Nutritional density in our food has plummeted by 20% to 80% over the last 80 years. For farmers, this isn’t just a health statistic, it’s a reflection of soil degradation and a direct hit to livestock health, crop resilience, and marketability.
At Agresol, we believe yield shouldn’t come at the cost of quality. By focusing on nutrient density, you can increase crop yields, reduce vet bills in livestock systems, and lower susceptibility to pests and diseases. Here is the framework we use to help our clients bridge the nutritional gap
The Root of the Problem: Why Density is Declining
The decline in nutritional quality is largely driven by two factors: soil degradation and microbial loss.
Soil Health: Approximately 66% of Australia’s soils are degraded due to erosion, acidity, compaction, and a 50% loss in soil organic carbon.
The UK/US Trend: Studies show that nearly every mineral concentration in food has declined since the 1940s, with the exception of phosphorus, which increased due to heavy fertilizer use.
While some attribute this to a “dilution effect” from high-nitrogen fertilizers forcing empty biomass growth, the underlying cause is often a broken connection between the plant and the soil’s mineral component.
6 Levers to Increase Nutrient Density
1. Plant Variety and Populations
Modern breeding often prioritizes yield and carbohydrates over mineral content.
Heirloom Varieties: Older varieties often have more extensive root systems and a better ability to form connections with soil microbes.
Evolutionary Plant Breeding: Consider developing “landrace” populations. By sowing a diverse mix of varieties and retaining the seed year after year, the population adapts specifically to your farm’s soil and climate. This “Wakelands population” approach provides massive genetic diversity and resilience.
2. Maximizing Soil Health
Soil health is driven by biology. Microbes unlock minerals from the “total” component of the soil—minerals that are physically present but chemically locked away.
Mycorrhizal Fungi: These fungi live inside roots and extend the root zone significantly to scavenge water and nutrients.
Rhizophagy Cycle: Plants actually “consume” microbes in their root tips to obtain nutrients, minerals, and growth-promoting compounds.
To stimulate this, follow the five soil health principles: reduce disturbance, increase ground cover, maximize diversity, maintain living roots (photosynthesis), and integrate livestock .
3. Soil Applications
If a soil test reveals an absolute geological deficiency (e.g., a lack of copper or molybdenum), soil applications may be necessary. However, these are often only 2% to 5% efficient because soil antagonisms can quickly lock the minerals back up.
4. Strategic Nitrogen Management
Over-applying nitrogen forces biomass growth but can dilute other nutrients.
Optimization: Use split applications or foliar nitrogen.
Buffering: Always add humates to synthetic nitrogen to reduce losses and protect soil biology.
5. Seed Primers and Treatments
Adding trace minerals directly to the seed is one of the most cost-effective ways to ensure early-stage plant health. One study found a 12% increase in zinc in the harvested grain just by applying a small amount to the seed at planting.
6. Foliar Applications: The “Short Circuit”
Foliar sprays are the most efficient lever we have, with up to 95% uptake. They bypass soil lock-ups and allow the plant to internalize minerals immediately.
Late-Stage Enrichment: Applying minerals like zinc, iron, or manganese during grain fill or fruit fill can double the nutrient content of the final produce.
Broad Spectrum: Unless you have a sap test, use a broad-spectrum trace mineral mix to avoid creating new antagonisms.
The “Regen Year” Strategy
If you have a paddock that is underperforming, we recommend a Regen Year. Rather than a cash crop, grow a diverse multi-species forage crop and graze it off with livestock. This integrates all five soil health principles simultaneously to “reset” the biological system and build available mineral reserves for future crops.
