Avoid Over-Fertilizing: How Soil pH Affects Ammonium Sulfate Efficiency and Smart Management Tips

Why Soil pH Matters More Than You Think for Ammonium Sulfate Efficiency

You’ve probably seen it: crops that don’t grow as expected, even when you apply what seems like the right amount of fertilizer. It’s not always about quantity—it’s often about soil chemistry.

Ammonium sulfate (NH₄)₂SO₄ is a powerful nitrogen-sulfur source with 20.5% nitrogen and 23% sulfur, making it ideal for boosting crop yields—especially in sulfur-deficient soils. But here’s the catch: its effectiveness drops sharply if your soil pH isn’t in the optimal range (6.0–7.5).

How Soil pH Controls Nutrient Uptake

When pH falls below 6.0, aluminum and manganese become more soluble—and toxic to roots. At the same time, ammonium ions (NH₄⁺) bind tightly to clay particles, reducing their availability. In alkaline soils (pH > 7.5), ammonia volatilization increases dramatically—meaning up to 30% of your applied nitrogen can be lost to air before plants absorb it.

“Field trials from the USDA Extension Service show that adjusting soil pH to 6.5–7.0 improves ammonium sulfate uptake by 40–60%, especially in corn and wheat.” — Dr. Lena Zhang, Agronomy Specialist

Over-application without testing is risky—not just environmentally, but economically. Excess nitrogen leads to leaching, runoff, and even nitrate contamination of groundwater. That’s why many farmers now use soil testing kits or work with agronomists to create precise nutrient plans.

In one case study from Brazil, a soybean farmer who switched from blanket fertilizing to pH-adjusted ammonium sulfate application saw a 22% yield increase over two seasons—with no additional input costs.

So yes, you can still use ammonium sulfate safely and effectively—but only if you understand your soil first.

If you've ever wondered why your fertilizer didn't work as planned, we'd love to hear your story. What challenges have you faced with nitrogen applications? Share your experience in the comments below—or reach out directly for a free soil analysis consultation.