Nitrogen, Nitrogen Everywhere, Nor a Drop to Eat!
Nitrogen, Nitrogen Everywhere, Nor a Drop to Eat!
Nitrogen represents one of agriculture’s most critical yet paradoxical challenges. The atmosphere contains abundant nitrogen gas that plants cannot access directly, yet feeding the world requires transforming this inert atmospheric resource into useable forms. Modern agriculture depends on both synthetic nitrogen fertilizers, produced through the energy-intensive Haber-Bosch process, and natural biological fixation systems that have sustained ecosystems and our planetary life support for billions of years. In this post, we want to dive into these approaches and how agriculture can maintain productivity while progressively improving sustainability and resilience, and how Fish Brew can play a role in meeting those goals. Although we are mostly focused on agriculture in this discussion, all of these factors are at play for any setting that requires nitrogen fertilizer such as your garden or lawn.
Nitrogen: The Essential Nutrient
Nitrogen constitutes approximately 78 percent of our atmosphere, yet this vast reservoir exists in a chemical form that virtually all plants cannot access directly. When plants have adequate nitrogen, they develop deep the green coloration characteristic of vigorous foliage, sturdy stems, and strong growth because nitrogen forms fundamental building blocks of life, such as proteins, chlorophyll, and nucleic acids (DNA and RNA). This makes nitrogen a key nutrient in driving global food productivity, both in natural systems and even more so in modern agriculture.
The challenge for modern agriculture lies in the mobility of nitrogen through soil and water environments. The objective is to deliver just enough nitrogen to maximize crop production while minimizing losses to water and the atmosphere. When nitrogen is not used effectively, it leaches into groundwater or surface runoff as nitrate (creating additional problems for drinking water supplies and downstream aquatic ecosystems), or nitrogen escapes to the air as ammonia or nitrous oxide (a potent greenhouse gas). Both source and method of nitrogen supplementation can impact success at achieving productivity while maintaining sustainability.
Synthetic Nitrogen Fertilizers: Industrial Ease with Diminishing Returns
The Haber-Bosch process, developed over a century ago, transformed agriculture by enabling the industrial conversion of inert atmospheric nitrogen gas and hydrogen gas into ammonia. Once ammonia is produced, it can be modified into other forms such as ammonium sulfate, ammonium nitrate and urea depending on the particular application.
The short-term advantage of synthetic fertilizers is significant and explain their global dominance. Synthetic NPK fertilizers can deliver precise nutrients and provide immediate nitrogen availability to correct deficiencies rapidly. Their consistency and potency make them extremely convenient for large monocropping operations with many acres under cultivation. Economically, synthetic fertilizers are tied to fossil fuel pricing and remains the most affordable nitrogen sources available globally.
The disadvantages, however, are hidden in the long term. Repeated use of ammonium-nitrogen sources causes soil acidification (reduction in soil pH) and depletes micronutrients that may not be included in basic synthetic NPK fertilizers. While soil degradation will impact future soil fertility, there are other environmental impacts to consider too.
Synthetic forms of nitrogen fertilizer are highly mobile in soils. High nitrogen surface runoff contributes to eutrophication and anoxic dead zones in aquatic and marine ecosystems and nitrate contamination in groundwater from leaching fertilizers and can make water dangerous to drink; as excessive nitrate interferes with the blood’s ability to carry oxygen. Alternatively, up to 60 percent of applied urea can be lost as ammonia gas or even worse, in anaerobic waterlogged soils ammonia can be released as nitrous oxide which is a greenhouse gas approximately 300 times more effective at trapping heat than carbon dioxide.
Recent fighting in the Middle East has highlighted risks in the synthetic nitrogen supply chain and brought them into mainstream consciousness. Like the fossil fuels their production depends on, the global production of nitrogen fertilizers is concentrated in certain regions and can easily get disrupted. Nearly 30% of globally traded ammonium and 25% of globally traded urea is reported to be produced in the Middle East. This leads to a spike in energy costs as well as fertilizer pricing during times of conflict in these regions.
Luckily synthetics are not the only path.
Natural and Organic Nitrogen Inputs: Building Soil While Feeding Plants
Animal-based sources have served agriculture for millennia and continue as major nitrogen inputs. Livestock manure and composted livestock manure comes to mind immediately, but others such as blood meal, feather meal, and fish hydrolysate are other natural nitrogen rich inputs. Each with various levels of NPK and micronutrients to bring to the soil.
The disadvantages to these types of fertilizers are that they are often less concentrated in comparison to synthetics so they may require higher volume applications to achieve the same levels of nitrogen and therefore can create logistical and labor constraints. Also, the some of these products may release nutrients slower, making for deficiencies during key growth times in heavy feeding crops (or crops bred to utilize fast acting potent synthetic fertilizers). This disadvantage of being “too slow” on nitrogen availability may also be an advantage. Research has shown that over-fertilization with fast acting nitrogen fertilizers can increase amino acid levels in plant tissues and end up increasing pest pressure leading to lower yield.
The additional advantages of these inputs will outweigh the disadvantages in the long term for many because the benefits of natural organic nitrogen fertilizers extend well beyond the simple provision of nitrogen itself. The most significant advantage involves their contribution to long-term soil fertility and structure. Unlike many synthetic fertilizers that can degrade soil over time through acidification and micronutrient depletion, natural organic fertilizers build soil while feeding plants. The organic matter component of these materials becomes incorporated into the soil, improving its physical structure, water-holding capacity, and biological activity. Over multiple seasons and years of use, these improvements compound, creating increasingly fertile and productive soils that require less intensive management to maintain productivity.
