Is water retention capacity related to water availability?
No. The water retention capacity of polymers is not necessarily relevant in terms of performance, because high water retention capacity does not mean high water availability. While most hydrogels (primarily produced for the diaper and sanitary wares industry) can absorb hundreds of times their own weight in water, they are designed to irreversibly bind the moisture, and may compete with the plant roots for the same water. Thus, no water is made available to the plant. Additionally, no water retention capacity is absolute. The higher the level of minerals or impurities in the water, the lower the water retention capacity is. Even given the same water quality, when mixed into the ground the water retention capacity will decrease with higher soil pressure.
