Every season, millions of producers in Latin America open a bag of urea and apply it to their crops. Some do it based on technical recommendations, others because "that's how it's always been done on this farm." Most do not know exactly how much of that nitrogen will reach the root, but on average, crops absorb only about 50% of the nitrogen applied through fertilizers, and the rest is lost to the atmosphere, groundwater, or is trapped in microbial processes.
As we have been discussing in previous topics, the soil is what truly transforms all the inputs you incorporate into the crop into production; therefore, to delve deeper into this topic, I will talk about one of the most needed products by plants, which is nitrogen, and which is easily lost in tropical soils. If you apply 100 kg of nitrogen per hectare, half may be working for your crop, while the other half may be flying away, leaching, or simply unavailable. Considering that when the price of a bag of urea rises, as has been happening in recent years, that inefficiency becomes a production cost that is hard to bear.
Nitrogen (N) is the nutrient that generates the most response in crops and at the same time the one that is most lost and the one that most depends on conditions that vary from one plot to another, from one season to another, from one soil to the neighboring one. Understanding how it works is not an academic exercise. It is a direct economic decision regarding the profitability of your production.
What the bag says and what actually reaches the root
When you go to the distributor and buy nitrogen fertilizer, the numbers on the label are clear: urea says 46-0-0, ammonium sulfate says 21-0-0, DAP says 18-46-0, ammonium nitrate says 26-0-0 or 30-0-0. These numbers indicate the percentage of total nitrogen in the product, and this is where the most costly confusion in agriculture begins, as many producers interpret that number as the nitrogen that their crop will absorb. The reality is that this percentage is what the bag contains, not what reaches the plant.
Each source carries nitrogen in a different form. Urea carries it as urea CO(NH₂)₂, which is the most concentrated source and the lowest price per unit of N, but also the most susceptible to loss if not managed properly. Ammonium sulfate carries it as NH₄⁺ (ammonium), which is more stable in the soil and has an additional benefit: it provides sulfur. Nitrates (calcium nitrate, potassium nitrate) carry N already in the form of NO₃⁻, which is directly usable by the root but is also the most mobile form and easily lost with water.
What happens between application and absorption by the root is a process that depends on the soil, climate, timing of application, and the biology of the system. Under non-optimal conditions, a significant portion of that nitrogen never reaches where it should. In the soil, nitrogen does not stay still or in a single form. It is present in organic matter, in microorganisms, and in the inorganic forms that roots actually take up, which are ammonium (NH₄⁺) and nitrate (NO₃⁻). The key point is that between 75% and 90% of the nitrogen that plants absorb has previously passed through microorganisms. Soil life is the engine that transforms nitrogen into something useful. Without it, any source of N loses efficiency before reaching the root.
Four windows through which money escapes
For a producer, the nitrogen problem is not uncommon; they easily see it in fields where fertilizer was applied and the crop did not respond as expected. They see it in leaves that yellow from the oldest to the youngest during the cycle. And it is seen at the end of the season when the yield does not justify what was spent on inputs. There are four concrete reasons why that N left before your crop could take it.
The first is volatilization, or how N evaporates before it rains. Urea is the most used nitrogen source in Latin America due to its high N content and comparatively low price. The problem is that when left on the soil surface, it reacts with moisture and temperature and releases ammonia gas (NH₃) that goes into the air; urea needs incorporation or immediate irrigation. In Andisols with coffee crops, studies in Colombia recorded accumulated losses of up to 35% of the applied urea in just 20 days. So you apply the bag on a Monday morning. The soil is dry. No rain is forecast. You pass by the plot on Tuesday, Wednesday, and see the urea still there. On Thursday, the wind disperses it a bit. On Friday, a rain of just 5 mm arrives, insufficient to incorporate it deeply. After 15 days, you check that the crop shows no response to the nitrogen you applied.
