Not since the Green Revolution half a century ago has there been such a golden age for agronomy.  But unlike the hey-day of new high-yield varieties of rice, wheat and corn, there is no consensus today about where the science of farming should be headed and what it should be trying to deliver.

Is the aim to maximise yield, to feed the world’s growing urban masses, to improve the lot of rural households, to rescue the world’s soils from rampant over exploitation, or to drive economic growth in developing economies?