Using Broad Beans in the Lab
ResourceQuick and reliable to germinate in the lab, broad beans are a member of the pea and bean family, the Fabaceae, and so an excellent example for topics including mutualism and nitrogen fixation.
Practicals
- Nitrogen fixation – Observation of root nodules containing nitrogen-fixing bacteria
Teaching Topics
- Nutrient Cycles
- Nitrogen fixation
- Mutualism
Image resources
Description
Broad Bean, Vicia faba
A hardy bean, cultivated since Neolithic times. Broad beans have nodules containing nitrogen-fixing bacteria on its roots – a common feature of the Fabaceae (the Pea and Bean family, previously known as the Leguminosae).
Growing and sourcing
Obtaining: Grow from seed, which are available from garden centres, nurseries and horticultural suppliers such as Thompson and Morgan.
Care: For school use, broad beans can be sown indoors, either in seed compost or in damp filter paper, in jars.
Soak your beans for one hour then wrap damp filter paper round the inside of the jars and place the bean seed between the damp paper and the jar. Keep the bean moist and well-lit. The bean should sprout in 4 days. Students can observe and record if and/or when root nodules are visible.
When sown outdoors some broad bean varieties, such as Super Aquadulce, can be planted in Autumn, survive the winter cold and be ready for early summer harvest.
