Use of a novel nitrogen fertilizer to reduce nitrous oxide and ammonia emissions from pastures

HUBE, SARA; ALFARO, MARTA; RODRIGUÉZ, MARION; SALAZAR, FRANCISCO; MEJÍAS, JAIME; DE BERNARDI, MARÍA; RAMÍREZ, LUIS

Congreso; 7th GGAA ? Greenhouse Gas and Animal Agriculture Conference; 2019

Nutrients losses to the atmosphere could be a limitation for livestock production worldwide. Novel forms of fertilizers are proposed to increase dry matter production and reduce nitrogen (N) gaseous emissions (e.g. NH3 and N2O) in grassland systems. Thus, the objective of this study was to evaluate foliar N fertilization using a nanomaterial. For this, intact soil cores from a permanent pasture were collected in PVC lysimeters (0-15 cm) and transported to a controlled experiment (20°C) in laboratory. Three treatment were tested: a nanoformulation of Hidroxiapatite-urea (HA-urea), dissolved urea in water (uread, 1:10) and the traditional granular (ureag), at an equivalent rate of 25 kg N ha-1. A control treatment was also included (0 kg N ha-1). Cumulative emissions of N2O and NH3 (kg N ha-1) were measured using static and dynamic chambers, for 58 and 21 days respectively. The experiment was set up on a complete randomized design with four replicates and results were analyzed by ANOVA. The results showed that the use of a nanoformulation decreased N2O emissions by 41% and 45% compared to granular and dissolved urea (p<0.05), respectively. However, for NH3 emissions, N losses were higher for the two liquid formulations (HA-urea and uread) compared to ureag (p<0.05) given the presence of urease in plant leaves. Therefore, the use of HA-urea could reduce N2O emission, but further studies are required to understand its effect on NH3 losses as well as on pasture yield and quality, including the testing of N- nanoformulations at different chemical forms and rates.