As the economic pressure on farmers rises, improving returns becomes vital. Optimizing farm inputs is a way to cut costs while controlling returns. One of the most important farming inputs is mineral fertilizer. It originates from various sources worldwide and can be of variable quality.
The mechanical quality of fertilizer is key for spreadability, precise application, low environmental impact, and high return on investment. In many cases, simply taking a handful of fertilizer gives a first idea: dust and crushed granules indicate low quality, while the homogeneous size and smooth surface stand for superior spreadability.
Mineral fertilizers also shall be pure nutrients, free of additives and pollution. And their environmental footprint, both at production and application, shall be as low as possible. Ensuring high quality goes along with continuous investments in people, technology, and organization.
In a modern plant, nitrogen fertilizer is produced from natural gas. In several transformation steps, natural gas, essentially methane, is upgraded by combination with nitrogen from the air to form nitrogen fertilizer. 80% of the gas is used as feedstock for fertilizer, while 20% is used for heating the process and producing electricity.
Based on the two main end products, ammonium nitrate and urea, different fertilizer types are manufactured by mixing with ingredients such as phosphorus and potassium to form NPKs, dolomite to form CAN, or by mixing urea and ammonium nitrate solution to make UAN.
Phosphorus fertilizers are produced by acidulating phosphate rock. By itself, phosphate rock is not soluble and cannot provide phosphorus in an available form for plant use.
To produce a phosphorus fertilizer, the rock is treated with acid; sulfuric, phosphoric or nitric. The third manufacturing process is to use nitric acid to acidulate the rock phosphate. This process is a cleaner process with no waste products and produces two fertilizers:
- Nitrophosphates which are combined with potassium to produce the complex NPK fertilizers such as YaraMila.
- Calcium nitrate (from the nitric acid combining with the calcium in the rock phosphate) as found in the YaraLiva range.
Most potassium used in fertilizer production is taken from natural deposits of potassium chloride. The mined material is crushed and purified by rock particles and salt removal. Deposits of potassium sulfate and potassium nitrate are more rare but, when used, are treated similarly.
Deposits of potassium chloride are also reclaimed from the concentrated salts of places like the Dead Sea.
For the fertilizer to have the desired physical properties is important for the farmer to spread the product in an even and controlled manner. The most important properties are:
- Free-flowing in nature.
- Hard granules or prills.
- Consistent in particle size.
- Easily spread – ensuring even distribution patterns.
- Packed with as many nutrients as possible in each particle.
- Quickly dissolving when in contact with moist soil.
- Free from undesirable contaminants.