Ammonia in agriculture: The engine of plant growth

About 50 percent of the world’s food production depends on mineral fertilizer application. Due to the increasing world population and changing diets to more meat, there is a constant growth in fertilizer consumption. One of the key players: Ammonia. Ammonia binds air borne nitrogen and makes the most important crop nutrient, nitrogen, available for nitrogen fertilizer production. As an important base material for fertilizers, ammonia literally helps to put our food on the table.

Today, roughly 80% of the annually produced ammonia is used for fertilizer production. Fertilization improves plant nutrition, promotes plant growth, improves crop quality, and ultimately maintains and even enhances soil fertility.

Ammonia and its role in plant nutrition

To grow strong and to grow fruits, plants require nutrients like nitrogen, potassium, phosphorus, magnesium, sulfur, and calcium. However, just like humans, all plants are different and require specific amounts of nutrients, depending on their type and the location and soil they grow in. Agricultural crops may require about 20-350 kilograms of nutrients per hectare over the course of their development. But the necessary nutrients are often missing in the soil due to different factors.

• Either they are not naturally present in sufficient quantities or

• they are displaced by leaching or removed by harvesting.

In this case, only the supply of plant nutrients through fertilization makes it possible to compensate the lack and guarantee future cultivation.

More is less: tk’s strategy against over-fertilization

With the intention to feed a growing world population and an increasing demand in the food supply, over-fertilization often affects the soil, surface water, and groundwater negatively due to dispersion of mineral use and nitrogen excess. To avoid this, farmers are faced with the challenge to keep their ecological footprint as small as possible while not losing any of the potential harvests. Farmers need a fertilizer with tailor-made nutrient composition and nutrient release profile over time exactly to the needs of the crop under the given climatic and soil conditions. In practice, this means for the fertilizer producer to develop fertilizers that feed plants more efficiently while at the same time causing lower losses/emissions during application and reducing the consumption of raw materials.

In fact, the controlled release of nutrients reduces the emission of nitrates to the groundwater and optimizes the use of the fertilizers and their application. The fertilizer with the highest nitrogen content is urea with 46%. Treating urea fertilizers with urease inhibitors or covering fertilizers with coating material allows long-term release of nutrients to the ground over the entire period of crop growth.

For the covered fertilizers the proper selection of the coating material is decisive for the environment. That’s why thyssenkrupp offers a coating with PLA (Polylactic Acid), which has the great advantage that it is fully biodegradable in comparison to other polymer-based coating materials, which leads to an increase of microplastic in the soil and groundwater. Furthermore, PLA can be produced from renewable sources.

Less is more: Ammonium nitrate reduces emissions

Environmental protection does not play a role only in fertilizer application but also in its production. A major impact is always the CO2 emission during production.

If based on green ammonia,the carbon footprint of ammonium nitrate or calcium ammonium nitrate (CAN) fertilizer per kilogram of product and per kilogram nitrogen delivered to the soil is amongst the lowest of any fertilizer product available.

CAN (calcium ammonium nitrate) is a fertilizer with a nitrogen content of 25 - 28%, perfectly suited to the European acidic soil and colder weather conditions. To prevent exploitation of the soil and meet the plants needs, half of the nitrogen in ammonium nitrate fertilizer is quick release nitrogen, which is immediately available to the plants. The other half is slow release nitrogen to form an effective balance in the plant nutrition.

Additionally, calcium is beneficial to the plant and the soil. It increases plant size and protects plants from developing deformed leafs and buds. A pleasant side effect: It helps farmers to protect their soil as calcium effectively regulates the soil’s pH and promotes soil life.