Lesson Notes By Weeks and Term v4 - SHS 1

Lesson Video

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Performance objectives

• Identify different types of agricultural machinery.
• Explain the functions and importance of each machine.
• Describe how machinery increases agricultural productivity.
• Discuss maintenance and safety measures for operating machinery.

Lesson summary

Welcome, students! Today, we are moving from the farm tools we know, like the cutlass and hoe, to the powerful machines that are changing the face of farming in Ghana and around the world. Think about the vast rice fields in the Volta Region or the large maize farms in the Afram Plains. Feeding our nation requires farming on a big scale, and this is where agricultural machinery becomes essential. This lesson will introduce you to the common machines that help farmers prepare land, plant seeds, and harvest crops more efficiently, making their work easier and more profitable. Understanding these machines is the first step to understanding modern, commercial agriculture.

Lesson notes

A. What is Agricultural Mechanization? Agricultural Mechanization is the use of machinery to replace human and animal power in farming operations. It involves using machines to do work like clearing land, ploughing, planting, weeding, harvesting, and processing crops. The main power source for most of these machines is the tractor.

Importance in Ghana: Increased Speed and Efficiency: A tractor with a plough can prepare a hectare of land in a few hours, a task that would take many people several days with hoes and cutlasses. Timeliness: Crops need to be planted at the right time to benefit from the rains. Machines ensure that large farms can be planted on time. Reduced Drudgery: Farming is hard physical work. Machines reduce the physical strain on farmers. Increased Productivity: Farmers can cultivate larger areas of land, leading to higher yields and more food for the country. This supports programmes like "Planting for Food and Jobs." B. The Tractor: The Prime Mover The tractor is the most important machine on a mechanized farm. It doesn't do the farming itself, but it provides the power to pull or operate other machines, which are called implements or attachments. It does this through: The Drawbar: A strong bar at the back to pull implements like ploughs and harrows. The Power Take-Off (PTO) Shaft: A rotating shaft at the rear that powers machines like sprayers and slashers. C. Classification of Farm Machinery by Function

We can group farm machinery based on the job they do on the farm. Tillage Implements (For Land Preparation) Tillage is the process of preparing the soil for planting. It is done in two main stages. i. Primary Tillage Implements: These are used for the first, deep, and rough digging of the soil. They break up hard, compacted land and bury weeds and crop residues. Mouldboard Plough: This plough has a curved plate (the mouldboard) that cuts, lifts, and completely turns over the soil slice. This is very good for burying weeds and is effective in loamy soils. Disc Plough: This plough uses a set of large, sharp, concave steel discs that rotate as they cut through the soil. It is better than the mouldboard plough for hard, dry, or stony soils and land with many tree stumps, as the discs can roll over obstacles.

*(Teacher to draw a simple diagram on the board showing the inverting action of a mouldboard vs. the cutting/rolling action of a disc plough)* ii. Secondary Tillage Implements: These are used after primary tillage to break up the large soil clods, level the surface, and create a fine seedbed suitable for planting. Harrows: Used to break soil clods and smooth the soil surface. The most common is the Disc Harrow, which uses smaller discs than a disc plough. Ridger: Used to create ridges and furrows. This is very common in Ghana for planting crops like yam, cassava, and maize. The ridges provide loose soil for tuber expansion and help with water management. Cultivator: Used for shallow tillage. It can be used for final seedbed preparation or, more commonly, for controlling weeds between rows of growing crops. Planting Machinery These machines are used for placing seeds or seedlings into the prepared soil. Planter / Seeder: Used for sowing seeds in rows at a specific depth and spacing. A maize planter, for example, will drop maize seeds one by one at the correct distance apart. Transplanter: A machine that plants young plants (seedlings) that have been grown in a nursery. This is common for crops like rice and tomatoes. Crop Maintenance Machinery These machines are used to care for the crops as they grow. Sprayer: Used to apply liquid chemicals like herbicides (to kill weeds), pesticides (to kill insects), and fertilizers. They can be boom sprayers (tractor-mounted with long arms) or smaller knapsack sprayers. Fertilizer Spreader: Used to apply solid, granular fertilizers evenly over a large area. Harvesting Machinery These machines are used to gather the mature crops from the field. Combine Harvester: A complex machine that combines three operations in one: reaping (cutting the crop), threshing (separating the grain from the stalk), and winnowing (cleaning the grain). It is used for grain crops like rice, maize, and soya beans. Root Crop Harvester: Specialised machines for harvesting crops like potatoes, cassava, or yams by digging them out of the ground. Post-Harvest Machinery These machines are used after harvesting to process the crops and prepare them for storage or sale. Thresher / Sheller: Used to separate grains from the rest of the plant. A maize sheller, for example, removes the maize kernels from the cob. Dryer: Used to reduce the moisture content of grains to a safe level for storage, preventing spoilage.

Evaluation guide

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• �Subject AGRICULTURAL SCIENCE