The second is leaching, or how N goes with water. Nitrate (NO₃⁻) does not stick to the soil. It moves with rain or irrigation water to deeper layers, out of reach of the roots. In sandy soils or those with low nutrient retention (low CEC), located in areas of frequent and intense rains, losses can reach between 100 and 200 kg of N per hectare per year. Therefore, if you applied nitrogen just before a heavy rain, or over-irrigated shortly after, and the crop did not respond, the N passed by. Additionally, that lost nitrate can contaminate groundwater or nearby water sources.
The third is denitrification, or how N turns into greenhouse gas. In waterlogged soils or areas with excess moisture, such as flooded rice fields, poorly drained areas, or during intense rainy seasons, soil bacteria convert nitrate into gases that are released into the atmosphere, such as nitrous oxide (N₂O), nitric oxide (NO), and nitrogen gas (N₂). You do not see it directly, but the impact is double because N is lost, and N₂O has a global warming potential 265 times greater than CO₂.
Finally, there is immobilization, or how N becomes "sequestered" by undecomposed organic matter. If you incorporate crop residues with high carbon content and low nitrogen, such as corn stover or cereal remnants, the microorganisms responsible for decomposing them need so much N for that work that they take it from the soil, directly competing with the roots of your crop. The N gets trapped in microbial biomass and is unavailable for weeks or even months.
Knowing these four loss pathways allows for concrete decisions about when to apply, in what form, and what protections to consider. Nitrogen must complete a cycle, but in agronomy, we must seek to maximize it by knowing the most appropriate moments to avoid significant losses and costs that are not utilized as they should be.
As we already addressed in our blog We spend millions on fertilizing... but who is processing those nutrients?, which you can read here, the efficiency of any nitrogen fertilizer depends on having active microorganisms in the soil capable of transforming that N into forms that the root can absorb. Without that active biological base, even the best nitrogen source loses effectiveness before reaching the plant.
The fragility of urea prices
There is a factor that Latin American producers cannot control but that directly impacts their costs, which is that most countries in the region import almost all of their nitrogen as urea or derived sources. Latin America depends on about 85% of imports to meet its demand for N, P, and K. No food-producing country in the region can isolate its production costs from international fertilizer markets.
Colombia is a clear example; since the late 1970s, the country has not produced urea industrially. In 2024, it imported 2.13 million tons of fertilizers, with urea being the most valuable input (USD 295 million), mainly from Russia, China, and the United States. The problem is that these markets change, as happened in 2022 when the Russian invasion of Ukraine drove nitrogen fertilizer prices to historic highs. In 2025, urea prices rose another 25%, driven by the increase in natural gas, the raw material for the Haber-Bosch process used to produce urea, and export restrictions from China. And in 2026, the conflict in the Middle East generates new upward pressures, with risks of lower availability and longer delivery times.
Colombia is a clear example; since the late 1970s, the country has not produced urea industrially. In 2024, it imported 2.13 million tons of fertilizers, with urea being the most valuable input (USD 295 million), mainly from Russia, China, and the United States. The problem is that these markets change, as happened in 2022 when the Russian invasion of Ukraine drove nitrogen fertilizer prices to historic highs. In 2025, urea prices rose another 25%, driven by the increase in natural gas, the raw material for the Haber-Bosch process used to produce urea, and export restrictions from China. And in 2026, the conflict in the Middle East generates new upward pressures, with risks of lower availability and longer delivery times.
Strategies that reduce losses and improve returns
Efficient nitrogen management is not solved by buying more bags. It is resolved by making better decisions about when, how, and in what form to apply it. Consider the following strategies to maximize the nitrogen your crop utilizes:
Fractionating the dose is the measure with the most immediate impact. Instead of applying all the N at once, it is distributed over two or three moments that coincide with the stages of highest demand of the crop. Well-executed fractionation can increase nitrogen use efficiency by 20 to 30%, and under specific soil and crop conditions, the results are even more pronounced. Experiments with rice documented in Colombia show that fractionating one-third before planting and two-thirds at the beginning of panicle formation increased agronomic effectiveness by up to 44% compared to a single application. The principle is simple: the fertilizer must coincide with the moment when the root system is active and can take it, not just with the day when logistics allow it.
