Nitrates are an increasing source of tension and controversy. So what’s the problem with nitrates, and is there a better way?
What are Nitrates Anyway?
The earth’s atmosphere is composed of 78% nitrogen. The nitrogen cycle is a global process in which the nitrogen in the atmosphere becomes transformed into nutrients in the soil, which are consumed by plants and animals, then returned to the atmosphere. Nitrogen is essential for all forms of life, and is present throughout the food chain. Nitrates are created when bacteria oxidize the nitrogen in animal waste, converting it into nitrites and nitrates.
The availability of nitrogen governs a broad range of global ecosystem processes in the earth and in marine environments, and human activities have radically altered the natural nitrogen cycle. Of particular concern are the nitrates used as fertilizers in agriculture: they make plants grow faster, but then enter the water supply and have a huge impact on marine ecosystems.
What’s the Problem with Nitrates?
In a natural water system, the low availability of nitrates limits the growth of aquatic plants. When excess nitrates leach into waterways, they cause a surge in the growth of aquatic plants and algae. This excess growth limits the amount of light and oxygen available to other marine life forms, causing fish and other aquatic animals to die or behave abnormally.
Because all nitrates are water-soluble, it is easy for nitrogen-rich farm soil to release excess nitrogen into the ground water, where it becomes problematic for marine ecosystems. The nitrogen cycle is so important and essential for healthy environments, that governments are now seeking to limit the amount of nitrates that can be used in agriculture.
Alternatives to Nitrate-Based Fertilizers
It may be easy to say that farmers simply have to stop using nitrate-based fertilizers for the sake of the environment, but it’s important to provide an alternative that supports the agricultural business model. Here are some of the avenues being explored:
- Genetic modification. One alternative to nitrate-based fertilizers is urea or ammonium-based fertilizers. These compounds are high in nitrogen, but captured at a different phase in the nitrogen cycle, with reduced environmental impact. However, not all plants thrive with these kinds of fertilizers. The pea plant, in particular, thrives with ammonium-rich fertilizers, so some researchers are seeking ways to use the ammonium-loving genes of the pea plant and add them to a range of agricultural crops, to create a broad range of ammonium-loving food crops.
- Improving irrigation technology. Precision irrigation is a promising method of limiting the amount of both water and fertilizer to only the amount needed and taken up by plants in the field. This reduces water runoff as well as limiting the amount of excess nutrients in the soil. Variable-rate irrigation systems that limit water and fertilizer to the precise amount needed, by the crop, by land area, or even by the individual plant, are a promising field of exploration. These systems are driven by precision software and targeted irrigation systems, using micro-sprinklers, drip sprinklers, and even overhead sprinklers. They use GPS, soil and weather monitoring, and automation to target and deliver water and fertilizers. These systems are currently very expensive to install and maintain, but the technology may become more affordable in the coming years.
- Nitrification inhibitors. There are a class of chemical compounds that slow the rate of nitrification, reducing the amount of nitrates in runoff water. They are called nitrification inhibitors, and they are used widely in the United States. Generally speaking, these products slow the rate of nitrification, reducing leaching and runoff. There is a huge range of these products, and most of them have been scientifically proven to be effective at reducing the amount of excess nitrogen in soil and in water runoff. However, there are so many of these products, with such a wide variety of composition and effects, that many of them have been untested. Generally speaking, nitrification inhibitors do not currently affect or improve plant growth or crop production, so they represent an additional expense for farmers, without improving yield. Some of these compounds have been shown to be toxic to other forms of plant and animal life, and German studies have found these inhibitors do enter the marine ecosystem, potentially negating any benefits of reducing nitrates in agricultural soil. Many of these inhibitors are also coated in polymers, so they seem like just another source of plastic in the environment.
- Biostimulants. Biostimulants are a promising new field of research. These compounds are liquids that are high in a range of natural bacteria and microorganisms. Some of the microorganisms enhance the decomposition rate of organic matter, more quickly converting waste into nitrates. Other microorganisms specialize in fixing nitrogen from the air and capturing it in the soil. Biostimulant compounds also include plant-based ingredients that are high in nutrients, or plant growth hormones, or other nutrients, amino acids, and peptides. These products represent a potential solution for excess nitrates, as they rely on natural biological processes to stimulate plant growth and improve plant health. But, again, there is a huge range of these compounds, with a broad number of claims, and few of the specific formulations have been scientifically tested.
There are better, safer, more natural alternatives to nitrogen-based fertilizers. But so far, these alternatives are expensive, or unproven, or may pose other environmental risks. Scientists and researchers are working hard to support farmers and ensure food supply, while protecting our marine environment and promoting sustainable ecosystems. If you want to be part of the next generation with jobs in chemistry, life sciences, and new product development, to help grow a healthier world, contact grapefrute today.