Research from the Lawrence Berkeley National Laboratory demonstrates how warming temperatures are going to affect California crop production. The study looked at five annual crops that are primarily produced in California. The lead author of the research paper, Alison Marklein explained to AgNet West that four different scenarios were used to predict what temperatures would be like by mid-century.
“We compared those temperature ranges with the temperatures that crops can grow at and determined when the temperatures would be appropriate for the crops for enough months in a row for the duration of that crops growing season,” said Marklein.
California crop production for vegetables such as broccoli and lettuce may actually benefit from warmer temperatures according to the study. Weather conditions on the central coast, where the majority of production takes place, may accommodate a longer window of production. Warming temperatures could provide winter conditions suitable for growing the crops.
“Their growing season can actually extend as the fall and spring season are bridged together by the winter,” Marklein noted. “So, it can be grown from the fall through the spring which actually provides more time and more flexibility in when the cool-season crops can be grown.”
According to the study, not all California crop production will fare as well as the cool-season crops. Carrot and cantaloupe production will be negatively impacted by higher temperatures to varying degrees. Of the crops that were looked at, the biggest risk created by warming temperatures is for tomato production.
“We found between 34 and 87 percent of the land historically used for tomatoes will have temperatures appropriate for them in the future. So, that means we could lose 13 percent of that land or 66 percent of that land,” said Marklein. “There is that really big range because there is some uncertainty in the future regarding climate change and especially human behavior and how we’re going to mitigate it.”
One of the mitigation techniques Marklein is referring to is irrigation. The research was centered on air temperatures and not crop temperature, so there is an opportunity to offset some of the negative impacts of higher temperatures with appropriate irrigation. Now a project scientist at UC Riverside, Marklein noted that the hope is to continue the research to include a broader range of crops.