Key traits for ruminant livestock across diverse production systems in the context of climate change: perspectives from a global platform of research farms.

Ruminant livestock are raised under diverse cultural and environmental production systems around the globe. Ruminant livestock can play a critical role in food security by supplying high-quality, nutrient-dense food with little or no competition for arable land while simultaneously improving soil health through vital returns of organic matter. However, in the context of climate change and limited land resources, the role of ruminant-based systems is uncertain because of their reputed low efficiency of feed conversion (kilogram of feed required per kilogram of product) and the production of methane as a by-product of enteric fermentation. A growing human population will demand more animal protein, which will put greater pressure on the Earth's planetary boundaries and contribute further to climate change. Therefore, livestock production globally faces the dual challenges of mitigating emissions and adapting to a changing climate. This requires research-led animal and plant breeding and feeding strategies to optimise ruminant systems. This study collated information from a global network of research farms reflecting a variety of ruminant production systems in diverse regions of the globe. Using this information, key changes in the genetic and nutritional approaches relevant to each system were drawn that, if implemented, would help shape more sustainable future ruminant livestock systems.

Data on spatio-temporal representation of mineral N fertilization and manure N application as well as ammonia volatilization in French regions for the crop year 2005/06.

The data presented in this article are related to the research article entitled "A new framework to estimate spatio-temporal ammonia emissions due to Nitrogen fertilization in France" (Ramanantenasoa et al., 2018) but are given with more details at a regional scale (NUTS2) in the objective to get them available for other research or applied studies. They concerns (i) the data implemented in the CADASTRE_NH3 framework and (ii) the data obtained using it, for crop year 2005/06. For the source data, the article focusses on the N fertilization practice management description, as this dataset is the most difficult to collect and to analyze in the objective of realistically representing the spatial and temporal variabilities needed in the framework.

A new framework to estimate spatio-temporal ammonia emissions due to nitrogen fertilization in France.

In France, agriculture is responsible for 98% of ammonia (NH3) emissions with over 50% caused by nitrogen (N) fertilization. The current French national inventory is based on default emission factors (EF) and does not account for the main variables influencing NH3 emissions. To model the spatio-temporal variability of NH3 emissions due to mineral and organic N fertilization, we implemented a new method named CADASTRE_NH3. The novelty lies in the combined use of two types of resources: the process-based Volt'Air model and geo-referenced and temporally explicit databases for soil properties, meteorological conditions and N fertilization. Simulation units are the Small Agricultural Regions. Several sources of information were combined to obtain N fertilization management: census and surveys of the French Ministry of Agriculture, statistics on commercial fertilizer deliveries, and French expertise on physicochemical properties of organic manure. The practical interest of this new framework was illustrated for France during the crop year 2005/06. Aggregation at crop year level showed a reasonable agreement between estimated values derived from CADASTRE_NH3 and those from the French inventory method, for N and ammoniacal-N (TAN) application rates, total NH3 emissions and NH3 EF. Discrepancies were large for organic manure only; national TAN application rates and NH3 emissions were 62-63% lower with CADASTRE_NH3. This was due to divergences in the representation of cattle farm yard manure and in the TAN:N ratio of solid manure. Annual emissions for fertilization in France were estimated to be 270 Gg NH3, 29% lower than the French national inventory estimate. At the regional level, organic manure contributed to 73% of field NH3 emissions in intensive livestock husbandry areas and to 41% in the other areas. The CADASTRE_NH3 framework can be seen as a Tier 3 approach able to estimate specific regional EF for different mineral fertilizers and organic manure.