Pyrolytic biochars from sunflower seed shells, peanut shells and Spirulina algae: their potential as soil amendment and natural growth regulators

SILVA, MARIANA P.; NIEVA LOBOS, MARÍA L.; PILONI, ROXANA V.; DUSSO, DIEGO; GONZÁLEZ QUIJÓN, MARÍA E.; SCOPEL, ANA L.; MOYANO, ELIZABETH L.

SN Applied Sciences

Springer Nature

Año: 2020 vol. 2

everal studies have shown that pyrolysis conditions and feedstocks are the key factors influencing biochar chemical and physical properties. The information on the nature of biochar is quite important, especially when this carbonaceous material is intended to be used as a potential soil amendment. In this study, we investigated the formation and characterisation of biochars produced from vacuum pyrolysis of sunflower seed shells (SSS), peanut shells (PS) and Spirulina algae (Sp) at 280 °C (for SSS, PS and Sp) and 350 °C (for PS). As a proxy to test the potential of each biochar as soil amendment, we assessed the germination and growth effects of the biochar water-extractable substances (BWES) at different concentrations (10; 7.5; 5; and 2.5% w/v) on Lactuca sativa. Results showed that the biochar from pyrolysis of PS at 280 °C would be the most suitable soil amendment, since its BWES did not affect germination and exhibited a remarkable growth-promoting effect (50?100%) on roots and s