Why Half of Your Fertilizer Never Feeds Your Crop — and How Biochar Can Help

Did you know that more than half of the fertilizer applied to farms never reaches the crop?

Every year, farmers invest heavily in nitrogen and phosphorus fertilizers to improve yields and feed a growing population. But surprisingly, more than 50% of applied nitrogen fertilizer—and a substantial portion of phosphorus—is never taken up by plants.

Instead, valuable nutrients are lost through:

• Rainfall runoff into rivers and lakes
• Leaching into groundwater
• Volatilization into the atmosphere
• Becoming chemically bound within the soil where plants cannot access them

In other words, farmers often pay for fertilizer that never nourishes their crops.

The consequences extend well beyond the farm. Nutrient losses contribute to harmful algal blooms, degrade water quality, increase greenhouse gas emissions, and represent billions of dollars of wasted agricultural inputs every year.

But what if the problem isn't simply how much fertilizer we apply—but how well the soil holds onto it?

Where Does Fertilizer Go?

Plants absorb nutrients only when they remain available around the root zone.

Unfortunately, many agricultural soils struggle to retain these nutrients, especially after heavy rainfall or irrigation.

Nitrogen is particularly vulnerable. It can dissolve quickly in water and move beyond the reach of crop roots, while phosphorus often binds tightly to soil minerals, making it unavailable for plant uptake.

The result is poor nutrient-use efficiency:

100 kg of fertilizer applied
↓
Only about 40–50 kg is used by crops.
↓
The remaining nutrients are lost through runoff, leaching, gaseous emissions, or become unavailable within the soil.

This means farmers often respond by applying even more fertilizer, creating a costly cycle of diminishing efficiency.

Why Nutrient Loss Matters

Higher production costs

Fertilizer represents one of the largest operating expenses for many farmers. When nutrients are lost before crops can use them, every kilogram of wasted fertilizer directly impacts profitability.

Water pollution

Nitrogen and phosphorus carried into rivers and lakes fuel excessive algae growth, a process known as eutrophication. As algae die and decompose, oxygen levels fall, creating “dead zones” that threaten fish populations and aquatic ecosystems.

Climate impacts

Producing synthetic nitrogen fertilizer is highly energy intensive and contributes significantly to greenhouse gas emissions. Additional nitrogen lost from agricultural soils can also be converted into nitrous oxide (N₂O), a greenhouse gas approximately 270 times more powerful than carbon dioxide over a 100-year period.

Improving nutrient-use efficiency therefore benefits both farmers and the environment.

Biochar Doesn't Replace Fertilizer—It Helps Plants Use More of It

One of the biggest misconceptions about biochar is that it acts like a fertilizer.

It doesn't.

Instead, biochar functions more like a nutrient bank within the soil.

Its highly porous structure creates millions of microscopic pores that retain water and dissolved nutrients. At the same time, biochar's surface chemistry helps attract and hold positively charged nutrient ions such as ammonium (NH₄⁺), potassium (K⁺), calcium (Ca²⁺), and magnesium (Mg²⁺).

Rather than washing away after rainfall, more nutrients remain available where crops need them most—around the root zone.

At the same time, biochar improves soil structure, increases water-holding capacity, and provides habitat for beneficial microorganisms that support long-term soil fertility. Learn more about biochar production and applications in Thailand.

Instead of adding more fertilizer, biochar helps farmers get more value from the fertilizer they're already applying.

What Does the Research Show?

Over the past decade, hundreds of scientific studies have investigated biochar's role in improving nutrient-use efficiency.

Across different crops, climates, and soil types, researchers consistently report that biochar can:

• Reduce nitrogen and phosphorus leaching
• Increase nutrient retention within the root zone
• Improve water-holding capacity
• Enhance microbial activity
• Increase fertilizer-use efficiency

Many studies also report that synthetic fertilizer requirements can be reduced by approximately 20–40% while maintaining comparable crop productivity, particularly in degraded or nutrient-poor soils. The actual performance depends on soil characteristics, crop species, biochar properties, and local management practices.

Rather than replacing fertilizers entirely, biochar helps farmers make every kilogram of fertilizer work harder.

Why This Matters Now More Than Ever

Farmers around the world are facing increasing uncertainty.

Fertilizer prices remain volatile due to global energy markets, supply-chain disruptions, and geopolitical instability. At the same time, agriculture is under growing pressure to improve productivity while reducing its environmental footprint.

Improving nutrient efficiency has therefore become one of the most practical opportunities to lower production costs while supporting more sustainable farming.

Biochar offers a solution that addresses both challenges simultaneously.

By reducing nutrient losses, improving soil health, and extending the effectiveness of applied fertilizer, biochar helps build more resilient agricultural systems.

Turning Agricultural Waste into Better Soil

At Enable Earth, we believe agricultural residues shouldn't be burned or sent to landfill.

Instead, we transform biomass waste into high-quality biochar that helps farmers improve soil health, retain nutrients more effectively, and reduce environmental impacts from agriculture.

By keeping more fertilizer where crops need it—in the soil rather than in waterways—we're helping convert agricultural waste into practical climate solutions.

Our work has also been featured by Thailand's leading business publication, Thansettakij, highlighting Enable Earth's innovative approach to transforming agricultural residues into biochar that supports sustainable agriculture, carbon removal, and Thailand's transition toward a low-carbon economy.

References

1. Goswami, O. (Union of Concerned Scientists). Fertilizer overuse is bad enough—what if you're exposed to multiple pollutants?
2. Thansettakij. Enable Earth and Thailand's biochar innovation for sustainable agriculture and net zero.
3. World Economic Forum. Biochar and fertilizer resilience in a changing world.
4. Agegnehu, G., et al. (2017). The role of biochar and biochar-compost in improving soil quality and crop performance: A review. Applied Soil Ecology.
5. Joseph, S., et al. (2021). How biochar works, and when it doesn't: A review of mechanisms controlling soil and plant responses to biochar. GCB Bioenergy.