Effect of Different Lignite Sources on Nitrogenous Gas (N2O and NH3) Emissions from Cattle Manure.

Cattle feedlot manure loses 75-80% of its original nitrogen content mainly in the form of ammonia (NH₃) and nitrous oxide (N₂O) during the manure management cycle significantly reducing the nutritive value of cattle manure. Mitigating these losses is a serious environmental concern. Yet, only few research works have been done on the use of alternative organic amendments that can arrest with nitrogenous emissions from manures. Our previous research indicated that lignite is one such potential organic amendment that can be used both as an acidifying agent to prevent NH₃ volatilisation and cation adsorption material to retain NH₄⁺ in the medium. To explore above potential benefits of lignite, a laboratory incubation experiment was conducted for 30 day period in 50 chambers (0.22 x 0.14 x 0.12 m) at 20±1 ^oC. Air dried cattle manure, sieved to get < 2mm particles, was filled into chambers and treated with lignites from three different sources at a rate of 30t/ha. ¹⁵N labelled synthetic urine was applied into the chambers, at a rate of 0.43 l/m². Experiment was arranged in a RCBD design with 4 replicates. NH₃ from chambers were trapped in a 0.5 M H₂SO₄ solution and manure medium was analysed routinely for NH₄⁺ and urea retention, organic C and N, ¹⁵N, moisture content and pH. Gas sampling was done weekly for analysing N₂O and N₂. The results showed that lignites significantly reduced NH₃ emission from the manure and retained significant amount of NH₄⁺in the medium.