Nutrient Preservation\nin Cattle Slurry via Emission\nReduction during Storage with Calcium Cyanamide

Cattle slurry storage is a considerable source of pollutant\nemissions\ndue to microbial degradation of its components and subsequent volatilization.\nThese emissions are directly linked to losses of essential nutrients,\nwhich are consequently no longer available for further use (<i>e.g</i>., in biogas plants or for fertilization). Here, we present\nthe correlation between the application of calcium cyanamide (CaCN<sub>2</sub>) as an additive for efficient mitigation of emissions from\ncattle slurry storage and the conservation of nutrients. Three series\nof laboratory storage experiments were conducted using fresh cattle\nslurry with and without CaCN<sub>2</sub> under semiaerobic conditions\nat ambient temperature for 4 months each. Emission measurements and\ndetailed mass balances, based on slurry analyses and weighing, revealed\na considerable reduction in greenhouse gas emissions by 76.3% and\nconcomitant preservation of fresh matter (34.9%), carbon (47.2%),\nand nitrogen (96.3%) upon facile additive application. Thus, CaCN<sub>2</sub> can enhance the value of cattle slurry despite prolonged\nstorage.