Nitrogen fertilizer ameliorate the remedial capacity of industrial hemp (Cannabis sativa L.) grown in lead contaminated soil

Industrial hemp (Cannabis sativa L.) is a fibrous plant with high biomass production, and can survive under heavy metal stress conditions. To determine the growth potential of industrial hemp on lead (Pb) contaminated soil, a pot experiment was conducted using two varieties Bamahuoma (BM) and Yunma-1 (Y1), under different levels of nitrogen (N) fertilizer viz., 0 (control), 0.1, 0.3, 0.5 and 0.7 g kg(-1). The soil was artificially spiked with Pb using PbCl. Lead uptake and its accumulation in different organs of both hemp varieties were analyzed. Increasing level of N fertilizer caused a significant increase in the plant growth and dry biomass production in both varieties, while Y1 showed more tolerance to Pb, than BM. Furthermore, N (%) was higher in the leaves and stems then in the roots. Contrastingly, Pb was highly accumulated in the roots then in the leaves and stems of both varieties under varying levels of N fertilizer in the soil. Lead uptake and its accumulation in different plant parts were increased with the increase in N fertilizer in the soil. Hence, these findings indicate that external N fertilization is a useful strategy to enhance dry biomass and Pb accumulation in industrial hemp.

Automated summary

The study found that increasing nitrogen fertilizer levels can significantly improve the growth and dry biomass production of industrial hemp, and increase the accumulation of lead in the plant. The nitrogen content in the leaves and stems was higher than in the roots, while lead accumulation in the roots was higher than in the leaves and stems.