowing if he plows along the length of the field with no headlands left unplowed?a. 30.70 hrs. b. 30.75 hrs. c. 30.90 hrs. d. 31.00 hrs.

7. In accordance with condition in problem #6, how long will he finish plowing if he plows along the width of the field with no headlands left unplowed?a. 30.70 hrs. b. 30.75 hrs. c. 30.90 hrs. d. 31.00 hrs.

8. What is the plowing capacity (ha/hr) in problem # 6?a. 0.045 b. 0.051 c. 0.055 d. 0.06

9. What is the plowing capacity (ha/hr) in problem # 7?a. 0.051 b. 0.055 c. 0.06 d. 0.065

10. If the width of cut of his plow is 30 cm, by how much will his plowing capacity (ha/hr) increase in accordance with the conditions in problem #3?a. 0.012 b. 0.015 c. 0.018 d. 0.020

SAMPLE PROBLEMS

Problem 1:

A 1000 kg carabao traveling at v kph is pulling a moldboard plow whose width of cut is w centimeter at a depth of d inches. If the soil draft is s kg/sq.cm.

1. What is the total pull (in lb) being exerted by the carabao?a. 2,000 d. 5.95 swdb. 5.85 swd e. 2,200c. 5.59 swd f. none of the above (nota)

2. At the given velocity, how long will it take to plow a rectangular field whose length is L meters and W meters wide? (in hrs.)a. lw/10 VW d. LW/10 vwb. Lw/10 vW e. all of the abovec. lW/10 Vw f. none of the above

3. If the weight of the carabao is increased to 1,500 kg by how many percent is the total pull exerted by the carabao increased?a. 50% d. 53.33%b. 33.33% e. 0%c. 30% f. cannot be determined

4. If each succeeding pass overlaps the previous pass by 10%, by how much longer will it take to plow the same field in no. 2?a. LW/90 vW d. Lw/90 vWb. LW/9 vw e. all of the abovec. Lw/9 vW f. none of the above

Problem 2:

A two-hectare ricefield whose length is twice its width is to be harvested by a stripper combine whose average speed will be 5 kph. Field sampling of the crop showed 0.60 kg paddy per sq. meter. If the combine was able to finish the area in two hours.

5. How wide is the swath of the combine?a. 2 m. d. 2.2 yardsb. 79 in. e. all of dthe abovec. 6.6 ft. f. nota

6. Based on field area sampling what will be the total yield of the 2-hectare field?a. 12,200 kg. d. 26,840 lbs.b. 423.288 oz. e. all of the abovec. 12,200 x 103 g. f. none of the above

Problem 3:

A 6-nozzle boom sprayer is mounted at the back of a four wheel-tractor. The nozzles are arranged 150 cm apart along the boom length. Each nozzle has a 60 degree spray angle. Each nozzle delivers k l/min.

7. At what height must the boom be raised, relative to the ground level, so that the spray from each nozzle does not overlap upon reaching the top of a rice plant canopy which is 50 cm tall?a. 108 cm d. 309.8 cm.b. 180 cm e. 136.6 cmc. 93.3 cm f. nota

8. What is the effective swath of the boom sprayer in number 7?a. 150 cm d. 900 cm.b. 750 cm e. 90 cm.c. 75 cm. f. nota

9. If the tractor travels at 5 kph with 95% field efficiency, what will be the spraying capacity (in ha/hr) under the conditions in no. 8?a. 4.25 d. 4.70b. 4.52 e. 4.75c. 4.28 f. nota

10. If each nozzle delivers one liter per minute, how many will the boom sprayer deliver per hectare under the conditions in no. 9?a. 84.11 li/ha d. 76.60 hi/hab. 84.71 li/ha e. 75.79 li/hac. 79.65 li/ha f. nota

REVIEW PROBLEMS:

1. A farmer uses a hand tractor with 20 cm moldboard plow. How many kilometers must he walk to plow one hectare? (Ans. 50 km)

2. If he overlaps each pass by 10% how many kilometers more will he have to walk to plow one hectare? (Ans. 5.56 km)

3. If his walking speed is 1.55 miles per hour, how long will it take him to plow in each case (in #1 and #2)? What will be his plowing capacity (ha/t) in each case? (Ans. Time case 1:20 hrs. case 2:22.22 hrs; plowing capacity case 1:0.05 ha/ha, case 2:0.045 ha/t.)

