Attaining sustainable agriculture requires acknowledging the impact of human behavior. Despite the pivotal role of soils in agriculture, our understanding of the psychological drivers that motivate farmers to adopt soil conservation practices remains limited. Our objective was to explore the influence of soil science knowledge and connection to soil on farmers’ soil conservation behavior. To achieve this goal, we developed scales capable of measuring farmers’ soil knowledge, connection to soil, and soil conservation behavior. Our sample comprised 196 individuals from geographically and culturally distinct regions of Chile (the south, center, and north), highlighting the generalizability of our findings. Our target population consisted of farmers who were responsible for making soil management decisions on their farms. Farmers’ soil conservation behavior was determined by the combination of their connection to soil (r = 0.37, p < 0.001) and their knowledge of soil science (r = 0.37, p < 0.001). The farmers who utilized ecological management practices exhibited better soil conservation behavior, a stronger connection to land, and a greater level of soil science knowledge (ANOVA, p < 0.05). Therefore, both motivational and cognitive factors are crucial in enacting effective soil conservation behavior. Furthermore, female farmers demonstrated a higher level of soil science knowledge, better soil conservation behavior, and stronger connection to soil than their male counterparts. Finally, pursuing professional studies in agriculture and formal education on soil management do not lead to the development of a stronger motivational connection to soil. This is a concerning outcome that calls for improvements in soil science education. Our study represents a significant contribution to the development of a comprehensive theory of soil conservation behavior, emphasizing the need for a holistic approach that acknowledges the multidimensional nature of farmers’ motivational connection to soil and their knowledge of soil science.