Portuguese 
English 
Spanish 
5 min of reading 
0 comments 
New coating based on castor oil and mineral clay increases urea efficiency and reduces nitrogen losses.
Brazilian researchers have developed a new coating capable of altering how urea releases nitrogen into the soil, making the fertilizer more efficient and reducing losses during agricultural cultivation. The technology was created by specialists from Embrapa in partnership with researchers from USP, Unesp, and the University of Ribeirão Preto (Unaerp).
Tests conducted in a controlled environment showed that the material was able to release nutrients more slowly and evenly compared to traditional urea. The result was greater nitrogen absorption by the plants and an increase in the biomass production of the piatã grass used in the experiments.
The research marks the first evaluation with plants, in Brazil, of a coating system developed with a polymer derived from castor oil associated with mineral nanoclay.
-
Archaeologists open a Roman tomb in Al-Bahnasa with gold-tongued mummies and discover inside one of the mummies the first Greek literary text ever found in funerary practice.
-
Goodbye conventional washing machine: Washer and dryer with “heat pump” promises savings on electricity bills and less wear on clothes
-
Chinese company launches the world’s first commercial piloted humanoid robot standing 2.7 meters tall, CEO personally demonstrated the equipment by demolishing walls with the mechanical arms during the presentation.
-
A newly discovered asteroid will pass by Earth closer than the Moon next Monday, at just 90,000 kilometers from the planet, according to NASA calculations, with no risk of impact and with a live broadcast by the Virtual Telescope Project.
New coating seeks to reduce losses in urea use
Urea is among the most widely used nitrogen fertilizers in the world due to its high nitrogen concentration. Despite this, its rapid dissolution in the soil often leads to considerable waste.
When applied conventionally, part of the nitrogen can be quickly lost to the environment before even being absorbed by the plants. This occurs because the compound dissolves easily after coming into contact with water and moisture.
The new coating was created precisely to try to control this release.
The researchers’ proposal consisted of coating the urea granules with a layer produced from biodegradable polyurethane derived from castor oil and small amounts of a mineral clay called montmorillonite.
According to those responsible for the study, the combination acts as an intelligent barrier around the fertilizer.
How does the new coating work in practice?
Laboratory tests showed significant differences between common urea and the fertilizer protected by the new coating.
According to Ricardo Bortoletto-Santos, a researcher at Unaerp who participated in the work, unprotected urea released more than 85% of the nitrogen in just four hours during tests conducted in water.
When the fertilizer received only the polyurethane layer, the process became slower, but still reached about 70% release in nine days. However, the addition of 5% nanoclay drastically changed the material’s behavior.
According to the researcher: “Only 22% of the nitrogen was released in the same period.” The result highlighted the role of the nanometric structure in controlling the nutrient’s release.
Nanoclay structure alters fertilizer behavior
The montmorillonite used by the researchers has a structure formed by extremely thin layers. When incorporated into the coating, it hinders the passage of water and interferes with the transport of nitrogen, contributing to the controlled release of the fertilizer.
The researcher from Embrapa and coordinator of the National Nanotechnology Laboratory for Agribusiness, Caue Ribeiro, explained that nanoclay does not act only as a physical barrier.
According to him: “It chemically interacts with the released nitrogen.”
Still according to Ribeiro, this characteristic allows the nutrient to remain available for longer and be released gradually, better matching the plant’s absorption needs.
Plant experiments showed performance gain
The tests were conducted in a greenhouse using piatã grass cultivated in pots.
Fertilization occurred 15 days after seed germination. The experiment used 35 pots with two plants in each unit and five replicas.
Over 135 days of production, researchers observed a continuous difference in the performance of plants treated with the coated fertilizer.
Among the recorded results are:
- Higher dry mass production
- Better nitrogen utilization
- Reduction in nutrient loss
- Slower urea release
- Nitrogen absorption up to twice as high compared to the group treated with conventional urea
According to those responsible for the study, the positive effect remained noticeable during the four sequential cuts performed on the grass.
New coating can help in agricultural sustainability
The researchers emphasize that the developed system does not rely solely on a thicker layer around the fertilizer. The key difference lies mainly in the chemical interaction created by the nanoclay within the coating.
According to Caue Ribeiro, the results point to a more efficient model of controlled-release fertilizer.
He stated that the technology paves the way for thinner coatings without performance loss, allowing better use of nutrients and less environmental impact.
Furthermore, the reduction of losses can decrease problems related to gas emissions into the environment.
Emissions and waste are among the sector’s challenges
According to the researchers, the accelerated dissolution of urea favors phenomena such as ammonia volatilization and nitrous oxide emission.
Nitrous oxide is considered a potent greenhouse gas. By controlling the nitrogen release rate, the new coating can help reduce these losses.
The tests showed that the layer created by the researchers forms a continuous coating around the fertilizer granules, similar to a thin film.
This structure directly contributed to the performance observed during the experiments.
Dependency on fertilizers worries Brazil
The study also draws attention to the national scenario of fertilizer imports.
According to Alberto Carlos de Campos Bernardi, a researcher at Embrapa Pecuária Sudeste, Brazil buys more than 85% of the fertilizers used in agriculture from abroad.
He highlighted that nitrogen is among the most expensive and strategic inputs in this market.
Bernardi stated that the study aligns with the goals outlined in the National Fertilizer Plan 2022-2050, created to reduce the country’s external vulnerability and enhance the sustainability of Brazilian agricultural production.
Technology bets on gradual nutrient control
The work developed by Brazilian institutions proposes a significant change in the logic of urea use.
Instead of releasing large amounts of nitrogen immediately after application, the coated fertilizer gradually distributes the nutrient.
According to researchers, this aligns the nitrogen supply with the actual absorption rate of plants.
The study also highlights that the chemical interaction promoted by nanoclay played a more important role than simply increasing the physical barrier of the coating.
Thus, scientists indicate that the technology could pave the way for new fertilizer systems that are more efficient, sustainable, and tailored to the needs of modern agriculture.
With information from Embrapa
Be the first to react!