Biochar Blended with Alkaline Mineral Can Better Inhibit Lead and Cadmium Uptake and Promote the Growth of Vegetables
Lianxi Huang,
Weisheng Chen,
Lan Wei,
Xiang Li,
Yufen Huang,
Qing Huang,
Chuanping Liu,
Zhongzhen Liu
Affiliations
Lianxi Huang
Laboratory of Plant Nutrition and Fertilizer in South Region, Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key, Ministry of Agriculture, Guangzhou 510640, China
Weisheng Chen
Laboratory of Plant Nutrition and Fertilizer in South Region, Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key, Ministry of Agriculture, Guangzhou 510640, China
Lan Wei
Laboratory of Plant Nutrition and Fertilizer in South Region, Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key, Ministry of Agriculture, Guangzhou 510640, China
Xiang Li
Laboratory of Plant Nutrition and Fertilizer in South Region, Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key, Ministry of Agriculture, Guangzhou 510640, China
Yufen Huang
Laboratory of Plant Nutrition and Fertilizer in South Region, Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key, Ministry of Agriculture, Guangzhou 510640, China
Qing Huang
Laboratory of Plant Nutrition and Fertilizer in South Region, Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key, Ministry of Agriculture, Guangzhou 510640, China
Chuanping Liu
Institute of Eco-Environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou 510650, China
Zhongzhen Liu
Laboratory of Plant Nutrition and Fertilizer in South Region, Laboratory of Nutrient Cycling and Farmland Conservation, Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key, Ministry of Agriculture, Guangzhou 510640, China
Three successive vegetable pot experiments were conducted to assess the effects on the long-term immobilization of heavy metals in soil and crop yield improvement after the addition of peanut shell biochar and an alkaline mineral to an acidic soil contaminated with lead and cadmium. Compared with the CK treatment, the change rates of biomass in the edible parts of the three types of vegetables treated with B0.3, B1, B3, B9, R0.2 and B1R0.2 were −15.43%~123.30%, 35.10%~269.09%, 40.77%~929.31%, −26.08%~711.99%, 44.14%~1067.12% and 53.09%~1139.06%, respectively. The cadmium contents in the edible parts of the three vegetables treated with these six additives reduced by 2.08%~13.21%, 9.56%~24.78%, 9.96%~35.61%, 41.96%~78.42%, −4.19%~57.07% and 12.43%~65.92%, respectively, while the lead contents in the edible parts reduced by −15.70%~59.47%, 6.55%~70.75%, 3.40%~80.10%, 55.26%~89.79%, 11.05%~70.15% and 50.35%~79.25%, respectively. Due to the increases in soil pH, soil cation-exchange capacity and soil organic carbon content, the accumulation of Cd and Pb in the vegetables was most notably reduced with a high dosage of 9% peanut shell biochar alone, followed by the addition of a low dosage of 1% peanut shell biochar blended with 0.2% alkaline mineral. Therefore, the addition of a low dosage of 1% peanut shell biochar blended with 0.2% alkaline mineral was the best additive in increasing the vegetable biomass, whereas the addition of 9% peanut shell biochar alone was the worst. Evidently, the addition of 0.2% alkaline mineral can significantly reduce the amount of peanut shell needed for passivating heavy metals in soil, while it also achieves the effect of increasing the vegetable yield.
