Quantifying soil health and tomato crop productivity in urban community and market gardens

Food production in cities offers a framework for local self-reliance and resilience. However, there are concerns about urban soil quality and a general lack of data on productivity in urban gardens. This study investigated soil health via a comprehensive nematode food web analysis and crop productivity via tomato fruit yield in community and market gardens in Cleveland, Ohio, USA over a two-year period. Results revealed that market gardens had significantly higher soil organic matter (SOM) and NH4-N than community gardens in 2011. While there was no difference between market gardens and community gardens in terms of nematode abundances (except bacteria-feeding nematodes in 2011), market gardens had higher nematode combined maturity index than community gardens in 2011. However, plant-parasitic index was lower in market gardens than in community gardens in 2011. There was no difference in tomato fruit yield in either year between the garden types, but tomato growth responses including leaf dry weight ratio, and plant surface area differed between market and community gardens in 2012. Different weather and related soil and growing conditions likely contributed to the large variation observed between 2011 and 2012; still, soils in market gardens tended to support greater growth and yield than community gardens. Regardless, there was no direct evidence that the gardens were nutrient limited, thereby minimizing the potential for nutrient limitations to contribute to yield differences. Overall, fruit yield ranged from 1.47 to 15.72 kg/m(2), which is consistent with U.S. national average for commercial production systems.