Zeolite in Agriculture — what it can really do and why it works
Nitrogen in agriculture has a utilization efficiency of only 30 to 40 percent. The rest escapes into the air or groundwater — as lost money and environmental pollution. Zeolite can fundamentally change this. Not as a miracle cure, but as a system improver that has been scientifically studied for decades and works in practice.
What is healthy, productive soil? This question sounds simple — and its answer is something agriculture is just relearning. It's not just about adding nutrients to the soil. It's about soil that can retain nutrients, store water when it rains and release it when it's dry, provide a living environment for microorganisms, and do all of this long-term and sustainably.
This is precisely where clinoptilolite zeolite comes into play.
What is zeolite — and what makes it so special?
Zeolite is a volcanic mineral that formed millions of years ago when lava met the sea. This created tiny cavities and channels in the rock — a microporous structure that makes zeolite an extraordinary mineral.
The crucial property: Clinoptilolite zeolite has a cation exchange capacity (i.e., the ability to bind positively charged nutrients and release them again) of 150 to 250 cmol/kg — which is exceptionally high. In comparison: simple rock flour made from basalt or granite has hardly any measurable exchange capacity. This is the fundamental difference between zeolite and simple rock flour — a question that farmers repeatedly ask us.
This structure makes zeolite a natural slow-release fertilizer, water retainer, and soil improver all in one — durable, without degrading, without chemical additives.
As Sangeetha & Baskar (Agricultural Reviews, 2016) put it: Zeolite can be used both as a carrier of nutrients and as a medium for the controlled release of nutrients — its main application in agriculture is nitrogen binding, storage, and slow release.
The basic problem — and why zeolite is the solution
Nitrogen: Only 30–40% of applied nitrogen reaches the plant. The rest is leached out (= enters groundwater as nitrate) or escapes into the air as ammonia. This costs money and harms the environment.
Zeolite binds ammonium nitrogen (NH₄⁺) in its crystal lattice. It releases it gradually — precisely when the plant root can absorb it. The result: more nitrogen for the plant, less loss, less fertilizer needed.
Studies show: A combination of clinoptilolite and only 75% of the recommended fertilizer amount yielded the same harvest as 100% fertilizer alone. 25% fertilizer savings with the same result — that is measurable and verifiable.
Water: Zeolite can store more than half its weight in water — and releases it in a controlled manner. In sandy soils, zeolite increases plant-available water by at least 50%. In dry periods, this means: the plant suffers less, the yield remains more stable.
Phosphorus and Potassium: Zeolite also improves the availability of phosphorus and potassium in the soil. Ammonium-loaded zeolites can promote the dissolution of phosphate rocks, thereby improving the phosphorus supply to the plant — without additional fertilizer.
Soil: Zeolite improves soil structure, promotes aeration, and creates a habitat for microorganisms. It remains permanently in the soil — it does not weather and is hardly leached out. A single incorporation works for many years.
What research shows — an overview
Research into zeolite in agriculture began in Japan in the 1960s. Since then, hundreds of studies have been published worldwide. Here is an overview of the most important results:
Field Crops — Wheat and Beets, France
Field trials by the Oekomineral Group with GRÜNKRAFT (then Plantos Verde) showed an increase in wheat yield of 5 to 13 quintals per hectare with a single foliar treatment. For beets, yield increased by 7%, sugar content by 8%.
Corn — Greece 2024
Three field trials in Greece (Athens, Messolonghi, Karditsa) showed: With zeolite in the soil, corn yield increased significantly — with improved nitrogen and water use efficiency. Less fertilizer for more yield.
Source: MDPI Sustainability, DOI: 10.3390/su17052178, 2025
Corn on acidic soils — PLOS ONE 2018
25% less fertilizer use with the same corn yield — thanks to clinoptilolite in the soil. Additionally: measurably more microorganism growth, better nutrient uptake, and humus formation.
Source: PLOS ONE, DOI: 10.1371/journal.pone.0204401
NPK — all three main nutrients simultaneously
Clinoptilolite improved the availability of nitrogen, phosphorus, and potassium simultaneously — and strengthened the soil's buffering capacity against pH fluctuations. Less nutrient loss into groundwater, more for the plant.
Source: MDPI Agronomy, DOI: 10.3390/agronomy11020379, 2021
Viticulture — Saint Emilion, Merlot
GRÜNKRAFT treatment on Merlot vines in Saint Emilion showed: Grape weight +15% (173 vs. 150 g per 100 grapes), higher total polyphenol index, more assimilable nitrogen for winemaking, better acidity for freshness and color stability.
Viticulture — Protection against Downy Mildew
An independent test by VEGEPOLYS Innovation (France, 2016) showed: GRÜNKRAFT treatment reduced downy mildew (Plasmopara viticola) infestation by 24% compared to the untreated control. Researchers spontaneously noted: treated vines had thicker, darker green leaves and more vitality than all other groups.
ECO-ZEO Project — EU Research 2012–2016
The European research program FP7 confirmed in extensive laboratory and field studies: Zeolite measurably improves water retention, nutrient availability, and plant growth — across all crops and climate zones studied.
Zeolite on the leaf — what GRÜNKRAFT achieves
Zeolite works not only in the soil — but also directly on the leaf. This is the core idea behind GRÜNKRAFT CALCIUM and GRÜNKRAFT Zeolith pur.
