Growth Factors I Water

Water is the most important and limiting growth factor of all. Its molecule is constituted by two atoms of Hydrogen and one of Oxygen united by a covalent bond.

These molecules have polar character, joining together through hydrogen bonds.

The interaction of these dipoles is responsible for the surface tension of the water, related to the ease with which the soil “gets wet”.

This is where surfactants come into play, widely used in the world of greenkeeping. With them, the surface tension of the water decreases, reducing the formation of dew on the surface of the greens and in turn the proliferation of fungal diseases, such as the “dollar spot” on greens coated with dew and low in nitrogen.

Another very important effect of the use of surfactants is the elimination of hydrophobic zones, the “dry patches”. These are attributed to the decomposition effects of basidiomycete fungi. Fungi of the same group as the microorganisms that cause the typical “fairy ring” in the soil.

Hydrophobia is caused by the decomposition of mycelial remains of fungi and organic matter, Dernoeden. P.H, Creeping Bentgrass Management, 2002.

The amount of water that can be taken by the roots, is that surrounding them and therefore will depend on different soil characteristics such as:

• Texture. The capacity of water retention follows this increasing order, depending on the type of soil: Sandy <Frost-Sandy <Limousine <Frosty-loamy <Clay.
• Root length The greater the root length, the greater the water reserve.
• Species and varieties, following the following increasing order of drought tolerance: Bahiagrass> Blue grass> Zoysiagrass and hybrid Bermuda, St Augustinegrass> Seashore paspalum> Fescue> Poa Pratensis> Rye grass> Agrostis> Poa annua.