Choosing the right source according to the soil and crop. In acidic soils (pH less than 6.0), ammonium volatilization is lower, and ammoniacal sources like ammonium sulfate work well. In neutral or alkaline soils, unprotected urea is more susceptible to loss. Urea coated with sulfur or fertilizers with nitrification inhibitors like DMPP are alternatives that in studies conducted in tropical soils in Brazil achieved good results, as nitrification inhibitors retained up to 60% more ammonium and reduced nitrate concentrations, decreasing losses without affecting N availability for the crop. Under high humidity conditions, dual inhibitors can increase corn yield by up to 9% and reduce volatilization by up to 68% compared to conventional urea. The additional cost of fertilizer with an inhibitor is justified when the risk of losses is high.
Incorporating fertilizer and synchronizing it with irrigation. Burying the fertilizer instead of leaving it on the surface can reduce volatilization by 40 to 60%. In systems with advanced irrigation, fertigation allows applying dissolved N in small, frequent doses directly in the root zone, which can reduce total losses by up to 40% compared to conventional surface fertilization. It is not always possible in all crops or with all equipment, but where infrastructure exists, the impact on efficiency is significant.
Integrating organic sources and biological fixation. Organic materials—composted coffee pulp, chicken manure, pig manure, cattle manure—provide slow-release N and improve microbial activity that makes mineral N availability possible. But the most powerful long-term strategy is incorporating legumes into the production system. A global meta-analysis published in 2024 in the Journal of Agronomy and Crop Science, which analyzed data from 1980 to 2018, found that legumes obtain on average 68% of their nitrogen directly from atmospheric biological fixation, with forage legumes reaching up to 75%. That is nitrogen you do not buy, do not transport, and does not depend on the price of natural gas in Russia. Rotations with soybean, cowpea, crotalaria, or beans reduce dependence on synthetic fertilizers while improving soil structure at the same time. Studies conducted in Colombian soils showed that rotation with soybean combined with green manures of crotalaria outperformed nitrogen fertilization alone. The combination of adjusted mineral fertilization with leguminous rotations represents the most comprehensive and economically resilient strategy against market volatility.
The N that is paid for but does not produce
Data from farms I have supported reveal a gap that is not visible without systematic records; on farms with similar nitrogen applications per hectare, production costs can vary by up to 30% depending on the timing of application and soil conditions in each plot.
The cause is almost never in the amount of N applied. It is in the real efficiency of use. A plot with high microbial activity, good pH, and proper fractionation can achieve the same yield with 20 to 30% fewer nitrogen units than a plot where fertilizer is applied all at once, on dry soil, without incorporation. The difference does not appear in purchase records, although both producers bought the same bag at the same price; at the end of the cycle, when calculating the cost per kilo of product obtained, the difference is evident.
Another pattern I have observed is that in the plots where the greatest loss is recorded, they are not necessarily the most neglected; they are the ones with high pH soils, high susceptibility to temporary waterlogging, or that receive most of the N in a single application at the beginning of the cycle. Cross-referencing pH data by plot, organic matter history, rainfall regime, and thermal floor allows you to identify exactly where on your farm the urea is working and where it is escaping.
Nitrogen is the most studied nutrient in the world and remains the most poorly applied in the field. The difference between the two is not knowledge; it is data context by plot.
Consulted References.
