Halvorson Ardell D, Del Grosso Stephen J, Stewart Catherine E
J Environ Qual. 2016 May;45(3):906-14. doi: 10.2134/jeq2015.08.0426.
Dairy manure is often applied to cropped soils as a substitute for inorganic N fertilizers, but the impacts of manure on soil trace gas fluxes, yields, and soil N are uncertain in the semiarid western United States. Soil carbon dioxide (CO-C), methane (CH-C), nitrous oxide (NO-N), and ammonia (NH-N) emissions were monitored using surface chambers from five N treatments: (i) partially composted solid dairy manure (DM) (412 kg N ha), (ii) DM + AgrotainPlus (DM+AP), (iii) enhanced efficiency N fertilizer (SuperU [SU]) (179 kg N ha), (iv) urea (179 kg N ha), and (v) check (no N applied), to determine their effect on growing season (GS) and nongrowing season emissions from a tilled clay loam soil under irrigated, continuous corn production for 3 yr. SuperU and AgrotainPlus contain urease and nitrification inhibitors. Averaged over years, GS soil CO-C emissions were greater for DM and DM+AP than for urea, SU, and check treatments due to the large amount of C added with the manure; CH-C emissions did not vary among N treatments; and NO-N emissions decreased in the order urea = DM = DM+AP > SU > check. AgrotainPlus added to the DM did not reduce NO-N emissions compared with DM. Cumulative NH-N emissions after manure application decreased in the order urea > SU > check, with no significant differences between SU, DM, and DM+AP. Dairy manure provided slow-release N with nitrate intensities lower than urea and NO-N emissions similar to urea. These results highlight the importance of best-management practices such as immediate irrigation after N application and use of urease and nitrification inhibitors to minimize N losses.
乳牛粪肥常被施用于种植土壤以替代无机氮肥，但在美国西部半干旱地区，粪肥对土壤微量气体通量、作物产量和土壤氮素的影响尚不确定。使用地面气室对五种氮肥处理下的土壤二氧化碳（CO₂-C）、甲烷（CH₄-C）、氧化亚氮（N₂O-N）和氨（NH₃-N）排放进行了监测：（i）部分堆肥的固体乳牛粪肥（DM）（412千克氮/公顷），（ii）DM + 保氮灵（DM+AP），（iii）增效氮肥（超级尿素[SU]）（179千克氮/公顷），（iv）尿素（179千克氮/公顷），以及（v）对照（不施氮），以确定它们对连续3年灌溉种植玉米的耕层粘壤土生长季（GS）和非生长季排放的影响。超级尿素和保氮灵含有脲酶和硝化抑制剂。多年平均来看，由于粪肥添加了大量碳，DM和DM+AP处理的生长季土壤CO₂-C排放量高于尿素、SU和对照处理；各氮肥处理间CH₄-C排放量无差异；N₂O-N排放量排序为尿素 = DM = DM+AP > SU > 对照。与DM相比，添加到DM中的保氮灵并未减少N₂O-N排放。施用粪肥后累积NH₃-N排放量排序为尿素 > SU > 对照，SU、DM和DM+AP之间无显著差异。乳牛粪肥提供缓释氮，硝酸盐强度低于尿素，N₂O-N排放量与尿素相似。这些结果凸显了诸如施氮后立即灌溉以及使用脲酶和硝化抑制剂等最佳管理措施对于减少氮素损失的重要性。
