Stabilize the food production of countries by the diversity of cultures

Faced with the growing food demand of the planet's growing population and climate change threatening the stability of food systems around the world, research from the University of Minnesota has shown how crop diversity at the national level can increase the stability of the crop of all crops of a country.

The research, published Wednesday in the newspaper Nature, reviewed 50 years of data (1961-2010) provided by the Food and Agriculture Organization of the United Nations (FAO) on annual yields of 176 species grown in 91 countries in order to determine the level of stability and predictability of the food supply in each country. This study is the first of its kind to examine the relationship between crop diversity and food stability at the national level.

"We found an intriguing pattern: countries that grow more plants generally have more stable food supplies," said G. David Tilman, co-author of this study and director of the Cedar Creek Ecosystem Science Reserve at the College of Biological Sciences. "Our badysis also shows that countries with a variety of crops are less likely to experience a severe shortage of food."

This type of shortage is described as a year in which a country has experienced a decline in yield of 25% or more of the total yield of all its crops combined. After reviewing the data from FAO, Tilman and Delphine Renard – a postdoctoral researcher at the University of California at Santa Barbara – found that:

• countries with some of the lowest crop diversity experience a severe food shortage about every eight years;
• countries where crops are among the most diverse are experiencing a severe food shortage about every 100 years;
• The robust irrigation capabilities of countries also have significant stabilizing effects on crop production, reducing the number of years of food shortage.

Research suggests that countries that increase crop diversity appropriately may have more stable food availability. In areas of the world where water resources are limited or where increased irrigation is unaffordable, researchers suggest that a greater diversity of crops can be particularly useful because it allows farmers not only to stabilize their food supply, but also their income.

The research also revealed:

• that the stability of a country's food supply depended on the type of crop, with cereals and legumes appearing to lead to more stable food supplies;
• the stability of food supplies depended not only on the multiplication of harvests, but also on their abundance;
• Heat waves affected yields and stability, and although fertilization significantly increased yields, it did not increase stability.

"Food supplies are expected to become less stable because of climate change," Tilman said. "We encourage countries around the world to badess the diversity of their crops and to determine if other crops might be suitable for them." Increasing crop diversity is one of the tactics for achieving prepare for the potential impacts of climate change on crop production. "

Tilman suggests that, in conjunction with crop diversity planning, countries should consider the benefits of new varieties of drought-resistant crops, increased irrigation, badociated crops and a trade agricultural more transparent.

"There are 7.7 billion people on Earth and we all depend on a stable global food supply," Tilman said. "These tactics are just one of many actions we can take to plan our future and better prepare future generations to live healthfully on this planet."

Future research needs to be undertaken to understand which types and combinations of crops are best suited to specific climates and soils to improve the stability of the food supply.