Operation: Ploughing
Main Implement: Mouldboard Plough (Tractor-drawn or animal-drawn).
Practical Application:
o Set the plough to the correct depth (typically 15-30 cm for most annual crops).
o Ensure the furrows are straight and of uniform width to facilitate subsequent
operations.
o Invert the soil slice completely to effectively bury weeds and residues.
o Kenyan Example: Preparing land for maize planting in the high-potential
regions of the Rift Valley after harvesting wheat stubble.
B. Secondary Tillage Operations
These follow primary tillage to break large clods, level the surface, incorporate
fertilizers, and eliminate remaining weeds to create a fine tilth.
Operation 1: Harrowing
o Implements: Disc harrow, tine harrow, spike-tooth harrow.
o Practical Application: Pull the harrow across the ploughed field at a right
angle to the furrows. The discs or tines break clods, level the soil, and cut
weed roots. Multiple passes may be needed for a fine tilth.
Operation 2: Cultivation (Inter-row Tillage)
o Implements: Cultivator (with sweeps or tines), hand hoe (jembe).
o Practical Application: Performed after crop emergence to control weeds
between rows, aerate the soil, and break surface crusts. Depth is shallow to
avoid damaging crop roots.
o Kenyan Example: Weeding and aerating soil around young coffee plants in
Central Kenya using a hand hoe or a small tractor-mounted cultivator.
Operation 3: Ridging and Bed Making
o Implements: Ridger, bed former.
o Practical Application: Forming raised rows (ridges) or flat-topped beds to
improve drainage, facilitate irrigation (e.g., furrow irrigation), and provide
deep, loose soil for root crops.
o Kenyan Example: Creating ridges for potato cultivation in Nyandarua County
to prevent waterlogging and allow for easy tuber development.
3. Factors Influencing Choice of Tillage Operation
A competent farmer or farm manager must consider:
Soil Type: Heavy clay soils require more secondary tillage than sandy soils.
Climate & Season: Minimize tillage before heavy rains to reduce erosion
(Conservation Tillage principle).
, Crop to be Planted: Small-seeded crops (e.g., carrots, onions) require a finer
tilth than large-seeded crops (e.g., beans, maize).
Weed Pressure: Heavily infested land may require more intensive primary
and secondary tillage.
Available Resources: Scale of operation, availability of tractor, oxen, or hand
tools, and labour costs.
Moisture Content: Till when soil moisture is optimal (friable) – not too wet
(forms clods) and not too dry (hard to break).
4. Safety and Best Practices
Always inspect implements for loose bolts, broken parts, or worn blades
before use.
Use appropriate Personal Protective Equipment (PPE): sturdy boots, gloves,
and eye protection when operating machinery.
Ensure all PTO (Power Take-Off) shields on tractors are in place.
Clear the field of large stones and debris that could damage implements or
cause injury.
Follow correct hitching procedures for animal-drawn or tractor-drawn
implements.
1. Core Concept of Practical Maintenance
Practical Maintenance refers to the hands-on, applied activities performed to keep
equipment, machinery, systems, or facilities in proper working condition, prevent failure,
and restore functionality after a breakdown. It moves beyond theory to the actual doing,
emphasizing skill, procedure, safety, and correct tool use.
2. Key Types of Practical Maintenance
Understanding these categories guides the selection of the correct practical procedure.
A. Preventive (Scheduled) Maintenance
Proactive tasks performed at regular intervals to prevent equipment failure.
Key Activities: Lubrication, cleaning, calibration, tightening, inspection, part replacement based
on time/usage.
Practical Example (Automotive): Performing a 10,000 km service: changing engine oil and
filter, checking brake pads, rotating tyres, inspecting fluid levels.
Practical Example (Electrical): Quarterly inspection of industrial motor terminals for tightness
and signs of arcing, cleaning dust from control panels.
B. Corrective (Breakdown) Maintenance
Reactive tasks performed to correct a fault after it has occurred, to restore function.
