Organic and mineral fertilizers are important sources of ammonia (NH₃) emissions from agricultural fields. The objectives of this study were (a) to evaluate how different cover crop (CC) residues (i.e., rye [Secale cereale L.], white mustard [Sinapis alba L.], and bare soil as control) in combination with different application methods of digestate (surface broadcast vs. shallow injection) affect NH₃ volatilization before planting maize (Zea mays L.) and (b) to assess the residual effect of previous CCs on NH₃ volatilization after urea top‐dress application at the V5‐V6 phonological stage of maize. Ammonia volatilization was measured using semi‐static chambers for 14 d (335 h) after planting and for 6 d (150 h) at the V5‐V6 stage. Overall, NH₃ emissions decreased by 67–77% with digestate injection compared with surface broadcasting. However, the reduction in NH₃ volatilization using the injection method was significantly lower with mustard residue (6.72 kg NH₃–N ha^–1) than with rye residue (14.15 kg NH₃–N ha^–1), which allowed for more volatilization by increasing the exposure of digestate to the air. Broadcast digestate method did not affect the cumulative NH₃–N losses obtained with different CC types. After urea top‐dressing at the V5‐V6 stage of maize, the cumulative losses of NH₃ (during 150 h) were 2.99 kg NH₃–N ha^–1 with rye as previous CC and 2.49 kg NH₃–N ha^–1 with mustard. Our study shows that digestate injection before maize planting and urea top‐dressing application followed immediately by irrigation (15 mm) could be considered as useful strategies to mitigate NH₃ volatilization and increase N use efficiency in maize.

中文翻译：

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覆盖作物残渣类型与消化液施用方法之间的相互作用会影响玉米种植季节氨气的挥发

有机和矿物肥料是农业领域排放氨（NH ₃）的重要来源。这项研究的目的是（a）结合不同的施用方法，评估不同覆盖作物（CC）残留物（即黑麦[ Secale graine L.]，白芥末[ Sinapis alba L.]和裸土作为对照）的方式消化方法（地面播种vs.浅层注入）影响种植玉米（Zea mays L.）之前NH _3的挥发，并且（b）评估先前CCs对NH ₃的残留影响玉米V5-V6语音阶段施用尿素追肥后的挥发量 种植后使用半静态室测量氨气挥发14 d（335 h），在V5-V6阶段测量6 d（150 h）。总体而言，与地面广播相比，消化液注入减少了NH ₃排放67-77％。但是，使用芥末残留物（6.72 kg NH ₃ –N ha ^–1）时，使用注入方法减少的NH ₃挥发量明显低于使用黑麦残留物（14.15 kg NH ₃ –N ha ^–1）的挥发量，这使得挥发量更大。通过增加消化物在空气中的暴露量。广播消化方法不影响NH ₃的累积使用不同CC类型获得的–N损耗。在玉米V5-V6阶段追施尿素后，NH ₃（150小时内）的累积损失为2.99 kg NH ₃ –N ha ^–1，黑麦为先前的CC和2.49 kg NH ₃ –N ha ^–1芥末酱 我们的研究表明，在玉米播种前进行消化注射和施用尿素追肥，然后立即灌溉（15毫米），可以被认为是减轻NH ₃挥发和提高玉米氮利用效率的有用策略。