How to Boost Soil Fertility and Crop Yield with Granular Ammonium Sulfate: A Science-Backed Guide

How to Boost Soil Fertility and Crop Yield with Granular Ammonium Sulfate

In global agriculture, optimizing soil health and maximizing yield are top priorities for farmers and agronomists alike. Among nitrogen-based fertilizers, granular ammonium sulfate (AMS) stands out due to its high nutrient content, balanced nutrient profile, and proven performance across diverse crops and climates.

1. Key Composition and Properties of Granular Ammonium Sulfate

Granular AMS typically contains 21% nitrogen (N) and 24% sulfur (S), making it a dual-purpose fertilizer ideal for addressing both N deficiency and sulfur-deficient soils—especially in regions like Southeast Asia, North America, and parts of Europe where sulfur depletion is rising due to reduced atmospheric deposition from cleaner air policies.

2. Enhancing Soil Structure and Microbial Activity

Unlike some urea-based fertilizers that can increase soil pH over time, AMS maintains a slightly acidic reaction (pH ~5.5–6.0), which helps prevent alkalinity buildup in calcareous soils. Field trials in China’s Huang-Huai region showed that consistent use of AMS improved aggregate stability by up to 18%, leading to better water infiltration and root penetration.

3. Optimizing Application for Maximum Yield Gains

For best results, apply AMS at planting or early vegetative stage (V3–V5 for corn). Studies from the University of Illinois indicate that splitting applications—half at planting, half during tillering—can boost grain yields by 7–12% compared to single-application methods. For rice, broadcast application followed by light irrigation ensures even distribution without leaching losses.

4. Real-World Applications Across Crops

In Brazil, soybean farmers using AMS reported a 15% increase in protein content and a 9% higher yield when combined with inoculant treatments. Similarly, in Kenya, maize growers saw 11% more biomass and fewer yellowing symptoms in leaves after switching from urea to AMS in sandy loam soils.

5. Synergistic Use with Other Fertilizers

AMS pairs well with potassium chloride (KCl) for balanced NPK applications. However, avoid mixing with lime or phosphate rock, as this may reduce solubility. A common blend used in Australian wheat farming includes 60% AMS + 40% KCl, delivering optimal nutrient ratios while minimizing environmental impact.

6. Common Mistakes and Best Practices

Avoid surface broadcasting on dry soil—it increases volatilization loss. Always incorporate into soil within 24 hours of application. Also, do not exceed 150 kg/ha per season unless soil tests confirm need. Overuse can lead to salt stress, especially in low-rainfall areas.