It's one of the most common questions farmers and home gardeners ask us. I have poor soil - should I improve the soil first or start with foliar fertilizer immediately? Do I need both? Which is more effective?
The answer is not either-or. Soil and leaves solve two completely different problems - on two different time scales. Understanding this allows you to make better decisions immediately.
The fundamental difference
Imagine a plant like a person who is sick and at the same time poorly nourished.
The soil is the nutrition - the foundation. If the soil is healthy, the plant has everything it needs long-term: water, minerals, trace elements, a living microbial network that makes nutrients available. Healthy soil nourishes the plant independently, season after season, with little extra effort.
Foliar fertilization is like an infusion directly into the blood - it works immediately, regardless of what is happening in the soil. The plant receives CO₂ and calcium directly into the leaf tissue, photosynthesis runs at full speed, and the Brix value increases within days.
Both are important. But they work on completely different time scales - and that's precisely what determines when you need which method.
What soil fertilization can do - and what it cannot
Soil fertilization - with zeolite, basalt, and microorganisms - builds the foundation. It works slowly, but sustainably and compoundingly. What does that mean?
Zeolite in the soil improves water retention - it stores moisture during dry periods and releases it evenly. It increases the cation exchange capacity - i.e., the soil's ability to bind nutrients and keep them available instead of washing them out with rain. It buffers the pH value in the optimal range.
Basalt provides a broad spectrum of trace elements - silicon, iron, manganese, copper, zinc, cobalt, molybdenum - which are released over months and years through natural weathering. Its paramagnetic properties activate the soil microbiome and triple microbial activity in the root zone.
AM+PLUS microorganisms build true soil life - they make bound minerals plant-available, promote fermentative rather than putrefactive processes, and form the invisible network that a healthy plant root needs.
All of this takes time. Zeolite works from the first season. Basalt unfolds its full potential over several years. A truly living soil with a rich microbial environment - that is the result of several seasons of consistent care.
The limit of soil fertilization: It can no longer save an ongoing harvest. What happens in the soil takes weeks and months to reach the plant. If the plant is in the flowering phase today and needs calcium, no soil fertilizer can close this gap in the next 48 hours.
Soil pH value
An important building block that is often forgotten: the pH value of the soil. Many Austrian soils - especially after years of intensive cultivation - are acidic. Soil that is too acidic blocks the absorption of calcium, phosphorus, and many trace elements - even if they are present in the soil. The plant starves on a full plate.
This is where BODENKRAFT Carbonate Lime comes into play - a tribomechanically activated calcium carbonate lime from Upper Austrian mining with a grain size of 35 micrometers and a soil reactivity (effectiveness in the soil) of over 90 percent. For comparison: conventional lime only achieves around 50 percent soil reactivity and therefore has to be applied in four to six times higher quantities. BODENKRAFT Carbonate Lime, applied once a year at 400 kg per hectare on grassland and 600 kg per hectare on arable land, works significantly more efficiently and at the same time conserves resources.
The special feature: Due to tribomechanical activation (a process in which mineral particles collide at high speed and are electrostatically charged in the process), the surface of the particles is significantly larger and more reactive than with conventional lime. The effect occurs faster - and lasts longer.
A stable pH value in the optimal range is the basic prerequisite for all other soil improvement measures - zeolite, basalt, microorganisms - to unfold their full potential. Anyone who does not adjust the pH will never fully exploit the potential of their soil.
What foliar fertilization can do - and what it cannot
Foliar fertilization - with Grünkraft Calcium and Grünkraft Zeolith Pur - is the direct way. No detours via soil, root, and long transport through the plant stem. The nutrients go directly into the leaf.
The mechanism of action is almost immediate compared to soil fertilization. After penetrating through the stomata, calcium carbonate decomposes into CO₂ and calcium oxide. The CO₂ immediately goes into photosynthesis. The Brix value of the plant increases measurably within 2 to 3 days. The cell walls become more stable. Resistance to fungi and pests increases.
Foliar fertilization works independently of soil conditions. This is its decisive advantage - and at the same time the basis for the bypass effect.
The limit of foliar fertilization: It does not replace what the soil has to provide in the long term. Nitrogen, phosphorus, potassium, and water - the big basic supply issues - come from the soil. Foliar fertilization activates and optimizes what is available. But if the soil is fundamentally depleted, it can only compensate for this to a limited and temporary extent.
The bypass effect - when the soil is worse than it should be
Here lies one of the most practically important aspects of foliar fertilization - especially for farms in regions with degraded or leached soils.
If the soil cannot yet, the leaf steps in. And while the leaf secures the harvest, the soil builds up.
What does that mean in concrete terms?
A farmer with weak, mineral-depleted soil has two options. He waits until the soil is productive again through intensive soil improvement - and harvests poor results in the meantime. Or he immediately starts with foliar fertilization, secures the current harvest and at the same time gradually improves the soil.
The second option is the economically and agronomically more sensible one - and it is exactly what Grünkraft Calcium makes possible.
Foliar fertilization provides the plant directly with what it needs: CO₂ for photosynthesis, calcium for cell walls, silicon for defense. The weak soil initially plays hardly any role - the plant is supplied via the leaf.
