Understand fertiliser types and match to crop nutrient needs by growth stage

Crop nutrient requirements vary across growth stages, and mismatched fertiliser type or timing reduces nutrient uptake efficiency. Inorganic fertilisers, such as ammonium nitrate (AN), calcium ammonium nitrate (CAN), urea, and urea ammonium nitrate (UAN), are commonly used in European agriculture. These are available as dry granules, liquids, or slow-release formulations, with NPK ratios like 16-16-10 or 20-20. Soil pH significantly affects nutrient availability, as extreme values immobilize nutrients. Fast-acting forms like liquid and dry fertilisers are prone to leaching, while slow-release types reduce losses. For maize, nitrogen demand peaks during rapid vegetative growth, requiring timely application of quick-release forms to avoid leaching. Ammonium-based fertilisers (NH₄⁺) are less leachable and enhance root uptake in cool soils, while nitrate-based forms (NO₃⁻) offer rapid availability but require precise timing. Urea provides flexibility but needs incorporation or inhibitors to reduce volatilisation. Best practice involves aligning fertiliser choice and timing with crop demand, using soil testing, crop models, and real-time data to improve nutrient use efficiency, reduce environmental impact, and support sustainable, profitable farming.