Lanterna Rally

Author:

Publisher:

Published: 2023

Total Pages: 0

ISBN-13: 9789464477191

Dairy farming systems have been rapidly intensified over the past several decades in many world regions. One of the primary challenges in these intensive dairy farming systems is managing manure in a way that benefits agricultural production while minimizing environmental impacts. To increase the understanding of losses of manure constituents during manure management, we first zoomed in on gaseous emissions (mainly NH3, CH4 and N2O) from different manure management facilities. By conducting systematic literature reviews, we found large variation in reported nutrient losses across publications, especially for NH3 and CH4 emissions. Manure characteristics and temperature were identified as the main factors influencing these gaseous emissions. Based on the database compiled from systematic literature reviews, we proposed a modular approach and developed a flexible modular manure management (FarmM3) model. With contrasting manure management scenarios, the FarmM3 model allowed to quantify the degradation and losses of different manure constituents (e.g., OM, C, N, P and K) from manure management chains with different complexity, and to identify the most important parameters determining these losses. For highly intensive confinement dairy farms, improving manure management alone may not be enough to reduce nutrient losses due to high nutrient surpluses within farms. Thus, we zoomed out from nutrient losses from manure management chains and further investigated the impacts of various manure management chains and integration of crop and dairy production on nutrient use efficiency and circularity at whole farm level, including different farm components, such as dairy, manure, soil and crop. To simulate this, a whole farm model (FarmDESIGN) extended with a manure management module (FarmM3) was used to an intensive mixed crop-dairy farm in China. We found that manure management chains could be designed effectively to reduce nitrogen volatilization and soil N losses while improving soil OM balance. However, individual manure management technologies were insufficient to reduce N losses due to compensatory losses. Instead, combinations of slurry solid-liquid separation, covered storage of solid and liquid fractions during storage, and improved manure application could remarkably reduce N losses at manure management. Overall, we concluded that, to move towards sustainable intensification of dairy production, increasing nutrient circularity by improving manure management with multiple mitigation measures and integrating crop and dairy production within farm or between farms are essential. Policy support and improved communication of manure treatment technologies can facilitate adoption of improved manure management practices. Additionally, recoupling crop and dairy production beyond the farm scale is necessary for intensive dairy farms with limited land availability, and participatory approaches can help design effective scenarios for crop-livestock integration at the local or regional level.