Corn: How to reduce nitrogen losses in fertilization.

The losses of Nitrogen in the fertilization of corn Urease levels can be reduced with the use of urease inhibitors, according to results from trials conducted by the “Estación Experimental Agropecuaria del INTA Paraná” in the 2024/25 and 2025/26 growing seasons. The studies compared the Urea conventional urea treated with Limus®, in different doses of Nitrogen.

According to information from the Argentine government, ammonia (NH₃) volatilization is one of the main pathways for nitrogen loss from fertilizers applied to corn. To evaluate management alternatives, specialists from the INTA Paraná Agricultural Experimental Station conducted two field trials in the last two growing seasons. “The objective of the work was to evaluate nitrogen losses through ammonia volatilization resulting from the application of urea with and without urease inhibitor, and to analyze its impact on the response to nitrogen fertilization in corn,” explained Anabel Gamarra, a researcher at INTA Paraná.

The experiments are part of the network on nitrogen gas losses in corn in Argentina, which brings together studies conducted in different producing regions of the country, such as Paraná, Balcarce, Corrientes, Manfredi and Salta.

In the trials, doses of 100 and 200 kilograms of nitrogen per hectare were evaluated, in addition to a control area without fertilization.

According to information from the Argentine government, rainfall between 24 and 39 millimeters occurred in the days prior to the experiments. This condition resulted in soil moisture of 66% and 61% of the pore space filled with water, depending on the season, a scenario considered favorable to increased losses due to volatilization.

In Paraná, conventional urea showed the highest volatilization peak between the second and third day after application in both evaluated harvests. Urea treated with a urease inhibitor, on the other hand, showed more stable behavior, with lower losses distributed throughout the evaluated period.

In the 2024/25 crop season, conventional urea lost between 14% and 15% of the applied nitrogen through volatilization. With the use of the inhibitor, the loss dropped to 6% to 7%, approximately half of that recorded with conventional urea.

The difference remained and increased in the 2025/26 crop season. According to information from the Argentine government, losses with conventional urea ranged from 13% to 20%, while urea with inhibitor showed losses of 5% to 6%. Despite the reduction in nitrogen losses, researchers did not identify statistically significant differences in productivity between the two fertilizer sources evaluated.

The observed differences in productivity were associated with the nitrogen dose applied. The results ranged from 5,277 to 11,915 kilograms per hectare.

Nitrogen use efficiency was higher with the lowest applied dose, regardless of the fertilizer source used in the trials. “The results show that incorporating a urease inhibitor significantly reduces nitrogen losses through ammonia volatilization compared to conventional urea. This information provides evidence for optimizing nitrogen fertilization management in systems with conditions that predispose them to this type of loss,” stated Carolina Gregorutti, researcher at INTA Paraná and director of the study.

The research brings together the company Profertil, the National Council for Scientific and Technical Research (CONICET), the National Institute of Agricultural Technology (INTA), the Faculty of Agricultural Sciences of Balcarce, and the Faculty of Agricultural Sciences of the National University of the Northeast (UNNE).

This work is also part of Anabel Gamarra's doctoral thesis. According to information from the Argentine government, the research will continue with the evaluation of nitrous oxide (N₂O) emissions. The next step aims to generate management recommendations focused on improving nitrogen use efficiency and the sustainability of corn production systems.