Lesson Notes By Weeks and Term v4 - SHS 1
AGRICULTURAL MACHINERIES
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AGRICULTURAL MACHINERIES
Download the Lessonotes Mobile Ghana app for faster lesson access on Android and iPhone.
Subject: Agricultural Science
Class: SHS 1
Term: 1st Term
Week: 7
Grade code: 1.1.3.LI.2
Strand code: 1
Sub-strand code: 3
Content standard code: 1.1.3.CS.1
Indicator code: 1.1.3.LI.2
Theme: NEW DAWN IN AGRICULTURE
Subtheme: AGRICULTURAL MACHINERIES
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In Ghana, many of our farmers depend on rainfall to grow their crops. This makes farming very risky, especially with changing weather patterns. When the rains fail, crops wither, and farmers lose their investment. Agricultural machinery, specifically modern irrigation systems, offers a powerful solution. By using machines to supply water to crops, farmers can cultivate their fields all year round, increase their harvest, and turn farming into a more predictable and profitable business. This lesson will introduce you to common irrigation machinery and, most importantly, teach you how to analyse whether investing in them is a good financial decision.
A. What is Irrigation? Irrigation is the artificial application of water to land or soil to assist in the growing of crops. It is used to supplement rainfall, especially during the dry season or in areas with low rainfall, like the Northern regions of Ghana. B. What is Irrigation Machinery? These are the tools and equipment used to move water from its source (like a river, dam, or borehole) to the farm and distribute it to the crops. We will focus on two modern and efficient systems. Sprinkler Irrigation System This system mimics natural rainfall. Water is pumped through a network of pipes and sprayed into the air through rotating sprinkler heads, falling onto the crops like rain. Key Components: Water Pump: The engine that draws water from the source and pushes it into the pipes. Can be powered by petrol, diesel, or electricity. Main Pipes & Sub-pipes: Larger pipes that carry water from the pump to the field, and smaller pipes that branch off to different sections. Sprinkler Heads/Nozzles: Devices that rotate and spray the water over the crops. Advantages: Covers a large area quickly. Suitable for a wide variety of crops, like maize, rice, and vegetables. Less labour-intensive than manual watering. Disadvantages: High water loss due to evaporation and wind drift. High initial cost for the pump and pipes. Can lead to fungal diseases if leaves remain wet for too long. Drip Irrigation System (or Trickle Irrigation) This is a highly efficient system that delivers water slowly and directly to the root zone of the plants. Key Components: Water Pump: To provide pressure. Filtration Unit: Crucial for removing dirt that could block the system. Mainlines, Sub-mains, and Laterals: A network of pipes that carry water across the farm. Emitters or Drippers: Small devices attached to the pipes that release water drop by drop near the plant's base. Advantages: Very High Water Efficiency: Minimal water is lost to evaporation (up to 95% efficiency). Reduces Weed Growth: Water is only supplied where the crop is, so weeds in between rows don't get water. Fertigation: Liquid fertilizer can be mixed with the irrigation water and delivered directly to the roots. Disadvantages: Very high initial installation cost. Emitters can easily get clogged if the water is not filtered properly. Pipes can be damaged by farm animals or during weeding. C. Analysing Profitability: The Core of the Lesson
To decide if buying an irrigation machine is a good idea, a farmer must analyse its profitability. Profitability is simply a measure of how much money you make after subtracting all your expenses.
The Basic Formula: Profit = Total Revenue - Total Cost Total Revenue: This is the total amount of money you get from selling your produce. `Total Revenue = Yield (in kg, bags, or pieces) × Price per Unit (GHS)` Irrigation significantly increases yield, which is the main way it boosts revenue. Total Cost: This is the total amount of money spent on the farm. It has two parts: Fixed Costs (or Capital Costs): These are one-time investment costs for equipment that lasts many years. Cost of the water pump Cost of pipes, sprinklers, or drip lines Cost of a water tank (e.g., Polytank) Cost of drilling a borehole (if needed) Installation labour cost Variable Costs (or Running Costs): These are costs you incur during the growing season. Fuel (petrol/diesel) or electricity to run the pump Cost of seeds, fertilizer, pesticides Labour for planting, weeding, and harvesting Maintenance and repair of the irrigation system