MINNEAPOLIS / ST. PAUL (11/25/2013) Harvesting existing cropland more frequently could substantially increase global food production without clearing more land for agriculture, according to a new study from the Institute on the Environment (IonE) at the University of Minnesota.
The study, published in Environmental Research Letters, tracked global harvest trends of 177 crops between 1961 and 2011. It found that the total amount of land harvested increased four times faster than the total amount of cropland between 2000 and 2011, suggesting that harvest frequency was on the rise. This led the authors to wonder if there might be additional gains to be had by strategically increasing cropping frequency.
"Could existing arable lands get more frequent harvests, and what is the upper limit?" asked Deepak Ray, lead author of the study. To answer that question, he introduced a new concept: harvest gap.
Harvest gap is the difference between actual per-year harvest frequency and the maximum potential frequency. Ray and the study's co-author, IonE director Jonathan Foley, estimated that on average an extra harvest is being missed globally every two years due to the presence of this harvest gap.
The researchers found that Africa, Latin America and Asia have the highest concentration of potential harvest gaps. Brazil, for example, which on average harvests its croplands nearly once per year, has a harvest gap of 0.9, suggesting that on its current arable lands a second harvest is possible each year. Closing the gap would boost crop production on existing croplands without resorting to further clearing for agriculture, and so could potentially reduce the pressure to destroy additional rain forest. Increased harvest frequency also holds potential for mitigating risk under a changing climate. Worldwide, the researchers found that closing harvest gaps worldwide could theoretically boost production more than 44 percent.
|Contact: Mary Hoff|
University of Minnesota