Lesson Notes By Weeks and Term v4 - SHS 1

Lesson Video

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Performance objectives

• Identify different types of farm machinery.
• Explain the functions and benefits of these machines.
• Analyze their impact on farming efficiency.
• Perform basic calculations related to machinery use.
• Understand machinery maintenance and safety.

Lesson summary

This lesson introduces the essential topic of agricultural machinery, the engines of modern farming. For generations, Ghanaian farmers have relied on the cutlass and hoe. While effective, these tools limit the scale and speed of farming. As Ghana's population grows, we need to produce more food more efficiently. This is where agricultural machinery comes in. By understanding these machines, we can see how farming can be transformed from a labour-intensive activity into a modern, efficient, and profitable business, attracting more young people to the sector. This lesson will move us beyond simple tools to the powerful machines that shape modern agriculture in Ghana and around the world.

Lesson notes

A. What is Agricultural Machinery? Agricultural Machinery refers to the machines, with various moving parts, designed to carry out specific farming operations. They are typically powered by sources other than direct human muscle, such as animals or engines. Distinction from Farm Tools: A simple farm tool like a hoe or cutlass is powered directly by human energy. A machine, like a corn sheller or a tractor, uses mechanical advantage or an external power source to multiply the effort and get more work done. Example: One person using a hand-held sheller can shell several cobs of maize in the time it would take to shell one by hand. A tractor-powered sheller can do several bags in minutes. B. Classification of Agricultural Machinery We can group agricultural machines in two main ways: by how they are powered and by the job they do. Classification by Power Source: Human-powered Machinery: These use gears, levers, and cranks to make human effort more efficient. *Examples:* Hand-cranked corn sheller, manual push planter, knapsack sprayer. Animal-powered Machinery: These use the pulling power (draught force) of animals. Common in the savannah regions of Ghana. *Examples:* Bullock plough, donkey cart, ox-drawn cultivator. Engine-powered (Mechanical) Machinery: These are powered by internal combustion engines (using petrol or diesel) or electric motors. They are the most powerful and efficient. *Examples:* Tractors, combine harvesters, power tillers, water pumps for irrigation. Classification by Farm Operation: This is the most common way to classify machinery, based on the stage of production. i. Tillage Machinery (For Land Preparation): Primary Tillage: The first, deep ploughing of the soil. It breaks up hard, compacted soil and buries weeds. Mouldboard Plough: Cuts, lifts, and turns the soil over completely. Best for soft, loamy soils. Disc Plough: Uses large, rotating concave discs to cut through hard, dry, or stumpy soil. It is more suitable for many Ghanaian soils, especially during the dry season. Secondary Tillage: Operations that follow primary tillage to create a fine, level seedbed suitable for planting. Harrows (Disc Harrow, Spike-tooth Harrow): Break up large soil clods left by the plough. Rotavator/Rotary Tiller: Uses rotating blades to churn and mix the soil, creating a very fine tilth in one pass. Often used in vegetable and rice farming. ii. Planting Machinery: Planters: Sow large seeds like maize, beans, and groundnuts in rows at specific distances. Seed Drills: Sow small-grained seeds like rice or wheat in furrows at a controlled rate. Transplanters: Mechanically transplant seedlings (e.g., rice, tomato) from a nursery to the main field. iii. Crop Care and Maintenance Machinery: Sprayers: Apply liquids like herbicides, pesticides, or foliar fertilizers. *Knapsack Sprayer:* Carried on the back, common on small farms. *Boom Sprayer:* Attached to a tractor with a long boom (arm) to cover large areas quickly. Fertilizer Spreaders: Distribute granular fertilizers evenly over a field. iv. Harvesting Machinery: Combine Harvester: A revolutionary machine that *combines* three operations: reaping (cutting the crop), threshing (separating grain from the plant), and winnowing (cleaning the grain). Used for cereals like rice, maize, and soybeans. Mowers/Reapers: Cut forage crops or grains, leaving them in the field to be gathered later. Root Crop Harvesters: Machines designed to dig up crops like potatoes or cassava. v. Post-Harvest Machinery: Threshers: Separate grains from the harvested stalks (e.g., rice thresher). Shellers: Remove maize grains from the cob. Dryers: Use heat or forced air to reduce the moisture content of grains for safe storage. Grinding Mills: Process grains into flour or paste (e.g., corn mill, rice mill). C. Focus on a Key Machine: The Tractor The tractor is the most important and versatile machine on a modern farm. It is primarily a power source. Main Functions: To Pull Implements (Drawbar Work): It pulls ploughs, harrows, trailers, etc. To Power Implements (PTO Work): It has a Power Take-Off (PTO) shaft at the back. This rotating shaft transfers power from the tractor's engine to other machines like rotavators, sprayers, or shellers. To Lift Implements (Hydraulic System): A hydraulic lift system allows the tractor to raise and lower heavy implements like ploughs. Common Tractor Brands in Ghana: Massey Ferguson, John Deere, New Holland.

Guided Practice (With Solutions)

Question 1: Match the agricultural machine in Column A with its primary function in Column B.

| Column A | Column B | | --------------------- | --------------------------------------------- | | 1. Disc Plough | A. Sows small seeds like rice in rows | | 2. Combine Harvester | B. Applies pesticides to crops | | 3. Knapsack Sprayer | C. Performs primary tillage in hard, dry soil | | 4. Seed Drill | D. Reaps, threshes, and cleans grains |

Evaluation guide

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• �Subject AGRICULTURAL SCIENCE