Crops require fertilizer additions in order to meet the world’s growing demand for food. It is possible for crops to grow larger, faster, and produce more food when nutrients like potassium, phosphorus, and nitrogen are added to the soil with fertilizer. Among the most important nutrients for the growth of all organisms is nitrogen. All around us is nitrogen, which makes up 78% of the air we inhale. There is nitrogen gas in the air, but plants and animals cannot use it. Fertilizers and naturally occurring nitrogen compounds are both viable sources of nitrogen for plants. Excessive fertilizer use, on the other hand, contributes to the emission of greenhouse gases and the eutrophication of our waterways. Scientists are working to find ways to lessen fertilizer’s negative impact on the environment without reducing the amount of food we can produce as a result of its use.
FERTILIZER – WHAT IS IT?
Substances or materials that enhance plant growth are known as fertilizers. Most fertilizers contain nitrogen (N), phosphorus (P), and potassium (K), among other elements (K). The N-P-K ratio is printed on the packaging of fertilizers sold in stores. Lawn fertilizers and agricultural field fertilizers are used all over the world. Three types of fertilizers exist:
- Mineral fertilizers (phosphorus and potash) are mined from the environment and either crushed or chemically treated before being applied to the soil. ‘
- Plant and animal decomposed matter are used to make manure and compost, which are both organic fertilizers.
- There are three types of industrial fertilizers: ammonium phosphate (urea) and ammonium nitrate (ammonium nitrate).
In agriculture, organic and mineral fertilizers have been used for a long time to increase crop yields; industrial fertilizers, on the other hand, are relatively new. Industrial fertilizers are still the most commonly used today.
WHY DO WE NEED FERTILIZERS WITH NITROGEN IN THEM?
In order to grow, all living things (bacteria, plants, and animals) require nitrogen as a nutrient. Many people think of nitrogen as a colorless and odorless gas, but it is in fact the most common form on Earth (about 78 percent of the air we breathe) (N2). Unfortunately, nitrogen gas cannot be utilized directly by plants or animals. The food we eat provides us with the nitrogen we need to thrive. Nitrogen is found in high-protein foods like meat, fish, nuts, and beans. Nitrogen is the most common nutrient to limit plant growth because plants get it from the soil. Without human intervention, nitrogen gas can be converted into nitrogen-containing compounds in two ways: first, by oxidation, and second, by fixation.
Lightning:
Soil is enriched with nitrogen-containing compounds after lightning strikes generate enough energy to break down atmospheric nitrogen.
Nitrogen fixation by living organisms:
nitrogen gas can be used as a source of nutrients by some microorganisms. Nitrogen fixers are the microorganisms that convert nitrogen gas into ammonium (NH4+). There are some soil-dwelling nitrogen-fixing microorganisms, such as those found in legumes and clover.
Even with all this natural nitrogen fixation process of converting nitrogen gas into nitrogen-containing compounds. Low nitrogen levels in soils often still limit plant growth, whether naturally occurring through lightning strikes, performed by specialized microorganisms, or achieved industrially. Nitrogen is a critical component of most commercial fertilizers because it helps plants grow enough food to sustain human populations. Currently, humans are adding as much or more industrially fixed nitrogen (about 150 billion kilograms) to the environment every year than is naturally fixed. Imagine the weight of 24 million full-grown adult elephants in 150 trillion kilograms (330 trillion pounds) of anything!
INDUSTRIAL FERTILIZERS CONTAINED IN NITROGEN
Plants and animals can’t benefit from most Nitrogen on Earth because it’s in the form of nitrogen gas. Nitrogen gas from the atmosphere could be converted into nitrogen-containing compounds that could be used to improve soil fertility in the early 1900s. The Haber-Bosch process is the name given to this method of manufacturing. One of the industrial processes for converting nitrogen into fertilizer components that can be carried out in a laboratory environment. The scientist’s Fritz Haber and Carl Bosch made the discovery, and it bears their namesakes’ initials in honor of them. The Haber-Bosch process fixes nearly all of the nitrogen used in industrial fertilizers.
All over the world, chemical laboratories and large factories perform this industrial nitrogen fixation. For the Haber-Bosch process to work, nitrogen gas and hydrogen gas (H2) must be mixed and then subjected to tremendous pressure (200 times atmospheric pressure). 2,000 meters (6,500 feet) below the surface of the ocean is the equivalent of six Eiffel Towers stacked on top of each other. Once the mixture has been heated to 450°C/842°F, it is pressurized and depressurized. The amount of energy required to maintain these extreme temperatures and pressures is enormous. As much as 1% to 2% of the world’s energy supply is consumed by the Haber-Bosch process every year.
WE USE SO MUCH NITROGEN-CONTAINING INDUSTRIAL FERTILIZER, SO WHAT IS THE POINT?
Short answer: Nitrogen-containing fertilizers help crops grow faster and produce more food. Fertilized land produces more food, allowing for better use of agricultural land. In fact, industrial fertilizers are largely to blame for the rapid rise in global population over the last 60–70 years. Until the widespread use of industrial fertilizers in the 1960’s, it took the Earth’s population 123 years to double from 1 billion to 2 billion. As a result, the Earth’s population doubled in just 45 years (1974–2019). At this point, our food production would be unable to meet the needs of more than half of the world’s population if nitrogen fertilization were not used.
WHAT HAPPENED TO THE NITROGEN FROM NITROGEN-CONTAINING FERTILIZER?
