Speakers: Maarten van Ginkel (ICARDA), Rattan Lal (Ohio State University, SENR, USA), Sarah Park (CSIRO, Australia), Jennie Barron (SEI, Sweden)

The increasing demand for food and other plant-based products is putting an ever- increasing claim on the worlds natural resources. The availability of land and water per person are however, constantly decreasing because of population increase and the degradation of soil, water and the narrowing of the genetic resource base. Together with the declining progress in yield increases per unit area, the supply to demand ratio of agriculture based products may converge with decreasing capacity to cope with temporary shortages. The frequency of these shortages may even escalate due to growing environmental variability. The fragility of this new world food equilibrium may further increase, making the poor even more vulnerable to food shortages, as has recently manifested.

The need to increase the use efficiency of natural resources is evident and urgent. Production ecological principles are based on the notion that a production factor is most efficiently used when other required factors are at their optimum. Hence, inputs should be balanced to the crops’ needs in time and space, considering location-specific ecological conditions, to yield the highest returns on inputs. With the expected expansion of agricultural land during the coming decades, ever less favourable production conditions will have to be dealt with, where production factors will be well below optimal. Attaining high eco-efficiency of scarce resources will be a formidable challenge.

Papers
The background paper to this session provides an overview of various options to increase the “eco-efficiency” of agricultural systems. It analyses options for increasing use- efficiencies of land, water, nutrients and their interactions, for different spatial and temporal scales, and explicitly addresses risks associated with these options. It illustrates opportunities and constraints by describing systems with over-whelming soil fertility constraints in Africa, low efficiencies through excessive use of inputs in China, and highly variable environmental conditions in Australia.

The four speakers in this session will carry the suggestions of the background paper further by detailing options for increasing eco-efficiency from a soil and water perspective, and to better exploit and preserve genetic resources, while the impact of climate change on these various resources will be analysed.

Workshop objectives
The aim of this workshop session is to: