Threat to crop yields - Groundwater depletion revealed

A Nebraska-led study, drawing from three decades of data, highlights the concerning consequences of groundwater depletion on crop yields, particularly in regions susceptible to drought and changing climate conditions. 

The study emphasizes that the depletion of aquifers, even when they appear to contain sufficient water for irrigation, can lead to reduced crop yields. The severity of agricultural losses escalates as aquifers diminish in thickness, particularly affecting crops like corn and soybeans. 

The research findings stress the importance of policymakers, resource managers, and farmers reevaluating the availability of groundwater for crop irrigation, particularly in areas prone to recurrent droughts. 

The study's conclusions are based on an in-depth analysis of data from the High Plains Aquifer, the largest aquifer in the United States, spanning eight states, including Nebraska. Over the years, some regions within this crucial aquifer have experienced significant depletion due to extensive irrigation practices. 

The study underscores the vital role of irrigation in ensuring food security, especially in the context of extreme conditions like drought and the ongoing impacts of climate change. 

The researchers considered various factors, including aquifer thickness, county-level yields of corn and soybeans, and meteorological data. Their findings reveal that the well yield, or the available groundwater for irrigation, has a substantial influence on crop resilience. 

Areas with thicker aquifers (approximately 220 to 700 feet) maintained high irrigated yields even during severe water deficits. Conversely, regions with thinner aquifers (30 to 100 feet) experienced declining yields when water deficits reached 400 millimeters, a common occurrence in the Midwest. 

The reduction in irrigation in areas with thinner aquifers exacerbated agricultural losses, emphasizing the urgent need for sustainable aquifer management and policies that safeguard groundwater resources. 

The study underscores the importance of proactive measures to ensure long-term food security and enhance resilience against the challenges posed by climate change.