Which plants benefit immensely from clay soil

That is why a drought is fatal for the soil

If the soil is too dry, this can have serious consequences for plants. If the roots of a plant notice that there is a lack of water, they send a kind of alarm signal: A stress hormone is released that ensures that stomata, i.e. the small pores in the leaves, are closed.

Stomata are important for photosynthesis, in which the plant converts carbon dioxide and water into oxygen and glucose. Through them, carbon dioxide gets into the leaf, oxygen and water get out again.

 

A plant can hold around 90 percent waterprevent loss

However, if a plant suffers from drought stress, it tries to keep the water down and therefore closes the stomata. This enables it to prevent around 90 percent of water loss. How much exactly varies from plant to plant.

If the stomata are closed, however, photosynthesis does not take place either. That is, the plant does not grow. It may be that fewer or no flowers are formed. Or there is less or nothing to harvest because grain, fruit or vegetables cannot ripen properly. The taste of fruits and vegetables can also deteriorate.

In Germany, for example, the drought stress of plants in the summer of 2018 was clearly visible on the fruit and vegetable shelves: tomatoes, apples and carrots remained significantly smaller than in summers when there was enough water.

 

In extreme cases, a plant can die

This is bad for farmers and consumers, but the situation is not existential for the plant itself. It only becomes that when closing the stomata is insufficient. If there is still a lack of water, the tissue in the plant collapses because there is no internal pressure. Like a bouncy castle that doesn't have enough air. The plant will wilt and there is a risk that it will die.

Too little water not only makes plants thirsty, they also go hungry. An international research team evaluated studies in which 26 different tree species had been exposed to drought stress in experiments. The result: even though carbohydrates and other nutrients were present, the trees starved to death. Without water, the nutrients could no longer be transported into the trees.