Global food production could be significantly increased with more frequent harvests, without having to use more land.
The data comes from a study, published in the journal Environmental Research Letters, carried out at the Institute on the Environment at the University of Minnesota.
Deepak Ray and Jonathan Foley gathered and examined data on the harvest trends of 177 crops around the world from 1961 to 2011.
They found that the amount of harvested land rose four times faster than the total amount of cropland from 2000 to 2011, suggesting that the land was being harvested more frequently.
The authors wondered whether there might be additional gains if cropping frequency were strategically increased.
Lead author, Deepak Ray wondered “Could existing arable lands get more frequent harvests, and what is the upper limit?”
Ray introduced a new concept to answer that question – “harvest gap”.
Harvest gap is the difference between how often an area of land is currently being harvested annually and its maximum potential frequency. A harvest gap of 1 means that land could have an extra harvest each year, if the gap is 0.5 an extra harvest is possible every two years.
Source: Environmental Research Letters
Ray and Foley calculated that globally an extra harvest is being missed every 24 months due to the presence of this harvest gap.
They found the widest harvest gaps in Asia, Latin America and Africa.
For example, Brazil has an average of one harvest per year and a harvest gap of 0.9., i.e. from its current fertile farmlands the country could get another harvest nearly once every year.
Global food production can be boosted by closing the harvest gap
If farmers focused on closing the harvest gap, they could increase crop production without needing to acquire more land. On a global scale this would significantly reduce the pressure to clear areas in rain forests for agriculture.
The authors say that more frequent harvests could potentially reduce the risks associated with a changing climate. If harvest gaps were closed around the world, global food production could theoretically be increased by at least 44%.
The researchers emphasized that their study only looked at 177 crops. In order to quantify the potential impact comprehensively, further studies are needed with access to more local data. They added that farmers would then have to weigh the benefits against the costs of extra harvests, “which may turn out to be prohibitive”.
Increasing crop harvest frequency would have to be done without causing soil erosion and drying up the land.
The authors wrote:
“Depending on local environmental conditions, agronomic practices and social contexts, increasing cropland harvest frequency could present a short-term gain in crop production, with long-term losses in agricultural yields and environmental conditions. Only if increasing frequency of harvests can be done sustainably is this strategy a potential way to address some of the challenges of crop production and food security.”
Increasing harvest frequency raises local incomes
According to the report the “Introduction of second crops, generally corn following the primary soybean crop, has increased local incomes across economic sectors.”
Cropping frequency has been increasing steadily in China, Brazil and India, but declining in several African countries over the last few years.
The authors say that more frequent cropping is a potentially powerful “3rd way” of boosting global food production. The other two are using up more land and increasing harvest yields.
“The challenge for our generation is to meet growing food demands without destroying our environment. Increasing cropland harvest frequency is another piece toward solving the global food security puzzle.”