Enhanced nutrient efficiency represents another crucial advantage of organic nitrogen sources. The slow release of nitrogen from organic materials reduces leaching and extends availability over the whole growing season. Rather than providing a large pulse of available nitrogen that the plant can uptake only partially before the excess leaches away or escapes to the atmosphere, organic sources deliver nitrogen gradually in closer synchronization with plant demand. This improved efficiency reduces the quantity of nitrogen that must be applied to achieve desired productivity levels, lowering the overall input costs and reducing environmental losses. Additionally organic fertilizers promote the development of beneficial soil microorganisms, such as bacteria and fungi, which help break down organic matter and create a living and productive soil ecosystem.
Natural organic fertilizers represent a fundamentally sustainable approach to nitrogen provision that integrates ecological principles into agricultural practice. From an environmental perspective, the environmental footprint of organic fertilizers can vary depending on the source and application. But they are not as directly reliant on fossil fuels as nitrogen produced with the Haber-Basch process and are often created by recycling waste materials that would otherwise require disposal. For example, Fish Brew Fish Hydrolysate Fertilizer is created from processing scraps and mortalities at our farms that would normally be thrown away. For farmers concerned with long-term soil health and environmental stewardship, organic nitrogen sources align with these values while maintaining productivity.
Nature’s Way: The Nitrogen Cycle
Although as humans we are looking to maximize food production to feed an ever-growing population through aggressive interventions, nature has operated a sophisticated nitrogen cycling process for billions of years. Approximately 90 percent of natural nitrogen fixation (converting nitrogen gas to inorganic nitrogen compounds) occurs through specialized bacteria and blue-green algae, with much smaller contributions from lightning and other abiotic processes. These bacteria and cyanobacteria are able to do this conversion thanks to specialized enzymes called nitrogenase that is able to catalyze the reaction; converting N2 to ammonia (NH3).
One of the more important and better studied examples of nitrogen fixing with regard to agriculture is the symbiotic partnership of Legumes and Rhizobia. Legumes are a group of plants that include important food and animal feed crops like soybeans, peas, beans, and peanuts. These plants form mutualistic relationships with bacteria called rhizobia. The rhizobia are attracted to the roots by chemical signals and take up residence in specializes structures called nodules where they will live and provide much needed nitrogen to the plant. In return the plant provides some needed nutrients to the bacteria as well as an optimal environment for bacteria to perform its nitrogen fixing duties. Oxygen disrupts the function of nitrogenase, so the bacteria require a low oxygen environment, but not too low that the bacteria are not able to respirate. A hemoglobin like pigment called leghemoglobin scavenges oxygen molecules in the nodule and provides a goldilocks environment for the rhizobia. And just like hemoglobin in blood, a functioning nodule will have a reddish or pink color indicating that the leghemoglobin is doing its thing.
Legumes and their symbionts are amazing in their ability to synthesis nitrogen essentially from thin air. This is part of the reason that these plants are known as being the best source of plant-based protein for humans and animals (proteins are roughly 16% nitrogen). The quantity of nitrogen fixed by legumes is enough to meet the needs of the legume plant itself and to potentially enrich the soil for subsequent crops. However, there is a misconception that legumes will produce significantly more nitrogen than the plant requires. During the growing season plants accumulate this nutrient in their tissues, building substantial quantities by the time flower begins. At the moment of maximum content, the farmer can cut down the plant to the soil level to allow it to decompose in place. This will release organic nitrogen for the next crop to access. If the crop and plant tissue were to be removed from the system so will most of that additional nitrogen.
As with any natural organic nitrogen or synthetic organic nitrogen form, steps will need to happen in the soil to make that ammonia or ammonium accessible to the plants.
Ammonification and Nitrification: Breaking it all down
The plant material that is left behind is broken down by microbes, and one result is the ammonification of the proteins. That leaves behind ammonia and ammonium in the soil which is not the preferred form for plant uptake. Nitrifying bacteria in the presence of oxygen is then needed covert ammonia (NH3) to Nitrate (NO3-) which can then be taken up and used by the plant. A diverse range of soil microbes will aid in this break down. While most healthy soils will have a good reservoir of these microbes, commonly disturbed soils from tillage, pesticide use, herbicide use, compaction, or chemical fertilizer applications may benefit from applications of a biological amendment like Fish Brew Rise & Thrive to jumpstart this process. Soils without thriving microbial communities can slow nitrogen availability despite nitrogen-containing compounds being present in the soil.
Conclusion:
Nitrogen management represents one of agriculture’s defining challenges and opportunities. While synthetic fertilizers remain essential for meeting global food security, their vulnerabilities to geopolitical disruptions, energy costs, and environmental impacts demand complementary approaches. The most sustainable path forward integrates synthetic and organic sources strategically: weaning away from synthetic forms, and only using them in targeted, responsible applications while systematically building soil fertility and microbiology through local recycled organic amendments and other regenerative techniques. Agriculture’s ability to optimize all available nitrogen sources while minimizing environmental losses will ultimately determine both productivity and planetary health.