Database results:
examBoard: Cambridge
examType: IGCSE
lessonTitle: Drought-resistant Crop Varieties
As our climate changes and water becomes scarcer in many regions, growing crops that can thrive with less water is becoming essential for food security. Drought-resistant crop varieties are specially bred or selected plants that can produce reasonable yields even when water is limited.
Key Definitions:
Climate change is causing more frequent and severe droughts in many agricultural regions. At the same time, growing populations need more food and agriculture already uses about 70% of the world's freshwater. Drought-resistant crops help farmers produce food with less water, making agriculture more sustainable and resilient.
Drought-resistant crops reduce water consumption in agriculture, helping preserve this precious resource. They also reduce the need for irrigation, which can lower energy use and prevent problems like soil salinisation. These crops can help maintain food production in areas affected by climate change without expanding farmland into natural habitats.
Plants have evolved various mechanisms to cope with water scarcity. Understanding these mechanisms helps scientists develop better drought-resistant varieties.
Deeper, more extensive root systems allow plants to access water from greater depths in the soil. Some drought-resistant varieties can grow roots up to 2 metres deep, compared to 30-60 cm in conventional varieties.
Smaller leaves, waxy coatings and tiny hairs reduce water loss through transpiration. Some plants can roll their leaves or have fewer stomata (pores) to minimise water loss during dry periods.
Drought-resistant plants often produce special proteins and sugars that protect cells from dehydration damage. They may also adjust their metabolism to use water more efficiently during photosynthesis.
Scientists have developed drought-resistant varieties for many important food crops. These include both traditionally bred varieties and those developed using modern techniques.
The Water Efficient Maize for Africa (WEMA) project has developed drought-tolerant maize varieties for farmers in Kenya, Uganda, Tanzania, South Africa and Mozambique. These varieties, marketed as "DroughtTEGO," can produce up to 30% more yield during moderate drought compared to conventional varieties. By 2020, over 5 million smallholder farmers had adopted these varieties, significantly improving food security in drought-prone regions. The project demonstrates how drought-resistant crops can make a real difference in vulnerable communities.
Drought-resistant crop varieties contribute to sustainable agriculture in several important ways:
Drought-resistant crop varieties aren't a new concept. Farmers have been selecting plants that perform well in dry conditions for thousands of years. However, modern science has accelerated this process.
Traditional breeding involves crossing plants with desirable traits and selecting the best offspring over many generations. This approach has created naturally drought-resistant varieties like sorghum and millet. It's slow but has produced crops well-adapted to local conditions.
Modern approaches include marker-assisted selection (using genetic markers to identify plants with drought-resistant traits) and genetic modification. These methods can develop new varieties more quickly. For example, scientists have identified genes that help plants survive drought and can now breed varieties that express these genes more strongly.
In eastern India, where rice farming depends heavily on monsoon rains, drought can devastate harvests. The International Rice Research Institute developed "Sahbhagi Dhan," a drought-tolerant rice variety that can yield 0.8-1.0 tonnes per hectare more than traditional varieties during drought. Since its introduction in 2010, over 3 million farmers have adopted this variety. In drought years, farmers growing Sahbhagi Dhan have harvested crops when their neighbours' fields failed completely, showing how drought-resistant varieties can be a lifeline for vulnerable communities.
While drought-resistant crops offer many benefits, they also face several challenges:
Research into drought-resistant crops continues to advance. Scientists are exploring several promising directions:
New breeding techniques like CRISPR gene editing allow more precise changes to plant genomes. Scientists are also using artificial intelligence to analyse vast datasets and identify promising drought-resistance traits more quickly. These technologies could accelerate the development of improved varieties.
Drought resistance isn't just about plant genetics. Researchers are also exploring how soil microbes can help plants withstand drought and how farming practices like conservation agriculture can complement drought-resistant varieties by improving soil water retention.
Drought-resistant crop varieties are a crucial tool for sustainable agriculture in a changing climate. They help farmers produce food with less water, improving both environmental sustainability and food security. While challenges remain, ongoing research and development are creating ever more effective drought-resistant crops. By combining these improved varieties with good agricultural practices, farmers worldwide can build more resilient food systems that can withstand the challenges of climate change.
Log in to track your progress and mark lessons as complete!
Login NowDon't have an account? Sign up here.