Study compares drip, furrow irrigation in organic production

In light of the current drought, many tomato growers are turning to water-efficient drip irrigation to increase yields and water use efficiency while decreasing weed pressure. However, the long-term implications of this transition for nutrient cycling, soil health, and carbon cycling and sequestration are unclear. Researchers at the Russell Ranch Sustainable Agriculture Facility in collaboration with Professor Amelie Gaudin’s lab at UC Davis have studied the effects of drip irrigation (single and double subsurface lines) vs. furrow irrigation on organic tomato production.

This video shares some key findings from the 2016 field season and was created for this year’s American Society of Agronomy annual meeting.

Video created by Jennifer Schmidt, Caitlin Peterson, Daoyuan Wang and Amelie Gaudin.

Results from the 2016 field season show that in contrast to previous years, yield and water use efficiency were lower under drip irrigation, highlighting the challenges posed by adapting this technology to organic systems which rely on mineralization of organic nutrient inputs. However, drip irrigation also decreased weed pressure, a main concern for organic growers, and altered distributions of nitrate, microbial activity, and salinity.

These results indicate that differences in water application between different irrigation systems affect nutrient cycling and other soil properties even over the course of a single growing season, and highlight the need for further research into potential long-term trade-offs of transitioning to drip irrigation systems.

Source: UC Davis Russell Ranch