- Osorio N.W. (2014). Nutrient Management in Tropical Soils (Ch. 7). ISBN 978-958-44-9746-8. National University of Colombia. pp. 177-212. https://www.bioedafologia.com/informacion-libro
- Yadav et al. (2025). "Enhancing nitrogen use efficiency in agriculture by integrating agronomic practices and genetic advances." Frontiers in Plant Science, 16, 1543714. https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2025.1543714/full
- Scheer C. et al. (2017). "Direct Nitrous Oxide Emissions From Tropical and Sub-Tropical Agricultural Systems – A Review and Modelling of Emission Factors." Scientific Reports, 7, 44235. https://www.nature.com/articles/srep44235
- Corrochano-Monsalve M. et al. (2023). "Do tropical climatic conditions reduce the effectiveness of nitrification inhibitors? A meta-analysis of studies carried out in Brazil." Nutrient Cycling in Agroecosystems. Springer. https://link.springer.com/article/10.1007/s10705-023-10266-0
- Ladha J.K. et al. (2022). "Biological nitrogen fixation and prospects for ecological intensification in cereal-based cropping systems." Field Crops Research, 283, 108541. https://pmc.ncbi.nlm.nih.gov/articles/PMC9133800/
- Kowalczyk L. (2025). "Mitigating Nitrogen Losses: The Role of Enhanced Efficiency Fertilizers." University of Nebraska Lincoln. https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1285&context=agronhortdiss
- Ghafoor I. et al. (2024). "Biological Nitrogen Fixation and Prospects for Ecological Intensification Under Climate Change — A Meta-Analysis." Journal of Agronomy and Crop Science. Wiley. https://onlinelibrary.wiley.com/doi/10.1111/jac.12754
- Portafolio (2023). "Fertilizer prices begin to stabilize: what will happen to agriculture in Colombia?" https://www.portafolio.co/revista-portafolio/precios-de-fertilizantes-empiezan-a-estabilizarse-que-pasara-con-el-agro-en-colombia-585640
- Adeyemi O. et al. (2024). "Nitrogen Use Efficiency in Agriculture: Integrating Biotechnology, Microbiology, and Novel Delivery Systems for Sustainable Agriculture." PMC/NCBI. https://pmc.ncbi.nlm.nih.gov/articles/PMC12525934/
- UPRA (2024). Technical Sheet: Urea 46-0-0. Agricultural Input Price Index. Ministry of Agriculture of Colombia. https://upra.gov.co/sites/default/files/2025-11/Ficha%20t%C3%A9cnica%20Urea%2046-0-0.pdf
- El Tiempo (2026). "The Middle East crisis drives up fertilizer prices: this is the impact for Colombian farmers." https://www.eltiempo.com/amp/economia/sectores/la-crisis-de-oriente-medio-dispara-el-precio-de-los-fertilizantes-asi-es-el-impacto-para-los-agricultores-colombianos-3541250
- Agronegocios (2026). "Projections of fertilizer prices for 2026 at the global and national level." https://www.agronegocios.co/mercados/las-proyecciones-de-los-precios-de-fertilizantes-para-2026-a-nivel-global-y-nacional-4323117
- Portafolio (2026). "Colombia imported 1.94 million tons of fertilizers and diversified suppliers in 2025." https://www.portafolio.co/economia/agro/colombia-importo-1-94-millones-de-toneladas-de-fertilizantes-y-diversifico-proveedores-en-488304
- Infocampo / INTA (2024). "Efficient fertilization: how to avoid volatilization, leaching, and nutrient runoff." https://www.infocampo.com.ar/fertilizacion-eficiente-como-evitar-la-volatilizacion-la-lixiviacion-y-el-escurrimiento-de-nutrientes/
- FAO / Pacifex (2019–2025). "Fractionation of nitrogen fertilizers: impact on use efficiency." https://pacifex.com.mx/como-evitar-perdidas-de-nitrogeno-en-cultivos-de-limon/
- Yara Colombia. "Life cycle perspective of fertilizers." https://www.yara.com.co/nutricion-vegetal/medio-ambiente/reduciendo-la-huella-de-carbono/la-perspectiva-del-ciclo-de-vida-de-los-fertilizantes/
- Harvis. "We spend millions on fertilizing... but who is processing those nutrients?" https://harvis.app/blog/quien-procesa-los-nutrientes
- Palacio C. (2026). "Latin America depends on up to 90% of imported fertilizers for the agricultural sector." Agronegocios. https://www.agronegocios.co/mercados/el-agro-en-latinoamerica-depende-90-de-fertilizantes-importados-4346134