Leguminous Crops SS2 Horticulture and Crop Production Lesson Note

Class: SS2

Subject: Horticulture and Crop Production

What are Leguminous Crops?

Legumes are plants that produce seeds in a pod. They are very special because they have tiny “bumps” on their roots called Nodules. Inside these nodules live friendly bacteria that take Nitrogen from the air and give it to the plant.

In Nigeria, the “Big Three” legumes are Cowpea (Beans), Soybean, and Groundnut.

Cowpea (Beans)

Cowpea is the most common legume in our markets. It is the “meat of the poor” because it provides a lot of protein at a cheaper price than beef.

• Land Preparation: Clear the land and make ridges. Cowpeas like well-drained soil; they hate “wet feet” (waterlogged soil).
• Planting: Plant 2 to 3 seeds per hole at a depth of about 3cm.
• Spacing: 75cm between rows and 25cm between plants.
• Special Care: Cowpeas are “insect magnets.” You must be ready to spray them to stop the Maruca pod borer from eating the flowers.
• Harvesting: Pick the pods by hand when they turn yellow or brown and feel brittle (dry).

Soybean

Soybean is the “industrial legume.” It is used to make vegetable oil, baby food (soya milk), and animal feed for chickens and pigs.

• Land Preparation: Same as cowpea, but soybeans need a bit more phosphorus in the soil to grow well.
• Planting: They are usually planted in rows. The seeds are small, so don’t bury them too deep.
• Weeding: Soybeans grow slowly at first. If you don’t weed the farm early, the grass will grow over them and “hide” them from the sun.
• Harvesting: This is tricky! You must harvest as soon as the pods are brown. If you wait too long, the pods will “pop” open (shatter) and scatter the seeds on the ground where you can’t pick them.

Groundnut (Peanut)

Groundnut is a “hidden” crop because the seeds grow under the soil, not on the branches.

• Land Preparation: Groundnuts need Sandy-Loam soil. If the soil is too hard or clayey, the “pegs” (the parts that become nuts) cannot push into the ground.
• Planting: Remove the seeds from the shells carefully so you don’t break the thin red skin. Plant one seed per hole.
• The “Pegging” Stage: After the yellow flowers fall off, the plant sends “pegs” down into the dirt. Do not disturb the soil at this stage!
• Harvesting: Pull the whole plant out of the ground when the leaves turn yellow and the inside of the shells has dark brown markings.

Summary Table for Revision

Why Legumes are “Farm Heroes” (Advantages)

1. Soil Healing: As we mentioned, they add Nitrogen to the soil. If you plant maize on a field where beans grew last year, the maize will grow very green and strong.
2. Human Health: They are the best source of plant protein for building muscles and repairing the body.
3. Cover Cropping: Many legumes (like cowpea) spread on the ground like a carpet, which stops the sun from drying the soil and prevents erosion.

Storage Secrets

The biggest enemy of legumes is the Weevil.

• Always dry the seeds until they are very hard.
• Use airtight containers (like plastic drums with tight lids) or “PICS bags” (triple-layered bags) to keep the insects out.
• Never store wet beans, or they will grow mold and smell bad.

Teacher’s Classroom Demonstration

Carefully pull a young bean or groundnut plant out of the school garden (with the roots intact). Wash the roots in a bucket of water and show the students the tiny white “nodules.” Tell them: “These are the plant’s food factories!”