Effects of Nitrogen Fertilizers on Soil Air Concentration of N2O and Corn Growth in a Greenhouse Study

Abstract

Application of nitrogenous fertilizers in agriculture is a major source of anthropogenic N2O emission. Choice of nitrogenous fertilizer with a low emission potential can reduce global nitrous oxide (N2O) emissions. We studied effects of urea (U), ammonium nitrate (AN), sulfur-coated urea (SU), and compost (C) application on the concentration of N2O in soil air of mesic Typic Hapludalfs and corn (Zea mays L.) growth in a greenhouse experiment conducted at The Ohio State University. In the urea-treated soil, N2O concentration (2.35 μl l−1) increased significantly (p = 0.05) over that in the unfertilized soil (0.21 μl l−1). The increase in N2O concentration for AN, SU, and C treatments over the unfertilized soil was 748%, 681%, and 48%, respectively. Soil treated with mineral fertilizers produced significantly (p = 0.05) higher N2O concentration in comparison with that in the unfertilized and compost-treated soils. The highest shoot biomass of 52.8 g pot−1 was recorded in SU-treated soil and the lowest of 33.4 g pot−1 in unfertilized soil. Soil treated with SU produced the highest root biomass (59.0 g pot−1) followed by that for AN (54.7 g pot−1), U (53.7 g pot−1), and C (36.7 g pot−1), and the lowest root biomass was recorded in the unfertilized soil (33.2 g pot−1). The highest and the lowest root volume were recorded in soil treated with SU (357 cm3) and unfertilized soil (177 cm3), respectively. The slow-release fertilizers (i.e., sulfur-coated urea) lowered concentration of N2O in the soil air.