4. An engine at 2000 rpm is to drive a pump to run at 1000 rpm. The engine drive pulley is 15 cm in diameter and there is a 10% belt slippage. What should be the diameter of the pulley on the pump? (Ans. 27 cm)

5. A. How many hectares can be plowed in one hour by a tractor operating at 5 kph and is pulling 3 moldboard plows with a total width of cut of 160 cm at a depth of 14 cm? (Ans. 0.80 ha/h)

B. What is the total draft in kilogram pull if there is a draft of 0.45 kg/cm2? (Ans. 1008 kg)

C. How many hectares can be plowed in 3 hours if 8% of the time is spent on headland turning? (Ans. 2.208 ha)

6. A 2-hectare farm is to be planted by a 4-row rear mounted corn planter traveling 5 km/h with a row spacing of 1 meter. The field is twice as long as its width. If 3 minutes is spent for each head land turn:A. How many turns will the planter make to plant the whole area? (Ans.

24 turns)B. How many hours is needed to plant the whole field if the plant rows

runs along the longer length? (Ans. 2.2 hours)C. How many percent of the total planting time in (B) was spent in

headland turning? (Ans. 54.54%)D. If the planter delivered an average of 12 seeds per linear meter, how

many seeds are needed for the entire area including the headlands? Planting is along the longer side. (Ans. 240,000 seeds)

7. A sprayer is operating at 6 kph, covering 30 hectares in 6 hours 20% of the time was spent on headland turning and tank filing.A. What is the effective swat boom of the sprayer? (Ans. 10.42 meters)B. If the area is increased to 40 hectares, what should be the operating

speed to finish spraying in 6 hours with 20% time loss? (Ans. 8.0 kph)C. If the boom is 10 meters wide and delivers 25 liters/hour, what is the

application rate in l/ha in (A) and (B)? (Ans. In (A) 250 t/ha, (B) 187.5/ha)

8. A farmer will use an 8-row grain drill for planting paddy. Its ground wheel is one meter in diameter designed for slip operation. Row spacing is adjustable. He will follow a 100-kg/ha seeding rate recommendation.A. If the row spacing is 25 cm, how much paddy (in grams) must the drill

deliver for one revolution? (Ans. 62.8 grams)B. If 1000 seeds weighs 25 grams and assuming uniform distribution, how

many seeds must there be per linear meter along the row? (Ans. 100 seeds/m)

C. If the working speed is 5 km/h, how much time is needed to plant a square 2-hectare field at 20 cm row spacing? (Ans. 2.5 hours).

FERTILIZER PROBLEMS:

1. Find the amount of fertilizer materials needed for one hectare to satisfy the recommended application rate of 90 kg N, 60 kg P2O5, and 30 kg K2O per hectare.

Fertilizer Materials (FM): (Urea) 45-0-0(Superphosphaste) 0-20-0(Muriatic of potash) 0-0-60

(Ans. Urea: 200 kg:Superphosphate: 300 kg:Muriate of potash 50 kg)

2. Given the following commercial fertilizers:Complete 14-14-14

Ammophos 16-20-0Ammonium sulfate 20-0-0

Find the amount of each fertilizer material needed for 6,375 m2, if the recommended rate is 120+90+60? (Ans. Complete 273.2 kg. Ammophos 150 kg: Ammonium sulfate: 115.0 kg)

3. Given two fertilizer combination C1 and C2. Which is cheaper and by how much?C1: 16-20-0 (P350/bag) plus 20-0-0 (P268/bag)C2: 0-20-0 (P298/bag) plus 45-0-0 (P393/bag)