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Limiting nutrients are the elements and molecules that keep ecosystems in check. If these nutrients are released into the natural environment, ecological disaster may follow. Read on to discover more about limiting nutrient compounds and about what your business can do to keep them in check.

Defining a Limiting Nutrient

A limiting nutrient is one of the many types of nutrients that biological materials need to grow within an ecosystem. What makes these nutrients different from others is their relative level of abundance and supply. To put it simply, there is not enough of the limiting nutrient to support ongoing growth on an exponential level, so this growth is restricted.

In this sense, we can think of a limiting nutrient as the “missing piece” of the jigsaw of an ecosystem, or the key that locks and unlocks growth.

For instance, if a specific type of biological organism requires Nutrient A, Nutrient B, and Nutrient C to grow, and all of these nutrients are available in abundant supply, the organism is likely to grow out of control.

On the other hand, if Nutrients A and B are abundantly available, but supplies of C are limited, the plant’s growth will be checked. Nutrient C is the limiting nutrient that maintains the delicate balance of the ecosystem.

Examples of Limiting Nutrients in Nature

There are many different kinds of limiting nutrients found in nature. In fact, as all ecosystems rely upon non-renewable or difficult-to-renew resources to some extent, biomes of all sizes and levels of complexity are affected by limiting nutrients. Here are just a few examples of these nutrients that occur naturally in the world around us.

  • Phosphorus

Phosphorus is perhaps the most familiar limiting nutrient simply because it has become so problematic in recent decades. The element occurs naturally and reacts with oxygen in the air to form phosphates, or PO4. These phosphates then assist in the formation of DNA within cells, as well as the cell membranes that give plant cells their structure. When contaminants such as agricultural fertilizers are released into the water table, phosphate levels reach overabundance and rapid algae growth results. As phosphates are regularly used in fertilizers, this has become a significant issue in areas of large-scale agriculture.

  • Nitrogen

Nitrogen is the most abundant gas in our atmosphere and constitutes 78% of the gas mixture we know as air. With such a natural abundance of nitrogen, it may seem strange to consider such an abundant element a limiting nutrient. However, while organisms require nitrogen in order to function, it is difficult for plant and animal cells to convert the atmospheric gas into a usable form. Bacteria and other simple lifeforms handle the conversion of N2 gas into this usable form, creating a limited supply that keeps ecosystems in balance. Again, industrial and agricultural contaminants can lead to an overabundance of usable nitrogen-based molecules, such as ammonia.

  • Boron

Boron is a micronutrient that helps plants to form cell walls and reproductive structures. It occurs naturally at low levels, but it is often used in fertilizers to eliminate natural growth limits. Such usage needs to be strictly monitored and controlled to prevent damage to local ecosystems.

  • Iron

Iron is a limiting nutrient that is crucial to the growth of phytoplankton. While the other nutrients required by phytoplankton are abundant — or at least relatively abundant — in the ocean, iron is less readily available to phytoplankton colonies, so colony growth is limited according to iron levels. If iron, or an iron-based compound, is released into the ocean, this limitation is removed and phytoplankton can begin to grow unchecked.

Limiting Nutrient Awareness in Agriculture

Limiting nutrients are perhaps most relevant in agriculture. After all, agriculture is all about promoting the efficient growth of highly specialized crops and other plants, so the science surrounding limiting nutrients has been at the heart of agriculture for hundreds of years. Farmers seek to remove the limitations on crop growth by providing an abundance of nutrients that might otherwise be restricted in nature.

While this is not a problem in itself, it does result in issues when these nutrients are transferred into local ecosystems. When this happens, growth levels increase exponentially and ecosystems are no longer balanced. As we have seen from the examples above, rapid and unlimited growth of organisms such as algae and phytoplankton is a direct result of limiting nutrient contamination, and this harms the survival of other organisms within the ecosystems.

Agriculturalists have a responsibility to carefully control their use of limiting nutrients in fertilizers, taking great care to prevent contamination. Deploying stormwater products and drainage systems can prevent fertilizers from being washed into the local water table.

It is also important to monitor levels of limiting nutrients in surrounding ecosystems. While excessive algae growth and other changes do provide an indicator of limiting nutrient overabundance, this sign may come too late to save other organisms within the biome. Conducting regular chemical tests on water and soil samples is a more effective defense.

Limiting Nutrient Awareness in Industry

While industrial facilities may not be working with fertilizer products and other agricultural materials, they may still be using limiting nutrients in the form of phosphates, iron compounds, and other molecules. As a result, facility managers need to remain aware of how these chemicals are being handled and disposed of.

Wastewater treatment must involve physical, chemical and biological processes that prevent any limiting nutrients from escaping into the water table. Meanwhile, the same chemical testing and monitoring should be carried out to reduce the risk of high-level contamination.

Maintaining a Proactive Approach When Handling Limiting Nutrients

If ecosystem damage is traced back to a specific industrial facility, the resulting penalty may be steep. Adopting a proactive approach to chemical spill containment and hazardous material handling is likely to be far more cost-effective for businesses in the long run.

Maintaining ecosystem balance and keeping organic growth under control is the responsibility of all industrial facility owners and agriculturalists across the United States, and limiting nutrients play a crucial role in this.