Influence of pear tree biochar on the growth and oxidative stress of Yunnanopilia longistaminea - A forest vegetable planted in copper-contaminated soil

Abstract

Biochar, an environmentally sustainable material, has been extensively used for the remediation of degraded soils. Yunnanopilia longistaminea is an edible plant and a valuable germplasm resource with significant economic importance in China. This study explored the potential of adding pear tree twigs biochar (PTB) to copper (Cu) contaminated soils, examining its effects on the growth and oxidative stress of Yunnanopilia longistaminea, as well as on soil health. A glasshouse study was conducted to find the efficacy of PTB at 0 %, 1 %, 3 %, and 5 % w/w on Y. longistaminea seedlings growth, oxidative stress, Cu uptake and post-harvest soil characteristics. The addition of PTB to the soil significantly improved seedling growth, as evidenced by increased fresh biomass, plant height, and SPAD readings, while also reducing the available Cu content in the soil. Chlorophyll in leaves was significantly high at 3 % w/w PTB rate, compared with the control. Moreover, 3 % PTB addition resulted in a significant reduction in oxidative stress and increase in soluble sugars and proteins. Furthermore, a prominent decline was detected in Y. longistaminea root, leaf, and stem Cu contents. Thus, PTB showed positive results for Cu immobilization in contaminated soil by improving soil electrical conductivity and reducing Cu uptake in Y. longistaminea seedlings. A negative correlation was observed between plant biomass and available Cu in soil. Our results highlight the significance of Y. longistaminea plantation using PTB in Cu contaminated soils.