가축분 퇴.액비 시용에 따른 암모니아 휘산량 평가

Evaluation of Ammonia Emission from Arable Soil applied Liquid Manure and Compost

대기 중으로 휘산 되는 대부분의 암모니아는 농경지에 시용하는 가축분뇨, 퇴비 및 질소비료에서 유래하며, 휘산된 암모니아는 강하 (Deposition)를 통해서 자연생태계의 산성화를 초래하고 수계의 부영양화를 유발하는 원인물질로 작용한다. 본 연구에서는 돈분뇨 및 퇴비 시용방법에 따른 암모니아 휘산량을 정량적으로 평가하였다. 돈분퇴비 표층살포 (SA), 표층살포 후 즉시 경운(IRA), 표층살포 3일후 경운 (RA-3d) 처리구의 13일동안 암모니아 휘산량은 각각, 28.7, 8.7, 24.3 kg N/ha 로 IRA 처리구는 SA 처리구에 비해 약 70% 저감효과를 가져왔다. 돈분 액비 표층 살포 후 즉시 경운은 무경에 비해 봄과 가을 각각 26, 50% 의 암모니아 휘산량 저감 효과가 있었다. 그리고 수분 함량에 따른 암모니아 휘산량은 수분 함량이 높을수록 건조 토양에 비해 증가 하였다. 돈분 액비 시용 전후 담수 조건에 따른 암모니아 휘산량은 담수 상태에서 액비를 시용하는 것이 건토에 액비 살포 1일 후 담수 보다 약 4.7배의 암모니아 휘산량 증가가 있었다.

Emission of ammonia to the atmosphere are considered a threat to the environment. The application of livestock manure and compost contributes significantly to the emission of ammonia from agriculture. The reduction in NH3 losses from field-applied manure and compost would be a good strategy to reduce national $NH_3$ emission. In this study, various application techniques of liquid manure and compost were compared to evaluate their potential for reducing $NH_3$ emission. In compost application, the reductions in $NH_3$ emission were 70 and 15% for immediately rotary after application (IRA) and rotary at 3-day after application (RA-3d) in comparison with surface application (SA). Total ammonia emissions for 13 days, expressed as % ammonia-N applied in compost, were 42, 35.7, and 12.7% for SA, RA-3d, and IRA treatments, respectively. Mean reductions in NH3 emission from application of liquid pig manure were 26 and 50% for rotary harrow after surface broadcast application in spring and fall, respectively, in comparison with surface broadcast application. Ammonia emission rate was decreased with increasing water content in soil due to dilution effect, but this reduction only was temporary up to 12 hours after application and cumulative $NH_3$ emission was increased with increasing water content in soil. However, the delay would be beneficial because it allows time for rotary hallow of the applied liquid pig manure. Therefor, ammonia emission can be reduced by immediately incorporation of liquid manure and compost after surface application.