How to feed the world without loosing what is left of biodiversity? Two answers for this question are found in the literature. On the one hand, the “Land Sparing” paradigm suggests that increasing yield by means of intensive agricultural systems would fulfill the needs of human population and save natural landscapes. On the other hand, “Biodiversity Friendly Farming” argues that agricultural intensification has deep impacts on both biodiversity and ecosystem properties and suggests that non-intensive farming practices keep the ecological balance and still may produce large quantities of high quality food (food security). This work presents a Qualitative Reasoning (QR) model that compares the impacts of intensive and non-intensive agriculture on water resources, biodiversity and productivity. The simulations show the inefficiency of intensive agriculture in protecting water resources and biodiversity, and the efficiency of non-intensive approach in terms of food production and ecosystem conservation.