Strong plants - it's easy!
Growth and development of plants are dependent on the ratio of water and air in the soil
Soil moisture is one of the most important parameter involved in pedological processes and plant growth. There are three basic forms:
- water that adheres in thin films to the surface of soil particles by molecular attraction is termed hygroscopic water. It is not available for plants;
- water forming thicker films and occupying the smaller pore spaces is termed capillary water. Since it is held against the force of gravity it is permanently available for plant growth and it is this type of soil water which contains plant nutrients in solution;
- water in excess of hygroscopic and capillary water is termed gravitational water, which is of a transitory nature because it flows away under the influence of gravity. When the excess has drained away the amount of water retained in the soil is termed its field capacity, when some of its pore spaces are still free of water.
Water and soil conditions
Spaces between the soil
particles totally filled with water.
Soil at field capacity.
Spaces between the soil
particles filled with water
|Soil at wilting point.
Spaces mostly filled with air, with a small amount of water held tightly around the soil particles.
The water supply to of your plants has a fundamental influence in their development. A sufficient moisture level in the root zone assures that the nutrients in the soil are at their best availability and supports a healthy plant nutrition and optimal growth. In reverse, a lack of soil moisture disturbs the nutrient uptake of plants and often causes a nutrient deficit.
Reducing water stress of your crop comes with several profits for you:
- improving plant growth & quality
- increasing your yield
- strengthening plant health and disease resistance
Ways of measuring soil moisture:
- Volumetric Water Content shows you how much water is in the soil. It is usually expressed as a percentage. The measured results represent what percentage of total 'volume' of soil is water.
- Soil Moisture Tension shows you how easy it is to extract water from soil. When a soil is saturated, there is plenty of water in the pore spaces and plenty of water coating the soil particles. All this moisture makes it very easy for plant roots to get water and the soil moisture tension is low.
Suggested tensiometer readings at which to start irrigation
(or Critical Soil Moisture Deficit)