Due to more periods of prolonged drought, soils in a growing number of areas have become hydrophobic (water-repellent). The problem is that using large amounts of water when watering hydrophobic soils, is counterproductive because most of it will wash out. The solution: more frequent watering, using smaller amounts of water. The only way to manage this is through close monitoring.
Soils have pores. The size of these pores can vary, from large pores in sand to very small ones in clay. This is a useful property, because it allows the soil to provide trees and plants with moisture and oxygen.
However, if the soil dries out too far, there is so much air in the pores that they will have to be soaked for a while, until the soil is able to retain moisture again – and have it available for absorption by plants and trees. With dried-out soils, this process of re-moisturizing usually takes place during the winter time, when there is less evaporation and more rain.
By dumping large amounts of water at once, dried-out soil does not have enough time to absorb the water. This is comparable to a dry sponge or chamois that you try to push under water; it just floats back to the surface again. Only if you leave it there for a while, it gradually absorbs the water until all pores are filled.
The effect of a large amount of water at once, is very limited for the mid- and long term
Monitoring helps to better understand the ‘behavior’ of the soil and the effect of waterings. The steeper the peak on the moisture graph, the more water is washing out. By analyzing the sensor data and reviewing the graphs, it is possible to find the right amount of water to maintain the optimal average moisture percentage. Experience shows that this can save up to 70% of the amount of water. In a medium-sized municipality, this can quickly save several hundred thousand liters per growing season.
Smaller, more frequent waterings have a much longer-lasting effect