Fencing: Creating Boundaries and Protecting Your Farm
Hello future agriculturalists! We are diving into Chapter 10: Farm Structures and Tools. This section is super practical—it’s about building the physical foundations of a successful farm.
Our first topic, Fencing, might seem simple, but a poorly constructed fence can lead to huge losses (like livestock escaping or crops being destroyed by wandering animals). Here, we’ll learn how to build strong, long-lasting boundaries that protect your investments and improve your farm management.
10.1 Fencing Posts: Making Them Last
Fencing posts are the backbone of any fence. Since they are driven into the ground, they are constantly exposed to moisture, soil microorganisms, and pests (especially termites). If they rot quickly, your entire fence fails.
1. The Importance of Post Treatment
The main goal of post treatment is preservation—making the wood resistant to two main enemies:
- Rot (Decay): Caused by fungi and bacteria when wood is wet.
- Insect Damage: Primarily caused by termites, which eat the wood cellulose.
2. Methods for Treating Fencing Posts
There are several ways farmers treat wooden posts to prolong their lifespan, which is often called curing or preservation.
(a) Chemical Treatment
This is the most common and effective method for commercial durability.
- Process: Posts are soaked or pressurized with chemical preservatives.
- Examples of Chemicals: Creosote (a thick, oily substance often used for railway sleepers and boundary fences) and CCA (Copper Chromated Arsenate).
- Safety Note: CCA-treated wood is very durable but the chemicals are toxic. Always handle chemically treated posts wearing gloves and avoid using them near human food crops or water sources, as required by safety regulations.
(b) Charring (Burning)
This is a traditional, cheaper, and more environmentally friendly method.
- Process: The end of the post that will be placed in the ground is lightly burned until a thin layer of charcoal forms.
- Benefit: The charred layer acts as a barrier, making the wood less palatable to termites and reducing moisture absorption, thus slowing down decay.
(c) Using Naturally Durable Timber
If available, using wood that naturally resists rot and insects eliminates the need for extensive chemical treatment.
Did you know? Certain hardwoods, like Teak or specific species of Cypress, naturally contain oils and resins that repel insects and moisture, making them excellent choices for long-lasting posts.
Key Takeaway: Treating posts is crucial farm management that saves money and labour in the long run by preventing early fence collapse.
10.1 Fence Construction: Building a Strong Barrier
Building a fence isn't just about hammering posts into the ground; it requires careful planning and engineering to handle the immense tension of stretched wire.
1. Essential Components of a Wire Fence
- Corner Posts: Placed at the beginning, end, and all corners. These must be the strongest as they take the most strain.
- Strain/Tension Posts: Used along straight lines every 100–200 meters to allow wire to be tightened properly.
- Intermediate/Line Posts: Placed between strain posts to hold the wire off the ground and maintain spacing. They do not take significant tension.
- Struts/Stays: Diagonal wooden or metal supports placed between the corner/strain post and the ground, essential for stopping the post from leaning inward due to wire tension.
- Fencing Material: Usually wire (barbed, plain, or netting).
2. Step-by-Step Construction Method
Step 1: Planning and Measurement
Mark out the fence line using pegs and string. Measure the spacing accurately based on the type of wire and terrain.
Step 2: Installing Corner and Strain Posts
These posts must be deeply set (about one-third of the post below ground) and firmly compacted with soil, stones, or sometimes concrete.
Crucial step: Install the struts/stays immediately. The stay transfers the strain from the corner post into the ground, acting like a buttress on a wall. (Analogy: Think of the main anchor points on a suspension bridge—they need heavy support!)
Step 3: Installing Intermediate Posts
These are set at regular intervals (often 3–5 meters apart). They can be smaller and do not usually require struts.
Step 4: Running and Tensioning the Wire
This is where the fence gets its strength.
- Wires are attached loosely to the corner post.
- A wire stretcher or specialized tensioner is used to pull the wire taut before it is fastened to the subsequent posts.
- Why tension is key: A slack fence is useless. Tension ensures the fence holds its shape and provides the necessary physical barrier.
Step 5: Fastening the Wire
Wires are secured to wooden posts using fencing staples or to metal posts using specialized clips. Ensure the fastening is firm but allows the wire to move slightly in case of temperature changes.
Common Mistake to Avoid: Not properly bracing the corner posts. If the corner post pulls out of the ground, the entire fence line will collapse!
10.1 Types of Fences for Different Purposes
The type of fence you choose depends entirely on what you are fencing in or out. A fence suitable for cattle is not suitable for chickens.
1. Barbed Wire Fences
- Description: Wires with sharp barbs (spikes) at regular intervals.
- Purpose: Used primarily to contain or exclude large livestock like cattle and goats. The barbs act as a psychological deterrent—the animals learn to avoid touching it.
- Suitability: Excellent for boundaries and extensive grazing areas.
2. Plain Wire Fences (High-Tensile Wire)
- Description: Strong, smooth, high-strength steel wire, stretched extremely taut.
- Purpose: Used for large livestock where high strength is needed, especially in rotational grazing systems where fences must last a long time.
- Benefit: Needs fewer posts than barbed wire because it is stronger when highly tensioned.
3. Netting or Woven Wire Fences
- Description: Wire is woven into tight mesh patterns (like a basketball net).
- Purpose: Essential for fencing smaller animals such as poultry, sheep, pigs, or preventing predators (like jackals or wild dogs) from entering.
- Suitability: Provides a complete physical barrier that smaller animals cannot squeeze through.
4. Electric Fences
- Description: Wires carry pulses of high-voltage, low-amperage electricity.
- Purpose: Mainly used for rotational grazing (paddock grazing) and temporary boundaries. It is a psychological barrier, not a physical one.
- Benefit: Easy to install and move, making them ideal for intensively managed pastures. They teach animals respect for boundaries quickly.
Quick Review: Big animals = Barbed/High-tensile. Small animals/Predators = Netting. Temporary/Grazing management = Electric.
10.1 The Use of Hedges and Windbreaks
Fences don't always have to be made of wood and wire! Living plants can serve important structural roles on the farm.
1. Hedges (Living Fences)
A hedge is a line of closely planted shrubs or trees that forms a dense, living boundary.
- Benefits:
- They are cheaper in the long term than artificial fences.
- Provide shelter and shade for livestock.
- Can offer fodder (food) for certain types of livestock.
- Create habitats for beneficial insects and wildlife.
- Offer a strong physical barrier if thorny species (like certain acacia or cactus types) are used.
- Drawbacks: They take a long time to establish and require regular trimming (maintenance).
2. Windbreaks
A windbreak is a row or multiple rows of trees or large shrubs planted specifically to reduce wind speed over a large area, usually adjacent to crops or livestock housing.
Why are Windbreaks Important?
Windbreaks perform several vital functions on the farm:
- Reduce Soil Erosion: They slow down high winds, which prevents the surface layer of soil (topsoil) from being blown away (wind erosion).
- Protect Crops: High winds can physically damage plants, cause lodging (plants falling over), and reduce yields.
- Reduce Evaporation: By slowing the wind, they lower the rate of transpiration (water loss from plants) and evaporation from the soil surface, meaning crops need less irrigation.
- Protect Livestock: They provide shelter from harsh winds, reducing the stress and energy livestock spend trying to stay warm or cool.
Did you know? The most effective windbreaks are permeable (allow some air through) rather than completely solid. A solid wall creates turbulence and eddies on the leeward side, which can still damage crops. A porous windbreak slows the wind smoothly.
Key Takeaway: Fencing, hedging, and windbreaks are all critical structural tools used for boundary control, security, erosion prevention, and creating a healthier microclimate on the farm.