Crop thermotolerance is unaltered by farm diversity or soil amendment practices

Crop production on urban farms is challenged by stressful environmental conditions, notably high growing season temperatures. Management practices including intercropping and soil amendments may mitigate leaf-level heat stress on urban farms, though few studies have tested this expectation. We quantified leaf-level photosynthetic thermotolerance of bush beans (Phaseolus vulgaris) in an experimental urban farm under four different crop diversity and soil amendment treatments, across two growing seasons. Our results showed that leaf-level thermotolerance derived from chlorophyll fluorescence were largely unaffected by soil amendment and crop diversity practices, indicating constrained intraspecific variation in bush bean thermotolerance in urban agroecosystems.