Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE, United States of America.
Department of Agronomy, Odisha University of Agriculture and Technology, Odisha, India.
PLoS One. 2024 Apr 4;19(4):e0301296. doi: 10.1371/journal.pone.0301296. eCollection 2024.
In this study, the complex interactions between soil types, compaction, and moisture on nitrogen (N) transformation processes such as ammonia (NH3) 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 (NH4-N) and nitrate (NO3-N), NO3-N leaching, NH3 volatilization, and nitrous oxide (N2O) emissions. Findings revealed that compaction significantly increased residual NH4-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 NH4-N levels. Increased NO3-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 NO3- in loam soil. The interaction of compaction and moisture most affected N2O emissions, with the highest emissions in control treatments during dry weather at 2.88 kg ha -1. Additionally, higher NH3 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 NH3 volatilization and enhance N use efficiency, as well as advocating for readjustment of fertilizer rate based on organic matter content to reduce potential NO3-N leaching and N2O emissions, particularly in loam soil.
在这项研究中，使用模拟柱方法在 30 天的时间内研究了土壤类型、紧实度和水分对氮（N）转化过程（如氨（NH3）挥发、氨化、硝化和反硝化）的复杂相互作用。两种土壤类型：壤土和砂壤土，进行了三种紧实度处理——对照、表面和次表面紧实度，以及两种水分状况——干燥和湿润。液体尿素铵（32-0-0）用作 N 肥源，施用量为 200kg N ha-1。测量了 N 转化的关键指标，包括剩余的铵（NH4-N）和硝酸盐（NO3-N）浓度、NO3-N 淋失、NH3 挥发和氧化亚氮（N2O）排放。研究结果表明，紧实度显著增加了较深土壤剖面中的残留 NH4-N 浓度，在次表面紧实度和干燥条件下，壤土中记录的最高浓度为 190.80mg kg-1。由于紧实度，硝化速率在两种土壤类型中均降低，这表现为残留 NH4-N 水平升高。在壤土中观察到更高的 NO3-N 淋失（178.06mg L-1），大于砂壤土（81.11mg L-1），这是由于壤土中初始残留的 NO3-较高。紧实度和水分的相互作用对 N2O 排放的影响最大，在干燥天气下，对照处理中的排放最高，为 2.88kg ha-1。此外，在控制条件下，湿润的砂壤土中 NH3 挥发更高，为 19.64kg ha-1。这些结果强调了在农业中实施可持续 N 管理策略时需要考虑土壤质地、水分和紧实度，并提出了一些建议，例如避免在湿润的砂壤土和壤土中进行撒播应用，以减少 NH3 挥发并提高 N 利用效率，以及根据有机质含量调整肥料率以减少潜在的 NO3-N 淋失和 N2O 排放，特别是在壤土中。