Dr. Peter Ost, zeolite pioneer, explains the mechanism:
"Lime and zeolite on the leaf surface stimulate microorganisms. These can absorb ammonia from the atmosphere and make it available to the leaf. This is also why the leaves turn dark green. They are supplied with nitrogen from the atmosphere, a natural nitrogen." — Dr. Peter Ost, zeolite pioneer
This means: Foliar-fertilized crops get nitrogen directly from the air — naturally, without chemicals. At the same time, the silicate particles on the leaf surface form a mechanical barrier against pests like mites and aphids.
GRÜNKRAFT products, thanks to the tribomechanical grinding process (= gentle crushing where particles collide with each other, no metal abrasion), have a particle size of less than 8 micrometers — making them stomata-permeable (= they fit through the tiny pores of the leaf surface). This is the crucial difference to conventional foliar fertilizers.
All GRÜNKRAFT products are organic-compliant according to VO (EU) No. 2018/848 and listed with InfoXgen/Easy-Cert.
For which crops — a brief overview
Cereal cultivation: Wheat, barley, corn — zeolite as a soil additive and foliar fertilizer increases yield and protein content. Studies from France, Greece, and Malaysia prove it.
Beets and potatoes: Yield, sugar content, and size homogeneity increase. Potatoes can also be stored longer with zeolite — a tip that comes from ancient knowledge.
Viticulture: Sun protection, pest repulsion, quality improvement — zeolite as a foliar fertilizer is particularly versatile in viticulture. More on this in the dedicated viticulture article.
Vegetable cultivation: Lettuce, cucumber, kohlrabi, melon, leek, celery — in trials, all crops showed positive reactions to GRÜNKRAFT treatments: higher yields, better quality, longer shelf life.
Herb cultivation: Herb growers report a third cut for lemon balm with regular GRÜNKRAFT and lime treatment — normally only two cuts per year are possible.
Grassland: Where the slurry goes, you see the difference. Where it doesn't go, you see it too. Zeolite in slurry improves nutrient availability on the meadow — visibly, measurably.
Zeolite vs. rock flour — important question
"Isn't zeolite just rock flour?" — farmers ask us this question repeatedly. The honest answer: No. The difference is fundamental.
Simple rock flour from basalt, granite, or diabase has low to no cation exchange capacity, hardly any ion exchange ability, and no selective binding of ammonium. It is a soil amendment — no more and no less.
Clinoptilolite zeolite has a cation exchange capacity of 150–250 cmol/kg, an active surface area of over 600 m² per gram, a selective binding capacity for ammonium and potassium, and biochemical processes are greatly accelerated on its surface.
1 gram of STEINKRAFT zeolite = over 600 m² of active surface area. This is the difference between an ordinary rock and a volcanic mineral that took millions of years to develop this structure.
What farmers report from practice
"Since I started using GRÜNKRAFT Calcium and GRÜNKRAFT Zeolith pur for my fields, I've noticed a significant improvement in plant health and yields." ⭐⭐⭐⭐⭐
"Through this measure, we really got large, strong grains of good, dry quality. In 1 year, we will put a superb raw product into barrels and enjoy it from the bottle in 4 to 10 years." — Destillerie Farthofer, Öhling
"For potatoes, we used GRÜNKRAFT CALCIUM and AM+PLUS and had no potato beetles. The plants stayed green 2–3 weeks longer than all the surrounding farms. We also had zero wireworms. From 2,000 m², we harvested 5 tons of potatoes." — Bernhard & Helene Keplinger, Bad Leonfelden
Our products for agriculture
👉 BODENKRAFT PUR — 100% activated natural clinoptilolite zeolite for the soil 👉 GRÜNKRAFT CALCIUM — Calcium foliar fertilizer with zeolite, stomata-permeable, organic-compliant 👉 GRÜNKRAFT Zeolith pur — pure zeolite foliar fertilizer for arable and viticulture crops 👉 AM+PLUS Active Microorganisms — for soil, slurry, and foliar spraying 👉 BODENKRAFT K / MK — Lime for pH regulation and basic supply
Read more — specific articles
From research to practice — why zeolite could be the future of agriculture
Why zeolite works in the soil — the scientific basis
5 applications of zeolite and AM+PLUS in agriculture — experience report
Sources
Sangeetha C. & Baskar P. (2016): Zeolite and its potential uses in agriculture: A critical review. Agricultural Reviews 37(2), pp. 101–108. DOI: 10.18805/ar.v0iof.9627 · MDPI Sustainability (2025): Effects of Zeolite Application on Maize in Greece. DOI: 10.3390/su17052178 · MDPI Agronomy (2021): Nitrogen, Phosphorus, and Potassium Adsorption Using Clinoptilolite Zeolite. DOI: 10.3390/agronomy11020379 · PLOS ONE (2018): Effects of clinoptilolite zeolite on yield of Zea Mays L. DOI: 10.1371/journal.pone.0204401 · Oekomineral Group / Tribo Technologies (2011–2014): Technical studies and field trials Plantos Verde · VEGEPOLYS Innovation (2016): Report DV1605-1260 — Evaluation of protection efficiency against downy mildew on grapevines · ECO-ZEO Project (2012–2016): EU FP7 Research Initiative · Mumpton F.A. (1999): La roca magica. PNAS 96(7), pp. 3463–3470 · Dr. Peter Ost, Zeolite Pioneer: Quote from STEINKRAFT Agriculture Blog
