Education Always

Level: JHS, Basic 7  |  Subject: Integrated Science  |  Strand: Cycles  |  Topic: Crop Production

Curriculum reference: B7.2.3.1 (NaCCA Integrated Science). All the indicators of this sub-strand are merged into one set of notes.

1. What is Crop Production?

• Crop production is the growing of plants for food, for animal feed and for raw materials such as cotton and rubber.
• Examples of crops grown in Ghana: maize, cassava, yam, cocoa, tomato, pepper, okro and plantain.
• Plants need sunlight, water, air and nutrients (food materials) from the soil to grow well.

2. Plant Nutrients

Nutrients are the substances plants take from the soil and use to grow, to stay healthy and to produce fruits and seeds.

Nutrient	What it does for the plant	Sign when it is missing
Nitrogen (N)	Helps leaves and stems to grow green and strong	Yellow leaves, slow growth
Phosphorus (P)	Helps roots to grow and helps flowers and seeds to form	Poor roots, purple leaves
Potassium (K)	Helps the plant to resist diseases and to make good fruits	Brown edges on leaves
Calcium, magnesium, iron and others	Needed in smaller amounts for healthy growth	Weak plants, patches on leaves

Remember: N, P and K are the three main nutrients. You will see them on a bag of fertilizer as NPK.

3. Ways of Supplying Nutrients to Crops

Soil can lose its nutrients when crops are grown on it year after year. Farmers return nutrients to the soil by using manure or fertilizer.

(a) Organic manure

• Made from plant and animal materials that have rotted, for example compost, poultry droppings, cow dung and green manure.
• Advantages: cheap, improves the soil structure, holds water, releases nutrients slowly, safe for the environment.
• Disadvantages: bulky and heavy to carry, slow to act, contains smaller amounts of nutrients.

(b) Inorganic fertilizer

• Made in factories from chemicals, for example NPK, sulphate of ammonia and urea.
• Advantages: rich in nutrients, works fast, easy to carry and apply.
• Disadvantages: costs more, can burn the plants if too much is used, can pollute water, does not improve the soil structure.

Point	Organic manure	Inorganic fertilizer
Source	Plants and animals	Factory chemicals
Speed	Slow	Fast
Cost	Cheap	Expensive
Effect on soil structure	Improves it	Does not improve it
Example	Compost, cow dung	NPK, urea

4. How to Make Compost

1. Choose a shady place and dig a pit or make a heap.
2. Put in layers of dry plant waste (dry leaves, grass, maize stalks) and green waste (kitchen peelings, fresh weeds).
3. Add a layer of animal droppings and a little soil.
4. Sprinkle water to keep it moist and turn it every one to two weeks.
5. After about two to three months it becomes dark brown and crumbly. It is now ready to use.

5. Applying Manure and Fertilizer

• Broadcasting: spreading it evenly over the whole field.
• Side placement or ring method: placing it in a ring or a line a little away from the stem.
• Dissolving in water: used for vegetables in small gardens.
• Never let fertilizer touch the stem or leaves, because it can burn them. Wash your hands after using it.

6. School Farming

A school farm helps learners to practise farming and to grow food for the school. These are the usual steps.

1. Choose a site: flat land with good soil, near water and away from flooding.
2. Clear and prepare the land: remove weeds and stumps, then dig or make beds and ridges.
3. Select good seeds: healthy, clean and not damaged.
4. Plant at the right spacing and at the right depth, at the start of the rains.
5. Weed, water and apply manure when needed.
6. Control pests and diseases (for example by handpicking insects or using safe pesticides under a teacher).
7. Harvest on time, then store or sell the produce.
8. Keep records of dates, work done, costs and income.

Safe farm practices: wear boots and gloves, handle cutlasses and hoes carefully, keep chemicals away from children and wash your hands after farm work.

Remember: Plants need nutrients to grow well. Organic manure feeds the soil slowly and improves it, while inorganic fertilizer feeds the plant quickly but costs more and must be used carefully.

Education Always (education.inspiringalways.com). Original notes written to follow the NaCCA Basic 7 Integrated Science curriculum.