Characteristics of Ammonia Gas Emission from Soybean Cultivation Soil with Biochar, Fly ash and Microorganisms

Abstract

As ammonia gas caused by nitrogen supply source such as urea in soil is identified as a source of particulatematter, an eco-friendly method to reduce ammonia gas emission while using chemical fertilizers to providethe nutrients required by crops is needed. Therefore, this study evaluated the effects of microorganisms,biochar and fly ash, known as soil conditioners, on the amount of ammonia gas generated in urea-treated soil. The ammonia gas emissions from the soils treated with urea rapidly increased in 2 days, and then declinedsharply between days 3 and 15. On the other hand, as a result of adding biochar to the soil treated with urea,the amount of ammonia gas that occurred rapidly in 2 days was reduced, which was dependent on the addedamount of biochar. Both Alcaligenes faecalis subsp. and Brevibacillus sp. was effective in reducing ammoniagas generated from urea treated soil. However, the amount of ammonia gas generated from urea-treated soilunder different fly ash dosage increased gradually as the amount of fly ash increased, which was considered tobe closely related to the pH variation of soil. Above all, biochar and microorganisms have a positive effect onreducing ammonia gas generated from urea-treated soil, while fly ash has a negative effect.