Arsenic-rich groundwater causes arsenic accumulation in arable soils for irrigation. For such arsenic-contaminated farmland, phytoremediation is a feasible method in terms of cost and maintenance of soil. We studied arsenic-rich farmland planted with maize, Rotala rotundifolia, and the arsenic super-accumulating plant Pteris vittata and explored the arsenic absorption capacity of these plants to assess the effect of phytoremediation on arsenic-contaminated farmland. The arsenic removal by Pteris vittata was about 200 mg/m² y. It would take about 90 years to reduce the soil arsenic below the regulatory standard of 60 mg/kg using Pteris vittata. Planting maize removed about 25.5 mg/m² y of arsenic, and the arsenic concentration of the maize kernels was less than 0.2 mg/kg on a dry basis. It was below the standards of the animal food and human consumption limit. Pteris vittata needs to be planted first to rapidly reduce the bioavailable arsenic concentration in the soil. Subsequent planting of maize for remediating the soil while producing corn enables the sustainable production and utilization of farmland.

Copper and zinc are metals commonly used in industry. However, improperly disposed copper and zinc pollute soil seriously. In farmland where the concentrations of copper and zinc exceeded regulatory standards and farming has been banned for many years, we measured the copper and zinc concentrations in soil. The copper concentration ranged from 30.2 to 1082.3 mg/kg, while the zinc concentration was between 200.2 and 3335.3 mg/kg. To explore the correlation between the concentration of copper and zinc in soil and plants and plant growth, Pennisetum was chosen as the test crop. The economic and carbon reduction benefits of planting Pennisetum in copper- and zinc-polluted farmland were also investigated. The results indicated that the concentration levels of copper and zinc were not significantly impacted, and neither was the growth of Pennisetum. Farming Pennisetum produces a total of about 1100 tons of biomass per hectare per year. The income per hectare was about USD 48,000 per year. Pennisetum captures 578.8 tons of carbon every year, equivalent to 2124.2 ton-CO₂e. When used as fuel, it provides 23,649 GJ of bioenergy. Therefore, Pennisetum is an appropriate plant for the green and sustainable remediation of polluted soil.