Grade 4 Agriculture Study Notes

Conservation of Resources

We get resources like soil, water, fuel and animals from the environment. Conservation of resources means using and protecting these resources carefully so they are not damaged or used up.

What you will learn in this strand

• Soil Conservation — making compost manure to keep soil healthy.
• Water Conservation — using drip irrigation to avoid wasting water.
• Fuel Conservation — using fuels wisely at home.
• Conserving Wild Animals — protecting wild animals while keeping crops safe.

Soil Conservation

Soil conservation refers to methods used to prevent soil erosion and pollution.

• Soil erosion — when wind or water carries away the top layer of soil.
• Soil pollution — when harmful things are added to the soil.

Both erosion and pollution damage the soil and make it hard for crops to grow. Making and using compost manure is one way to conserve soil.

Compost Manure

Compost manure is manure made from organic waste — materials from plants or animals that can rot and decompose.

It is made using locally available materials that you might otherwise throw away.

The four stages

1. Organic waste — collect plant and animal waste.
2. Compost heap — pile the waste so it can rot.
3. Ready compost — the waste decomposes into dark, crumbly manure.
4. Apply — spread the ready compost on the farm or garden.

Organic Waste

Organic waste is any material that comes from plants or animals and can rot or decompose.

Examples of organic waste

• Food leftovers
• Fruit peels
• Plant waste
• Animal waste

These materials break down naturally over time. This is what makes them suitable for compost manure.

Suitable Materials for Making Compost Manure

Only organic materials that can decompose are suitable for making compost manure.

Non-suitable Materials

Some materials cannot be used to make compost manure because they do not decompose.

These materials stay in the heap unchanged and will not turn into manure.

Key Points — Soil Conservation

• Soil conservation — methods to prevent soil erosion and pollution.
• Compost manure — made from organic waste (plant or animal materials that decompose).
• Organic waste — food leftovers, fruit peels, plant waste, animal waste.
• Suitable — dry leaves, fruit peels, grass cuttings, maize cobs, banana leaves, food leftovers, animal waste, ash, top soil.
• Not suitable — old cans, plastic bottles, broken glass (do not decompose).
• Collect — separate organic waste from other waste at home.
• Heap method — heap built on the ground surface in a wooden frame; no pit.
• Care — turn every two weeks; keep moist; keep covered.
• Ready when — after about three months; compost turns dark in colour.
• Benefits — makes soil fertile; reduces chemical fertilisers; conserves environment; saves money.
• Apply — spread around plant bases or mix into soil; improves crops and conserves soil.

Heap Method Steps at a Glance

Suitable vs Not Suitable

Where to Find Compost Materials

Compost materials are found at home and in the local environment. You do not need to buy them.

How to Separate and Collect Waste

When you throw away waste at home, separate organic waste from the rest. Keep fruit peels and food scraps apart from plastic and glass.

This makes it easy to collect the materials you need for the compost heap.

Gather the separated organic materials and keep them ready to add to the heap.

The Heap Method

The heap method is a way of making compost manure by piling organic materials on the ground surface.

In the heap method, no pit is dug. The materials are built up in layers inside a wooden frame placed on open ground.

Materials Needed to Build the Heap

Before you start building, gather all the materials you need.

• Posts and wooden planks — to build the frame
• Maize stalks or other plant materials — for the bottom layer
• Cut grass or crop remains — for plant waste layers
• Kitchen waste — food scraps and peels
• Ash — sprinkled between layers
• Animal manure — sprinkled between layers
• Water — to keep the heap moist

Steps to Build the Compost Heap

1. Mark where to put the posts. Dig holes. Fix the posts and wooden planks to form a frame.
2. Arrange maize stalks or plant materials at the bottom of the frame.
3. Add layers of plant waste — cut grass or crop remains.
4. Sprinkle a small amount of ash and animal manure over the layers.
5. Add kitchen waste. Add another layer of plant materials. Repeat to the height you want.
6. Sprinkle water to keep the heap moist.
7. Cover the heap with a layer of soil or waterproof material.

Making Compost Manure

Once the heap is built and covered, the making of compost manure has begun. The organic waste inside will slowly decompose and turn into manure.

Heat and moisture trapped inside the covered heap help the materials break down faster.

From the outside, the completed heap looks like a rectangular mound inside a wooden frame with a covered top.

Caring for the Compost Heap

After building the heap, give it regular care so the manure forms well.

Points to note

• Turn the heap once every two weeks. Use a fork or stick to mix the materials. This makes the compost ready faster.
• Keep the heap moist — sprinkle water when it looks dry.
• Keep the heap covered to hold in heat and moisture.

How to Know When Compost is Ready

Watch the heap for these two signs:

• Compost takes about three months to be ready.
• The compost turns dark in colour when it is fully decomposed and ready to use.