Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China.
Sci Rep. 2022 May 4;12(1):7268. doi: 10.1038/s41598-022-11170-3.
Phosphorus (P) deficiency in agricultural soil is a worldwide concern. P modification of biochar, a common soil conditioner produced by pyrolysis of wastes and residues, can increase P availability and improve soil quality. This study aims to investigate the effects of P-modified biochar as a soil amendment on the growth and quality of a medicinal plant (Pseudostellaria heterophylla). P. heterophylla were grown for 4 months in lateritic soil amended with P-modified and unmodified biochar (peanut shell) at dosages of 0, 3% and 5% (by mass). Compared with unmodified biochar, P-modified biochar reduced available heavy metal Cd in soil by up to 73.0% and osmotic suction in the root zone by up to 49.3%. P-modified biochar application at 3% and 5% promoted the tuber yield of P. heterophylla significantly by 68.6% and 136.0% respectively. This was different from that in unmodified biochar treatment, where tuber yield was stimulated at 3% dosage but inhibited at 5% dosage. The concentrations of active ingredients (i.e., polysaccharides, saponins) in tuber were increased by 2.9-78.8% under P-modified biochar amendment compared with control, indicating the better tuber quality. This study recommended the application of 5% P-modified biochar for promoting the yield and quality of P. heterophylla.
土壤中磷（P）缺乏是一个全球性问题。生物炭是一种通过废物和残渣热解产生的常见土壤调节剂，对其进行 P 改性可以增加 P 的有效性并改善土壤质量。本研究旨在研究作为土壤改良剂的 P 改性生物炭对一种药用植物（太子参）生长和质量的影响。在红壤中添加 0、3%和 5%（按质量计）的 P 改性和未改性生物炭（花生壳），将太子参种植 4 个月。与未改性生物炭相比，P 改性生物炭可使土壤中有效重金属 Cd 的含量降低多达 73.0%，根区的渗透压降低多达 49.3%。P 改性生物炭的添加量为 3%和 5%时，分别显著促进了太子参块茎产量提高 68.6%和 136.0%。这与未改性生物炭处理不同，未改性生物炭在 3%添加量时刺激块茎产量，但在 5%添加量时抑制块茎产量。与对照相比，P 改性生物炭处理下块茎中活性成分（即多糖、皂苷）的浓度提高了 2.9-78.8%，表明块茎质量更好。本研究建议应用 5%的 P 改性生物炭来提高太子参的产量和质量。
