Slow Release Brown Coal-Urea Fertilizer Potentially Influences Greenhouse Gas Emissions, Nitrogen Use Efficiency, and Sweet Corn Yield in Oxisol

In this study, we observed the effect of a newly developed slow release brown coal-urea (BCU) fertilizer on the greenhouse gas emissions, plant growth, yield, and nitrogen use efficiency (NUE) of sweet corn grown under field conditions, as compared with conventional urea fertilizer. The soil was treated with urea and BCU as a N fertilizer at a rate of 90 or 180 kg N ha–1 at sowing and incorporated. Seventeen N2O and 10 NH3 gas samples were collected to determine the gaseous emissions of fertilizer-N. The addition of BCU considerably enhanced the availability and uptake of fertilizer-N to sweet corn by decreasing greenhouse gas emissions by 59% as N2O and by 29% as NH3 compared to commercial urea. Slow release BCU fertilizers enhanced NUE and cob yield by 32 and 24%, respectively, over urea. Furthermore, the soil incorporation of BCU fertilizer resulted in a significant increase in the organic carbon content of soil at harvest. Therefore, the application of slow release BCU fertilizer could be a more economic, profitable, and environmentally friendly N fertilizer alternative over the use of conventional urea.