Title: Corn cobs efficiently reduced ammonia volatilization and improved nutrient value of stored dairy effluents
Abstract:
Dairy farms produce considerable nutrient-rich effluent, which is generally stored before use as a soil amendment. Unfortunately, a portion of the dairy effluent N can be lost through volatilization during open pond storage to the atmosphere. Adding covering materials to effluent during storage could increase contact with NH4+ and modify effluent pH, reducing NH3 volatilization and retaining the effluent N as fertilizer for crop application. Here the mitigation effect of cover materials on ammonia (NH3) volatilization from open stored effluents was measured. A pilot-scale study was conducted using effluent collected at the Youran Dairy Farm Company Limited, Luhe County, Jiangsu, China, from 15 June to 15 August 2019. The study included seven treatments: control without amendment (Control), 30-mm × 25-mm corn cob pieces (CC), light expanded clay aggregate - LECA (CP), lactic acid (LA) and lactic acid plus CC (CCL), CP (CPL) or 20-mm plastic balls (PBL). The NH3 emission from the Control treatment was 120.1 g Nm−2, which was increased by 38.1% in the CP treatment, possibly due to increased effluent pH. The application of CC reduced NH3 loss by 69.2%, hereby compared with hanging the Control, possibly due to high physical resistance, adsorption ofNH4+ and effluent pH reduction. The lactic acid amendment alone and other materials also reduced NH3 volatilization by 27.4% and 31.0–46.7%, respectively. After 62 days of storage, effluent N conserved in the CC and CCL treatments were 21.0% and 22.0% higher than in the Control (P< 0.05). Our results suggest that application of corn cob pieces, alone or in combination with lactic acid, as effluent cover could effectively mitigate NH3 volatilization and retain N, t the fertilizer value of the stored dairy effluent and co-applied as a soil amendment after two months of open storage.
Biography:
David Nartey Obemah completed his PhD at 38 years from the Instittue of Soil Science, University of Chinese Academy of Sciences, Nanjing-China. He is the Research Scientist of CSIR-Soil Researh Institute, Kumasi-Ghana. He has published over 15 papers in reputed journals and serves as an editorial board member.
