Estimating crop yield is very important when constructing a farm operating budget. Widening irregularity in harvested grain yield is making this process more challenging. So what is leading to this variability?
A recently released report from a research team at IonE’s Global Landscapes Initiative reveals that historic climate variability accounts for nearly one-third of yield variability in the major food grain crops: corn, rice, wheat and soybeans. They examined newly available global crop yield data from 1979-2008, along with rainfall and temperature data.
Their analysis revealed a variability of 32-39% between years which could be explained by the climate changes. Globally, this is equivalent to about 24 tons of corn, 3.3 tons of rice, 10 tons of wheat, and 2.2 tons of soybeans. Their analysis also revealed that the impact of climate variation is greatest in the world’s most productive regions such as the U.S. Midwest. More than 60% of the yield variability can be explained by climate variability in the midwestern states.
This relationship has a large impact on the issue of global food security – a great growing season can result in an excellent crop and adequate food supply in the market, but poor growing weather can strain the food grain market.
The research team has plans to expand their study to see what aspects of climate are more important to yield variability. Understanding drivers of crop yield can help producers, farm managers, and policy makers target efforts to stabilize farmer income and food supply while boosting global food supply in a changing world.