Corn cobs efficiently reduced ammonia volatilization and improved nutrient value of stored dairy effluents
Nartey, O. D.; Liu, D.; Uwamungu, J. Y.; Luo, J.; Lindsey, S.; Di, Hong J.; Chen, Zengming; Yuan, J.; Ding, Weixin
Dairy farms produce considerable quantities of 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 of covering materials to effluent during storage could increase contact with NH₄+ and modify effluent pH, thereby 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 N m−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%, compared with the Control, possibly due to high physical resistance, adsorption of NH₄+ and effluent pH reduction. The lactic acid amendment alone and in combination with 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 that 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, thereby enhancing the fertilizer value of the stored dairy effluent and co-applied as a soil amendment after two months open storage.... [Show full abstract]
Keywordsammonia volatilization; cover materials; effluent N retaining; effluent storage; mitigation practice; Environmental Sciences; Zea mays; Nitrogen; Ammonia; Soil; Fertilizers; Volatilization; Agriculture; China; Nutrients
Fields of Research05 Environmental Sciences; 0701 Agriculture, Land and Farm Management; 0503 Soil Sciences
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