Microbes living in and on the roots of plants keep them healthy just as the human gut microbes do. During drought conditions, plants increase the microbes which help them stay alive in drought conditions. Researchers have found they can inject more microbes when droughts are extreme, to relieve the stress of the plant.
In home gardens, the UK Royal Horticultural Society lists the variety of plants which have additional features they have evolved to make them drought resistant:
Top five drought-resistant plants:
- Abelia × grandiflora AGM
- Buxus sempervirens AGM
- Euphorbia characias subsp. wulfenii AGM
- Sedum spectabile AGM
With some conditioning of the soil and careful watering, there is a considerable range of plants that can tolerate dry conditions once they are established.
- Plant any silver leaved, less hardy, sun lovers in April so they establish their roots well before winter arrives
- Try to plant small specimens so that they get used to their growing environment gradually as they develop
- Adding organic matter to the soil before planting can help to improve both water availability and drainage, but do not add fertiliser, as this can encourage too much lush growth which may flop in summer, require extra watering, and be affected by frost in the winter
- Use mulches to retain moisture in the soil
Many drought tolerant plants have silver or grey-green leaves, their light leaf colour reflecting the harsh rays of the sun. Some have a coating of fine hairs on their leaves or stems, helping to trap moisture around the plant tissues.”
Food insecurity is now a big issue for the world with endless threats from serious weather events, conflicts, breakdown of ecosystems due to mismanagement of farmland and so on.
The ongoing heatwaves have reduced major rivers to narrow, silt filled streams such as the Colorado and Mississippi rivers in the US, river Po in Italy, Rhine in Germany to name but a few.
As farmers lose their businesses, solutions are needed and we look to genetic alterations and new farming techniques to transform the ability to keep the food supply going.
Drought resistant crops are being selected by farmers who have found themselves no longer able to plant their usual crops due to climate change impacts.
The above article by a Welsh university department explains the new challenges for the future of farming in drought conditions, such as rainwater harvesting, succession planting or switching to winter crops.
The authors underline that globally we are experiencing greater “frequency and severity of drought, heatwaves and flooding are predicted to increase and pose a direct threat to food security across the globe.”
These researchers study the variety of genetic mechanisms which help or hinder crops when faced with unexpectedly arid conditions:
.. ………..”that in barley the movement of gas through the stomata and levels of chemicals (sodium and potassium) inside cells are more important than root length and the density of stomata in the leaves. Interestingly, this evidence indicates that barley relies more on osmotic adjustment at a cellular level than larger changes in morphology like root length. Such adaptations fall into the category of drought tolerance and may guide future breeding strategies.”
Other research is developing mechanisms for growing hops when climate change has damaged recent output. Here the researchers have created seed banks.
Hopsteiner, a global hops breeder supports the doctoral work of scientists cataloguing hop plants which grow in habitats threatened by climate change. They collect samples and grow them in a greenhouse and seeds are stored in a Repository to aid breeders and researchers.
Similarly, in an attempt to study plants which may be under threat, Seed Banks are being created. For example, Repositories in Mozambique are funded by the Austrian Development Cooperation and Farmer Field Schools.
Understanding a crop can lead to breeding an adaptable cultivar which will suit the changing climate. There are ideas for olives – see AdaptaOlive:
As we saw from the devastating and ongoing crises in Pakistan recently, the floods obliterated the livelihoods of farmers along the Indus Valley, a major river. Whether it be drought or flood, the result is zero crop and animal farming.