Of course, the plants eat it up! Sadly, that’s not all there is to the story. This Young Minds article, “What is the Nitrogen Cycle and Why is it Key to Life” [3], goes into great detail about the nitrogen cycle’s various reactions. A typical agricultural field utilizes only about half of the nitrogen from fertilizers [4]. Although the fertilizer we use improves the growth of crops, half of the nitrogen it contains is lost. Think about it: we throw away the weight of 165 billion pounds of nitrogen elephants every year! The nitrogen that is lost to the soil can either be released into the atmosphere or be washed away and end up in waterways such as rivers, lakes, and oceans. A wide range of environmental issues are exacerbated as a result of nitrogen runoff.
Why are nitrogen-containing fertilizers bad for the environment?
Several soil microorganisms are capable of converting nitrogen from fertilizers into nitrogen-containing gases, such as nitrous oxide, which are released into the atmosphere (N2O). CO2 emissions from a burning process Another major contributor to global warming is a type of gas that traps heat, much like greenhouse’s roof does to keep its crops safe from freezing temperatures. Carbon dioxide has a warming potential of about 300 times greater than nitrous oxide (CO2).
Eutrophication is a term used to describe the addition of external nutrients (such as excess nitrogen) to waterways.
High levels of nutrients (nitrogen or phosphorus) entering waterways cause changes in the environment’s nutrient status (lakes, rivers, or oceans). One of the most serious consequences is the loss of aquatic life as a result of harmful algal blooms.. Microorganisms, algae, and plants thrive in eutrophic waters, just like they thrive in soil that has been fertilized. Microorganisms and plants that grow rapidly can deplete these waterways of oxygen, turning them into so-called dead zones, which are uninhabitable for aquatic animals. Harmful algal blooms, which are caused by the rapid expansion of toxic algal species as a result of eutrophication, are another possibility. When the water in which cyanobacteria and algae live contains excessive amounts of nutrients (nitrogen or phosphorus), they grow rapidly. Toxins are released into the waterway by these cyanobacteria and algae..
Our agricultural soils require nitrogen, but we don’t want it in our atmosphere or waterways, and we don’t need it. The positive effects of nitrogen fertilization (more food) must be considered in relation to its negative effects (environmental problems) in order to achieve a fair balance [1, 2]. Scientists are currently attempting to achieve this elusive balance in order to better our current predicament.
Do you know of any current research into fertilizer-related topics?
The reduction of the approximately 12 million elephant-worth of industrially fixed nitrogen lost to the atmosphere and waterways is a major objective of fertilizer-related research. This approach is referred to as “improving agricultural nitrogen use efficiency.” Examples of current fertilizer research include the following:
Natural soil nitrogen-fixing bacteria can be encouraged by microbiologists and soil scientists working on ways to improve field conditions. To prevent the loss of nitrogen-fixing microorganisms to the atmosphere or waterways, they are also working on new methods of preventing their growth in the soil (Figure 3). With this combination, the amount of nitrogen-containing fertilizer needed to produce the same crop yield would be reduced.
As microorganisms break down existing fertilizers, scientists are working to create new ones that are more stable in soil. So that nutrients are available to crops for the duration of their lives, these slow release fertilizers release small amounts of nutrients over time. This method still relies on nitrogen-containing fertilizers, but the amount of fertilizer needed and the amount of nitrogen that is lost would be reduced.
To reduce the need for fertilizer, plant biologists are working on genetically engineering crops that require less nitrogen. If these crops are anything like the nitrogen-fixing microorganisms, they’ll be able to fix their own nitrogen gas. In order to achieve the same yield, using less fertilizer on these crops makes sense.
Smart fertilization systems that monitor soil and air conditions in agricultural fields are being developed by computer scientists and soil scientists working together. Small amounts of fertilizer can be added only when necessary with these systems. This reduces the amount of fertilizer used, ensures that fertilizer is applied only where it is needed, and prevents nitrogen from being lost to evaporation.
SUMMARY
Fertilizers help crops grow larger, faster, and produce more food by providing them with essential nutrients like nitrogen. Too much fertilizer, on the other hand, can cause eutrophication and the emission of greenhouse gases. To reduce the amount of fertilizers needed, scientists are currently working to find ways to increase food production while reducing the amount of fertilizers needed.
Glossary
The process of converting carbon dioxide into nitrogen
As a general term, the conversion of nitrogen gas into nitrogen-based compounds. Lightning strikes, specialized microorganisms, or industrial processes can all be used to fix nitrogen.
The Haber-Bosch procedure:
One of the industrial processes for converting nitrogen into fertilizer components that can be carried out in a laboratory environment. Fritz Haber and Carl Bosch, who made the discovery and gave it its name, are credited with its discovery.
Climate Change: GHGs
In the same way that a greenhouse’s roof retains heat to keep the plants inside safe from the cold, certain gases in the atmosphere do the same.
Eutrophication:
High levels of nutrients (nitrogen or phosphorus) entering waterways cause changes in the environment’s nutrient status (lakes, rivers, or oceans). In addition to the loss of aquatic life, harmful algal blooms are a major repercussion.
Blooms of Toxic Algae:
When the water in which cyanobacteria and algae live contains excessive amounts of nutrients (nitrogen or phosphorus), they grow rapidly. Toxins are released into the water by the cyanobacteria and algae.
