Global Cereal Crop Production May be Maxed Out on 30 Percent of Farms

Recent research conducted by the University of Nebraska suggests that nearly one-third of global rice, wheat and corn crops have reached their maximum yields in farmers' fields.

The revelation raises concerns about the ability to meet food production needs amid a rising global population.

Production of cereal crops has decreased or plateaued recently, the researchers report, noting that the projections typically used to ensure food security amid a growing population are based on a constant increase in yield. The University of Nebraska research, published in the journal Nature Communications, suggests that a constant increase in cereal crop yield is unlikely given that about 30 percent of rice, corn and wheat crops around the world have reached maximum yield.

"Estimates of future global food production and its ability to meet the dietary needs of a population expected to grow from 7 billion to 9 billion by 2050 have been based largely on projections of historical trends. Past trends have, however, been dominated by the rapid adoption of new technologies - some of which were one-time innovations - which allowed for an increase in crop production," the University of Nebraska, Lincoln, said in a statement.

The UNL researchers suggest that future crop protections are too optimistic considering the one-time technological innovations that led to increased yield in the past.

For the research, UNL scientists Kenneth Cassman and Patricio Grassini, of the agronomy and horticulture department, and Kent Eskridge of the statistics department, analyzed past cereal crop yields in the countries with the greatest production of the crops.

Their analysis suggests that the projected linear crop production increase is unlikely: "The rate of yield gain has recently decreased or stopped for one or more of the major cereals in many of the most intensively cropped areas of the world, including eastern Asia, Europe and the United States," the researchers said.

According to the Institute of Agriculture and Natural Resource, this crop decrease amounts to crop stagnation in 33 percent of major rice-producing countries, and 27 percent of major wheat-producing countries.

In China, wheat crop yield remained constant, but the rate of increase for corn crops has fallen by 64 percent compared to levels 10 years ago. This decrease, the researchers report, comes despite a large investment by China in agricultural research and development, education and infrastructure for both wheat and corn crops. The data suggests that the rate of return on these investments is declining in China, the researchers said.

In a statement, the study authors said that "sustaining further yield gain likely would require fine tuning of many different factors in the production of crops. But this is often difficult to achieve in farmers' fields and the associated marginal costs, labor requirements, risks and environmental impacts may outweigh the benefits."