At the same time, something decisive happens: A plant that intensely photosynthesizes - because it is optimally supplied via the leaf - secretes more root exudates. These are sugars and organic acids that it releases through the roots into the soil to nourish the soil microbiome. Soil life grows. The soil improves - through the activity of the plant itself. So foliar fertilization not only helps the plant. It also indirectly helps the soil.
When soil fertilization - when foliar fertilization - when both
Soil fertilization is the first choice when:
Before planting or sowing - this is the ideal time to incorporate zeolite and basalt. Before the plant is in the ground, you can calmly lay the foundation.
For long-term soil improvement - anyone who wants to regeneratively build up their soil over several seasons cannot avoid zeolite, basalt and microorganisms.
For water problems - too dry soils, too wet soils, waterlogging, uneven moisture - all of this is solved by zeolite as a natural water buffer.
In the event of permanently poor trace element supply - basalt builds up the broad spectrum of minerals that conventional NPK fertilization never provides.
Foliar fertilization is the first choice when:
The plant needs immediate help - flowering, fruit set, ripening. These are the phases where the plant needs more nutrients than the root can deliver from the soil. Foliar fertilization closes this gap directly.
In case of drought stress - if the soil is dried out, nutrient availability in the soil collapses dramatically. Nutrients in the soil are only plant-available in dissolved form - no absorption without water. Foliar fertilization is completely independent of this and still supplies the plant.
If the soil is worse than it should be - the bypass effect. Immediate results while the soil is built up in parallel.
When rapid quality improvement is required - higher Brix value, more secondary plant compounds, better storability. This can be achieved with foliar fertilization in weeks, not years.
Shortly before harvest - a final treatment 2 to 3 weeks before harvest measurably increases the Brix value of the last fruits again. This is the moment many miss.
Both together are the right choice when:
The farmer or gardener wants maximum results - in the short and long term simultaneously.
Soil and leaves not only complement each other - they reinforce each other. A living soil with active microorganisms makes foliar fertilization more effective because more minerals are available for transport in the plant. And a foliar-fertilized plant with high photosynthetic activity improves the soil microbiome through its root exudates - which in turn benefits the soil.
This is not a cycle that should be interrupted somewhere. It is a system that grows stronger with each season.
The three time levels of the complete system
The complete Steinkraft system works on three time levels simultaneously - and that is precisely the difference to individual product solutions:
Long-term - Steinkraft Basalt. Releases trace elements over months and years. Permanently improves soil structure. The paramagnetic properties activate the soil microbiome sustainably. A single autumn application is still effective in the season after next.
Medium-term - Steinkraft Zeolith BODENKRAFT PUR. Improves water storage and nutrient retention from the first season. Buffers the pH value. Releases calcium and potassium to the root as needed.
Immediate - Grünkraft Calcium as foliar fertilizer. Works in days. Independent of soil conditions. Secures the ongoing harvest and immediately increases Brix value and quality.
Anyone who serves all three levels simultaneously harvests more - already in the first season through foliar fertilization and in the following years increasingly through the improved soil.
The practical decision aid
Poor soil, first season, immediate results needed: Start immediately with Grünkraft Calcium as foliar fertilization. At the same time, incorporate zeolite and basalt into the soil. The soil builds up - the harvest will still be good.
Good soil, optimal conditions: Soil fertilization as a foundation, foliar fertilization in the critical phases of flowering, fruit set, ripening and during drought stress.
Already built up good soil: Foliar fertilization as seasonal activation. Photosynthesis runs at full speed. Brix value increases. Quality increases. The foundation is there - now it's being optimized.
Degraded soil, no time for long build-up: The bypass. Grünkraft Calcium immediately. Results come - and the soil is built up in parallel. What the leaf achieves today, the soil takes over tomorrow.
What this means for our soils in Lower Austria
Lower Austrian arable soils - from the Marchfeld to the Waldviertel - have lost humus content and soil life in recent decades due to intensive conventional agriculture. This is not a local problem but a global one. According to a UN report, we lost one third of all fertile soils worldwide between 1950 and 1990.
This means: Many soils today can no longer do what they once could. The plants on these soils are chronically undersupplied - even if the farmer fertilizes with NPK. Because NPK does not replace the 77 other elements that are removed from the soil annually.
This is precisely where the strength of the combined approach lies: foliar fertilization secures the harvest today. Soil building with zeolite, basalt and microorganisms secures the harvest in ten years.
This is not philosophy. These are numbers - from field studies that show that treated soils get better with each year. And Brix values that show that the plants on these soils are healthier and more nutritious than on untreated comparison areas.
The short summary
Soil works slowly, but sustainably - and gets stronger with each season. Like an account that earns interest on itself.
Leaf is the immediate measure - fast, independent, direct.
Both together are the system - the strongest that regenerative agriculture has to offer.
And if the soil cannot yet: The leaf steps in. Today.
What exactly happens in the leaf when Grünkraft Calcium is applied - the complete physiological mechanism - can be found in our article on photosynthesis and foliar fertilization.
All field studies on Grünkraft Calcium from Europe, Colombia and Africa - in the comprehensive study overview.
Why soils worldwide are becoming depleted and what this means for our health - in the article on minerals and damaged soils.
All products for soil and leaf in our Agriculture Collection and Gardening Collection.
