Crop Yields (image) PLOS Caption Global Projections. Observed area-weighted global yield 1961 - 2008 shown using closed circles and projections to 2050 shown using solid lines for maize, rice, wheat and soybean. Shading shows the 90 percent confidence region derived from 99 bootstrapped samples. The dashed line shows the trend of the ~2.4 percent yield improvement required each year to double production in these crops by 2050 without bringing additional land under cultivation starting in the base year of 2008. Credit Deepak Ray Usage Restrictions With credit to source Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.