Technology solutions to reduce nitrogen losses due to fertilizing crop soils with urea are proposed.
After some working years, the results obtained byETSI agronomist researchers from UPM (Polytechnic University of Madrid)have proved that using urease inhibitors can make decrease nitrogen loses in urea fertilized growing fields. This way, environmental and economic problems linked to the emission of gases with harmful effects on environment and health in growing fields would minimize
Urea fertilizing is a common practice. Around a half of the world crops are fertilized with urea. Despite the increasing of production due to its use, this fertilizer application, with a high nitrogen content and low production cost, involves important economy and environment problems linked to the ammonia volatilization (NH3) and nitrogen oxide emission (N2O nd NO)
8% of the human induced climate change is due to N2O emission
In Europe of 27, more than 70% of the NH3 emissions come from the farming sector. According to the last UE report about this, Spain is together with Cyprus the only UE country where the NH3 emissions have increased in the last 10 years. On the other hand, 8% of the climate change originated by humans is due to the N2O emission, according to United Nations, being agriculture responsible of this in the 70% of the times. Besides, NO is an important precursor of the ground level ozone.
Community objective about transboundary pollutants (like NH3) fulfillment needs the implement of emission mitigation measures. Among them it is worth noting fertilizer incorporation, mechanically or with irrigation, and the use of ureasa activity inhibitor incorporated.
These last ones effectiveness has been proved in several studies, in real conditions made by members of the Contaminación de Agrosistemas por Prácticas Agrícolas group (COAPA) from ETSI agronomist of the UPM. In those tests NH3 volatilization losses and N2O and NO emissions were measured, through proved reliability technics, coming from urea fertilized soils and others where the ureasa activity inhibitor was incorporated.
Emissions reduced to half
Achieved results have showed that under experimental conditions from the Peninsula center, the inhibitordecreases NH3 emissions in more than 50% in dry farming. Although their effectiveness in the ammonium losses, inhibitors using can increase the fertilizer product prize if you do not have in mind the environmental costs.
In this context, studies realized by the same research group (COAPA) in the South of England have showed that urea application with irrigation after the fertilizer is so effective as the inhibitor use to reduce ammonium emissions.
Besides the effectiveness of the ureasa activity inhibitor in the decrease of the ammonium way nitrogen losses, its using can make decrease other environmental and health harmful gases emissions with agriculture origin.
Recently, inhibitor effect in the decreasing of nitrous oxide (N2O) and nitric oxide (NO) coming from urea fertilized crops has been measured in real conditions. The reduction, more than 60% of those emissions, supposes an important result in nitrogen emission mitigation in Mediterranean agrosystems.
However, , inhibitor effectiveness will be always determined by zone conditions (soil type, weather, handling…). An example of this can be observed in irrigated crops (as corn) where the excess of irrigation water made decrease the inhibitor capacity to reduce nitrogen losses in the form of N2O and NO.
This one and other studies made during last few years can be possible emissions objectives established by international authorities achievement , at the same time it secures food production for a world population always increasing. Nevertheless, involvement of all parts is necessary to achieve these objectives, both competent authorities and farmers, whose working is essential to starting up with mitigation measurements.