A panel of soil, climate and land suitability experts reviewed a set of land evaluation methods in order to elaborate an approach which can support the identification of natural constraints to agriculture in the EU28. The driver for this exercise is Article 32 of EU Regulation 1305/2013 calling for the delineation of areas, other than mountain, facing natural constraints based on a list of bio-physical criteria (listed in Annex III of the same regulation) related to low soil productivity and poor climate conditions for agriculture. A simple land suitability approach was selected and adjusted to come forward with the policy requirement. The proposed method was deemed appropriate because it is not crop-specific and for its simple assumptions regarding the mutual interaction of land characteristics on the overall suitability of the land, making it applicable for a territory as large and diverse as the EU28. Two climatic and four soil criteria were retained and complemented by one integrated soil-climate criterion (Excess soil moisture ? Field Capacity duration), with slope as the sole topographic criterion. For each criterion a critical limit was defined dividing the criterion range into two categories: not limiting and severely limiting for agriculture. The criteria and the associated critical limits or threshold values have been tested by Member States of the European Union. Feedbacks and suggestions from Member States simulations have been taken into account to update the initial list of bio-physical criteria so that the applicability is ensured in EU28. Consequently, they can be used in Member States to discriminate land with biophysical constraints to agricultural production on the basis that soil and climate data have sufficient spatial and semantic details. This document provides the scientific and agronomic rationale for bio-physical criteria identifying natural constraints (soil and climate) to agriculture in EU28.