The principle

Stability instead of extremes

Plants suffer less from dry spells when the root zone doesn't swing between very wet and very dry, but water remains available more continuously.

Absorb

With rain or irrigation, the granules absorb water and turn into a gel. Up to 10 g of water per gram of RETENTIS®.

Store

A three-dimensional network forms in the soil that holds water and dissolved nutrients where the roots are active.

Release

As soil moisture drops, RETENTIS® gradually releases the water again. The plant experiences fewer stress peaks.

20 g of granules, 200 ml of water

In time-lapse: 20 g of RETENTIS® absorb 200 ml of water within a very short time. This corresponds to the storage capacity stated in the product data sheet of up to 10 g of water per gram of granules.

Tried and tested

What RETENTIS® does in the soil

Storage capacity, up to

10 l

of water per kilogram of granules, released to the plant over a long period.

Source: Product data sheet (German), p. 2

Common beech without water

+13 days

longer vitality: only on day 30 instead of day 17 had half of the seedlings dried out.

Source: Drought stress trial with beech seedlings

Tomato, Almería 2023

+19 %

yield, with 20% less water than the fully irrigated control.

Source: Tomato trial report

Active period

3–5

years active in the soil, depending on soil type and conditions of use.

Source: Product data sheet (German), p. 2
Common beech seedlings on day 0, both groups equally healthy
The same common beech seedlings after 27 days without water: left with RETENTIS® still green, right dried out
2 % RETENTIS® soil only

Common beech under drought stress

27 days without water.

One-year-old common beech, watered in once, then no more water. One group with 20 g RETENTIS® per liter of substrate, one without.

Drag the slider and see the difference.

Pot trial with one-year-old common beech under identical conditions.

View trial report →

Makroaufnahme von Pflanzenwurzeln mit deutlich sichtbarem, bernsteinfarbenem RETENTIS®-Wasserspeichergel von Agrobiogel, das Wasser und Nährstoffe speichert. Makroaufnahme von RETENTIS® Granulat

RETENTIS® in action

Macro shot from the root zone: the active, amber-colored gel lies directly between the roots. The roots grow through the gel and thus have direct contact with water and nutrients.

At a glance

What makes RETENTIS® special

Water reservoir in the root zone

Extends the time until the next necessary irrigation and protects against drought stress.

Nutrient buffer

Dissolved nutrients can be buffered in the root zone and leaching losses reduced. Fertilizer can be mixed in at the same time.

Active for 3–5 years

Depending on soil type and conditions of use, over several growing seasons.

From a renewable raw material

Made from lignin, a by-product of the timber industry. No synthetic polymers, no microplastics.

Approved & listed for organic use

Nationally approved in Austria under § 9 of the Fertilizer Act (DMG) 2021 (until 2033), marketable EU-wide under Regulation (EU) 2019/515, and in Canada since February 2026. Listed on the FiBL and EasyCert lists for organic farming.

Made in Austria

Produced in a patented process from lignin, a side stream of the pulp industry.

Any questions?

You'll find answers about RETENTIS® in our FAQ. Or write to us at office@agrobiogel.com.

Go to FAQHow RETENTIS® is made