When Deepak Ray and Jonathan Foley of the University of Minnesota looked at data for global harvest trends of 177 crops for the period 1961–2011, they found that between 2000 and 2011, the total area of land harvested increased four times more rapidly than the total area of cropland, suggesting that harvest frequency had increased.
The pair wondered if additional gains could be made by strategically increasing cropping frequency. The pair introduced the concept of the ‘harvest gap’ – the difference between actual per-year harvest frequency and the maximum potential frequency. They found that, on average, an extra harvest is being missed globally every two years, and that closing harvest gaps worldwide could boost production by more than 44 per cent.
The scientists acknowledge that the local impact of additional harvests, which would include deterioration of soil, water and the agricultural land base, would need to be taken into account before the harvest frequency could be substantially increased, and that these costs could prove to be prohibitive.
This story was published in the January 2014 edition of Geographical Magazine