Rose Harris , Sanna Sevanto, Gordon West

• Utilizing marginal lands may help resolve the conflict between using land for food or increased biofuel production for climate change mitigation. 

• Poor soil quality in the Southwest can make it challenging to convert marginal lands for cultivation, but when used as a soil amendment, biochar can improve soil health and water retention. 

• Because solar power is a natural solution for green energy production in these arid, sunny climates, we hypothesized that the combination of biochar and shading provided by solar panels might be especially beneficial for plant growth and yield in the Southwest.

 In 2022, biochar addition to the plots resulted in higher water retention and cooler soil temperatures in the shaded plots, resulting in improved tomato plant growth, fruit production, water use efficiency, and stomatal conductance. 

• In 2023, when soil temperatures were higher and soil moisture was lower, biochar increased the maximum soil temperatures and decreased water retention. 

• Comparing the results of 2022 and 2023 suggests that the effects of biochar on soil may depend on the baseline of soil moisture, temperature, and biochar dose.