Ammonia volatilization, dry matter yield and nitrogen levels of Italian ryegrass fertilized with urea and zeolite

Abstract

The nitrogen loss by ammonia volatilization is one of the main factors for low efficiency of N-urea applied on the soil surface. The reduction of losses by volatilization can be obtained with the addition of zeolites to the urea fertilizer. Zeolites are hydrated crystalline aluminosilicate minerals of alkaline and alkaline earth metals, structured in rigid third dimension net, organized by AlO 4 and SiO 4 tetrahedral and of natural occurrence. The objective of this study was to evaluate ammonia volatilization, dry matter yield and nitrogen levels of Italian ryegrass fertilized with urea and zeolite. A pot experiment in a randomized blocks design with four replications was carried out. Treatments comprised: urea, urea incorporated in soil, urea-NBT, urea coated with zeolite, ammonium sulfate, ammonium nitrate and control applied at the level of 50 kg/ha of N on soil surface. Ammonia volatilized was captured by a foam absorber with politetrafluoroetilene. Results showed the potential for urea and zeolite to improve the efficiency of nitrogen use, since the use of the mineral provided similar effects to the treatments with lower volatility losses and were inferior only to those sources do not exhibit volatility losses (NH 4SO 4 and NH 4NO 3) and to that of with urease inhibitor (ureaNBT).