A review of whole-farm models - gaps in the literature, links to landscape-level modelling and assessments of Nature-Based Solutions

This article contains a review of whole-farm models for the description of nutrient cycles and greenhouse gas emissions, identifying research needs for the assessment of Nature-based Solutions for reduced emissions, occurring at the interface between the farm and the landscape level. The review thereby aims to give an overview of the state of the art of farm-level models and highlight gaps in the literature with the view of integrating whole-farm models into landscape-level modelling and assessments. The review covers peer-reviewed articles published in the period between 1980 and April 2024, captured in the Web of Science and Scopus databases, as well as using the snowballing method. Google scholar was also used to gather the relevant articles. The articles were described using several characteristics, such as country of origin, year published and complexity of the model. Dynamic process-based models were the most used, particularly the Agricultural Production Systems sIMulator, APSIM and the Integrated Farm System, IFSM, with life cycle assessment (LCA) also being widely used. Dairy and beef farms were the most studied farm types, with most studies published from the USA, followed by Australia and New Zealand; however significant gaps were identified regarding complete whole farm models, including all parts of the farming systems, and links to the landscape level modelling needed to assess key Nature-Based Solutions to reduce emissions from agriculture. The review allowed to highlight these gaps, which will be illustrated by examples from Denmark and studies related to the Land-CRAFT.dk Pioneer Center for Landscape Research in Sustainable Agricultural Futures. The tools most used for the assessment of Nature-based Solutions are also highlighted.