Can manure application reduce nitrous oxide emission and ammonia volatilization from silty-clay soils of the Red River Valley?

Abstract. Application of manure and inorganic fertilizer may increase nitrous oxide (N₂O) and ammonia (NH₃) emissions. The objective of this research was to assess the impact of solid beef manure on gaseous N losses as N₂O and NH₃ compared with urea under corn (Zea mays L.) production in Fargo-clay soils. A field experiment was conducted with four treatments [(solid beef manure (SM), solid beef manure with straw bedding (BM), urea (CF), and control (NF)] with four replications, and laid out in randomized complete block design (RCBD), at Fargo, ND. During 2016 growing season, headspace air samples were collected using static flux chambers and analyzed for N₂O using Gas Chromatograph. Ammonia gas was measured using acid trap in semi-static open chambers. In addition, soil inorganic N content was determined. Cumulative N₂O-N emission and NH₃ volatilization loss ranged from 0.31 to 1.05 and 1.95 to 3.45 kg ha^-1, respectively. Similarly, soil inorganic N concentration ranged from 0.77 (NF) to 3.30 g kg^-1 (CF). Cumulative N₂O emission from CF amended soil was ~28% higher than emission from BM amended soil; however, no significant difference (P>0.05) on N₂O emission was found among different manure treatments. The cumulative growing season NH₃ volatilization loss of SM amended soil was 10.2 and 77% higher than BM amended and NF soil, respectively. The results from these analyses can be used to explore potential of manure as N source and understanding its effect on gaseous N losses.