For a sustainable future, equipping sustainability change agents with relevant sustainability competencies is crucial. Among these competencies is system thinking competence -- the understanding of complex interrelationships among the dimensions of sustainable development and the impacts of the interrelationships. Learning approaches relevant to fostering sustainability competencies have been studied. However, research is rare on fostering systems thinking competence by simultaneously using multiple, real-world, and innovative learning approaches. To address this gap, we conducted a pre-test-post-test exploratory experimental study involving higher education students (n = 36). The study explored the contributions of field trips and collaborative learning in combination with mobile learning and paper-and-pencil note taking. The study simultaneously implemented a combined set of learning approaches in a real-world environment. The results suggest that the learning approaches and the real-world environment contribute to fostering the systems thinking competence of participants by exposing them to complex real-world systems and enabling the exchanging of diverse ideas among collaborating participants. As such, our study contributes to social constructivist learning discourses in education for sustainable development by indicating specific combinations of learning approaches and environments that facilitate the meaningful engagement and motivation of learners through self-regulated learning.