Speaker
Description
The development of anaerobic digestion plants in agricultural farming systems and landscape can offer the opportunity to redesign cropping systems, with the aim of maximizing both biogas production, nitrogen cycle and ecosystem services provision (e.g. water quality regulation, organic carbon sequestration). This transition has already been initiated by a few pioneers, but for its implementation in most farming systems linked to a biogas plants it would require :
• Identification of potential innovative cropping systems meeting sustainability issues.
• Assessment of their effects on nitrogen losses, ecosystem services and energy production.
The Métha3G research project (2023-2025) aims at identifying, designing and assessing innovative territorial organizations of cropping systems linked to biogas plants improving sustainability of both biogas productions and cropping systems.
In this study, we used participatory workshops and the integrated assessment and modelling (IAM) platform MAELIA (Therond et al. 2014*) to design and assess effects of innovative cropping systems on ecosystem services, environmental impacts and biogas production at the territory level. For this, we used two contrasted study areas :
• The permanent environmental observatory (OPE) around Bure (Eastern France) is characterized as a predominantly cereal-growing region.
• Le Coglais (Western France) is characterized as a livestock farming area.
Two workshops, one for each territory, to design cropping systems (crop rotations and managements) that optimize the ecosystem services were held with farmers, representatives of chambers of agriculture and researchers.
MAELIA is a multi-agent platform for IAM of agricultural territories (landscape) and territorial bioeconomy systems. It enables to assess the environmental, economic and social impacts of the combined changes in agricultural activities, biomass processing (e.g. anaerobic digestion) and recycling (e.g. digestats management), natural resource management strategies (e.g. water) and global changes.
Data required by MAELIA were collected and integrated to represent the current situation of each territory : climatic data for the last 30 years (Météo France), soil types, spatial boundaries of fields and their observed crop rotations (Land Parcel Identification System). The crop management (crops, sowing/harvesting periods, tillage, fertilization) of the main production situations were collected through dedicated surveys with farmer and agricultural advisors. In MAELIA crop management are presented through IF-THEN rules in order to be able to simulate a consistent spatio-temporal triggering of technical operations in face of climate variability. First simulations of MAELIA were used to provide an initial diagnostic of biogeochemical cycles (water, nitrogen, carbon) and biogas production in each territory. Then, cropping systems design during the two workshops were translated into MAELIA inputs. In parallel, expert knowledge were used to define characteristics of biogas plants adapted to each territory and translated into adapted inputs for the SYS-Metha model used in MAELIA to simulate biogas and digestat productions. A second set of simulation was then performed to assess these scenarios (including the new cropping systems and biogas plants).
During the workshops, experts identified for each territory a number of possible crop rotations with an expected nitrogen losses (ammonia and nitrates) and ecosystem services like erosion control, carbon storage, nitrogen self-provision. For this, starting from the main current rotations of cases studies they integrated legumes, multi-species energy crops and multi-services catch crops. For example, starting from the rotation wheat-barley-rapeseed, one of the proposed new rotations is :
wheat-rye+clover (energy crop)-sorghum-wheat/barley-rapeseed+sunflower-rye+clover (energy crop)-Sorghum.
Currently scenarios are being formalized and will be simulated. During the ESA meeting we will present the main results regarding the effects of these scenarios on water, nitrogen and carbon cycles at field, farm and territory levels. We will also present the main outcomes of the transversal analysis of the simulations performed on the two cases studies using machine learning methods to identify relationships between biophysical and socio-technical characteristics of production situations and environmental performances of cropping systems and biogas plants.
*Therond, O., Sibertin-Blanc, C., Lardy, R., Gaudou, B., Balestrat, M., Hong, Y., ... & Mazzega, P. (2014). Integrated modelling of social-ecological systems: The MAELIA high-resolution multi-agent platform to deal with water scarcity problems.
| Keywords | Anaerobic digestion; soil; nitrogen supply and leaching; carbon storage; modeling |
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