Sustainable intensification in agriculture: the richer shade of green. A review

Agricultural intensification is required to feed the growing and increasingly demanding human population. Intensification is associated with increasing use of resources, applied as efficiently as possible, i.e. with a concurrent increase in both resource use and resource use efficiency. Resource use efficiency has agronomic, environmental, economic, social, trans-generational, and global dimensions. Current industrial agriculture privileges economic resource use efficiency over the other dimensions, claiming that that pathway is necessary to feed the world. Current agronomy and the concept of sustainable intensification are contested. Sustainable intensification needs to include clarity about principles and practices for priority setting, an all-inclusive and explicit cost-benefit analysis, and subsequent weighing of trade-offs, based on scientifically acceptable, shared norms, thus making agriculture green again. Here, we review different forms of intensification, different principles and concepts underlying them, as well as the norms and values that are needed to guide the search for effective forms of sustainable and ecological intensification. We also address innovations in research and education required to create the necessary knowledge base. We argue that sustainable intensification should be considered as a process of enquiry and analysis for navigating and sorting out the issues and concerns in agronomy. Sustainable intensification is about societal negotiation, institutional innovation, justice, and adaptive management. We also make a plea for at least two alternative framings of sustainable intensification: one referring to the need for de-intensification in high-input systems to become more sustainable and one referring to the need to increase inputs and thereby yields where there are currently large yield (and often also efficiency) gaps. Society needs an agriculture that demonstrates resilience under future change, an agronomy that can cope with the diversity of trade-offs across different stakeholders, and a sustainability that is perceived as a dynamic process based on agreed values and shared knowledge, insight, and wisdom.