Sustainable intensification: overcoming land and water constraints on food production

Feeding over 9 billion people by the second half of this century will require a major paradigm shift in agricultural systems. Agriculture uses approximately 40 % of the terrestrial surface, is the major user of fresh water resources and contributes 17 % of greenhouse gas emissions. In turn, agriculture will be detrimentally affected by climate change in many climatic regions. Impacts of agriculture on ecosystem services include land clearing, loss of forest cover and biodiversity, significant soil degradation and water quality decline. Agricultural production will have to increase, even if we can reduce the rate of increase in demand for food. Given the current pressures on natural resources, this will have to be achieved by some form of agricultural intensification that causes less environmental impact. Therefore, it is not just intensification of agriculture, but 'sustainable intensification' that must be at the forefront of the paradigm shift. There is also a need to assess the situation holistically, taking into account population growth and resource intensive consumption patterns, improved systems of governance, changing diets and reducing waste. We review how and where natural resources are being placed under increasing pressure and examine the "ecological footprint" of agriculture. Suggested solutions include the application of existing scientific knowledge, implementation of emerging principles for sustainable land and water management and reclamation of salinized land. Encouragement of community action and private sector supply chain and production codes, backed up by improved national and regional governance and regulation also need to be encouraged if we are to see agricultural production become truly sustainable.