Phytotoxicity assessment on corn stover biochar, derived from fast pyrolysis, based on seed germination, early growth, and potential plant cell damage

Abstract

The potential phytotoxicity of water extractable toxicants in a typical corn stover biochar, the product of fast pyrolysis, was investigated using an aqueous biochar extract on a soil-less bioassay with tomato plants. The biochar dosage of 0.0-16.0 g beaker(-1) resulted in an inverted U-shaped dose-response relationship between biochar doasage and seed germination/seedling growth. This indicated that tomato growth was slightly stimulated by low dosages of biochar and inhibited with higher dosages of biochar. Additionally, antioxidant enzyme activities in the roots and leaves were enhanced at lower dosages, but rapidly decreased with higher dosages of biochar. With the increased dosages of biochar, the malondialdehyde content in the roots and leaves increased, in addition with the observed morphology of necrotic root cells, suggesting that serious damage to tomato seedlings occurred. EC50 of root length inhibition occurred with biochar dosages of 9.2 g beaker(-1) (3.5th day) and 16.7 g beaker(-1) (11th day) (equivalent to 82.8 and 150.3 t ha(-1), respectively), which implied that toxicity to the early growth of tomato can potentially be alleviated as the plant grows.

Using bamboo biochar with compost for the stabilization and phytotoxicity reduction of heavy metals in mine-contaminated soils of China

“…Maximum of 123 and 131% increases in the shoot and root dry biomass of FC were reported in T4 (5% BB). Other researchers also reported the role of biochar in enhancing the dry weight of roots, stems and leaves of plants 10, 26 . The root dry biomass of Nicotiana tabacum increased by 63.9–128.2% compared to the control 27 .

Figure 5Effect of bamboo biochar on shoot and root dry biomass (g pot −1 ) of Brassica juncea .

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Phytotoxicity of Corncob Biochar before and after Heat Treatment and Washing

“…These indicators were significantly influenced by the biochar application rate, especially at the application rate of 30 t/ha or higher. It was also reported in previous studies that the biochar application rate had a significant impact on germination and seedling growth [25,68]. Therefore, it is very important to identify suitable application rates of biochar for various agricultural applications.…”

“…This can be explained by the addition of mineral nutrients from biochar ash [67]. Water extract from corn stover biochar was also found to increase the shoot dry weight of tomato seedlings [68]. It was determined that the biochar application rate had a significant impact on the DM content in all biochar treatments.…”

Biochar based on residual biomasses and its influence over seedling emergence and growth in vivarium of Capparis scabrida (Sapote)

“…Buss y Masek (2014) encontraron que los compuestos recondensados producidos durante la pirolisis del biocarbón tiene un efecto fitotóxico, por ende, a mayor cantidad de biocarbón mayor es la probabilidad de que el biocarbón ejerza un efecto fitotóxico. El efecto negativo de dosis excesivas de biocarbón sobre el crecimiento de diferentes especies vegetales también ha sido reportado por otros autores (Solaiman et al, 2011;Li et al, 2015). CC-B, 15% 0,4x10 5 2,7x10 5 0,5x10 5 T3 CC-B, 30% 1,40x10 5 1,00x10 5 9,00x10 4 T4 CH-B, 0% 2,0x10 5 1,4x10 5 1,4x10 5 T5 CH-B, 15% 1,4x10 5 0,1x10 5 0,7x10 5 T6 CH-B, 30% 3,7x10 5 0,6x10 5 0,9x10 5 T7 SH-B, 0% 0,3x10 5 7,2x10 5 4,0x10 5 T8 SH-B, 15%.…”