Main Implement: Mouldboard Plough (Tractor-drawn or animal-drawn).
Practical Application:
o Set the plough to the correct depth (typically 15-30 cm for most annual crops).
o Ensure the furrows are straight and of uniform width to facilitate subsequent
operations.
o Invert the soil slice completely to effectively bury weeds and residues.
o Kenyan Example: Preparing land for maize planting in the high-potential
regions of the Rift Valley after harvesting wheat stubble.
B. Secondary Tillage Operations
These follow primary tillage to break large clods, level the surface, incorporate
fertilizers, and eliminate remaining weeds to create a fine tilth.
Operation 1: Harrowing
o Implements: Disc harrow, tine harrow, spike-tooth harrow.
o Practical Application: Pull the harrow across the ploughed field at a right
angle to the furrows. The discs or tines break clods, level the soil, and cut
weed roots. Multiple passes may be needed for a fine tilth.
Operation 2: Cultivation (Inter-row Tillage)
o Implements: Cultivator (with sweeps or tines), hand hoe (jembe).
o Practical Application: Performed after crop emergence to control weeds
between rows, aerate the soil, and break surface crusts. Depth is shallow to
avoid damaging crop roots.
o Kenyan Example: Weeding and aerating soil around young coffee plants in
Central Kenya using a hand hoe or a small tractor-mounted cultivator.
Operation 3: Ridging and Bed Making
o Implements: Ridger, bed former.
o Practical Application: Forming raised rows (ridges) or flat-topped beds to
improve drainage, facilitate irrigation (e.g., furrow irrigation), and provide
deep, loose soil for root crops.
o Kenyan Example: Creating ridges for potato cultivation in Nyandarua County
to prevent waterlogging and allow for easy tuber development.
3. Factors Influencing Choice of Tillage Operation
A competent farmer or farm manager must consider:
Soil Type: Heavy clay soils require more secondary tillage than sandy soils.
Climate & Season: Minimize tillage before heavy rains to reduce erosion
(Conservation Tillage principle).
, Crop to be Planted: Small-seeded crops (e.g., carrots, onions) require a finer
tilth than large-seeded crops (e.g., beans, maize).
Weed Pressure: Heavily infested land may require more intensive primary
and secondary tillage.
Available Resources: Scale of operation, availability of tractor, oxen, or hand
tools, and labour costs.
Moisture Content: Till when soil moisture is optimal (friable) – not too wet
(forms clods) and not too dry (hard to break).
4. Safety and Best Practices
Always inspect implements for loose bolts, broken parts, or worn blades
before use.
Use appropriate Personal Protective Equipment (PPE): sturdy boots, gloves,
and eye protection when operating machinery.
Ensure all PTO (Power Take-Off) shields on tractors are in place.
Clear the field of large stones and debris that could damage implements or
cause injury.
Follow correct hitching procedures for animal-drawn or tractor-drawn
implements.
1. Core Concept of Practical Maintenance
Practical Maintenance refers to the hands-on, applied activities performed to keep
equipment, machinery, systems, or facilities in proper working condition, prevent failure,
and restore functionality after a breakdown. It moves beyond theory to the actual doing,
emphasizing skill, procedure, safety, and correct tool use.
2. Key Types of Practical Maintenance
Understanding these categories guides the selection of the correct practical procedure.
A. Preventive (Scheduled) Maintenance
Proactive tasks performed at regular intervals to prevent equipment failure.
Key Activities: Lubrication, cleaning, calibration, tightening, inspection, part replacement based
on time/usage.
Practical Example (Automotive): Performing a 10,000 km service: changing engine oil and
filter, checking brake pads, rotating tyres, inspecting fluid levels.
Practical Example (Electrical): Quarterly inspection of industrial motor terminals for tightness
and signs of arcing, cleaning dust from control panels.
B. Corrective (Breakdown) Maintenance
Reactive tasks performed to correct a fault after it has occurred, to restore function.
