As the economic pressure on farmers rises, improving returns becomes a vital necessity. 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 throughout the world 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 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. Europe has the highest production standards all over the world, meeting the social, environmental and health requirements of our society - today as well as tomorrow.
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 so cannot provide phosphorus in an available form for plant use.
Many of the sources of phosphorus are sedimentary deposits on old ocean floors
which were later uplifted by upheavals of the earth. These deposits can also contain
many other minerals and so contamination with heavy metals such as cadmium can
be an issue.
The other sources of phosphate rock are from igneous rock deposits, from molten
lava, having volcanic origin. This rock is in general very low in contaminants. Yara´s mines in Finland produces this type of phopate rock.
To produce a phosphorus fertilizer, the rock is treated with acid; sulfuric, phosphoric or nitric. Each method has its advantages and constraints. The sulfuric acid route produces a low phosphorus fertilizer – single superphosphate - which is half gypsum. The use of phosphoric acid produces a higher concentration phosphorus fertilizer.
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:
The limitation of this process is that the phosphate content of the fertilizer cannot exceed the nitrogen content.
Most potassium used in fertilizer production is taken from natural deposits of potassium chloride. The mined material is crushed and purified by the removal of rock particles and salt. Deposits of potassium sulfate and potassium nitrate are more rare, but when used, are treated in a similar manner.
Deposits of potassium chloride are also reclaimed from the concentrated salts of places like the Dead Sea.
The further content of minerals in the fertilizers are added during the production process, prior to the final prilling or granluation.
For the fertilizer to have the desired physical properties is important for the farmer in order to succeed in his spreading of the product in an even and controlled manner. The most important properties are:
Yara fertilizer plants are located all over Europe, in close vicinity to seaports and rivers to enable efficient transportation: Montoir, Ambès and Le Havre in France, Brunsbüttel and Rostock in Germany, Tertre in Belgium, Sluiskil in the Netherlands, Ravenna in Italy, Porsgrunn and Glomfjord in Norway to name only a few.
Yara’s fertilizer factories run 24 hours 7 days a week. They only stop once in a while for maintenance work and installation upgrades. Huge storage areas hold sufficient stock to ensure continuous deliveries and compensate for demand variations.