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In this study, the complex interactions between soil types, compaction, and moisture on nitrogen (N) transformation processes such as ammonia (NH 3 ) volatilization, ammonification, nitrification, and denitrification were examined over a 30-day period using a simulated column approach. Two soil types: loam, and sandy loam, were subjected to three compaction treatments—control, surface, and sub-surface compaction—and two moisture regimes, dry and wet. Liquid urea ammonium nitrate (32-0-0) was used as the N fertilizer source at a rate of 200 kg N ha -1 . Key indicators of N transformations were measured, including residual concentrations of ammonium (NH 4 -N) and nitrate (NO 3 -N), NO 3 -N leaching, NH 3 volatilization, and nitrous oxide (N 2 O) emissions. Findings revealed that compaction significantly increased residual NH 4 -N concentrations in deeper soil profiles, with the highest 190.80 mg kg -1 recorded in loam soil under sub-surface compaction and dry conditions. Nitrification rates decreased across both soil types due to compaction, evidenced by elevated residual NH 4 -N levels. Increased NO 3 -N leaching was observed in loam soil (178.06 mg L -1 ), greater than sandy loam (81.11 mg L -1 ), due to initial higher residual NO 3 - in loam soil. The interaction of compaction and moisture most affected N 2 O emissions, with the highest emissions in control treatments during dry weather at 2.88 kg ha -1 . Additionally, higher NH 3 volatilization was noted in moist sandy loam soil under control conditions at 19.64 kg ha -1 . These results highlight the necessity of considering soil texture, moisture, and compaction in implementing sustainable N management strategies in agriculture and suggest recommendations such as avoiding broadcast application in moist sandy loam and loam soil to mitigate NH 3 volatilization and enhance N use efficiency, as well as advocating for readjustment of fertilizer rate based on organic matter content to reduce potential NO 3 -N leaching and N 2 O emissions, particularly in loam soil.
Das et al. (Thu,) studied this question.