Trees ‘drink’ from capillary water. Their instrument to drink from the capillary water is the primary root. You can know how deep the earth has capillary water, because at a certain point the earth becomes darker. This is where the primary root connects with the capillary tubes (vertical tubes that carry the water).
When there is heavy rains, excess water runs underground through these capillary tubes. When the surface is dry, these same tubes transport the water to the surface. Trees have their roots in these capillary tubes, which also contain threads of fungi which are hygroscopic (attracting water); And with their lateral roots, they absorb the capillary water when it’s hot and dry. This is how a tree survives heat and drought. Even on rocks, trees produce tiny, invisible fissures to access the capillaries.
Rain in deserts
Even in the less mild climates, there is more than enough supply of capillary water in the soil for a tree to survive and grow. In fact, it rains more in the deserts than we think (often between 150 and 250 millimeters per year, which is equivalent to 150 to 250 liters per m2). The problem is not the lack of precipitation, but the duration in time that the rain falls. In some places, it rains for 1 month, and remains dry for the remaining 11 months. When the wet period is too short to allow the young roots to reach the capillary water, the young tree dies. If the wet period is long enough, and the roots reach the capillary water, the tree can survive. There are rocky places (eg the Alps, the Rocky Mountains), or in savannas (for example, Mali, Mauritania), then we see that in these cases huge trees grow easily.
Nature can form its own ecosystem with capillary water
If we supply the amount of water required during the early stages, when a tree is still young and its roots have not grown enough to reach capillary water, trees can grow almost anywhere. A forest is able to create by itself, the right conditions to stimulate and aid growth of trees. Trees create a different and unique microclimate where they grow, as they provide shade for other plants; They attract animals that distribute seeds; The soil becomes more loose and rich, and receives organic matter that is capable of containing water and nutrients. A slow environment is formed in which various plant and microscopic species can grow (nature has always done this without our help transforming bare rock into rich soil for cultivation).
How to prevent the loss of capillary water by evaporation.
The best technique to keep capillary water in the soil is to add a layer of surface soil because during the day the capillary water evaporates due to the direct heat of the sun in the soil. Fifty years ago in Holland, when there was no irrigation, farmers used an old technique to loosen the top layer, which combined keeping moisture with weed control, the instrument used for this purpose was the “roller scraper”. Loss of soil water and the technique used to prevent it.
The following video explains in a very simple way the capillary water principle:
Source of the News: Groasis