Potential evaluation of different intercropping remediation modes based on remediation efficiency and economic benefits - a case study of arsenic-contaminated soil.

Hyperaccumulator-cash crop intercropping remediation is a research hotspot for heavy metal contaminated farmland, but few studies evaluated its feasibility based on practice. Field experiments and survey statistics were conducted to obtain parameters of / intercropping, and potential of intercropping remediation was evaluated based on remediation efficiency and economic benefits. The results showed that intercropping hyperaccumulator with cash crop (especially herbs) had a certain negative effect on remediation efficiency because of the influence on planting density and harvest times of hyperaccumulator; while trees could partly alleviate this effect. Until achieving the predetermined target, the net remediation cost of was 18.2 $/g As, followed by monoculture (13.3 $/g) and (8.6 $/g). Based on the proposed evaluation model, nealy half of the intercropping modes had low economic benefits, insufficient to compensate the cost of sacrificing remediation efficiency. Based on the data from two soil remediation projects, when net income of cash crops intercropped with As-hyperaccumulators exceeded 5865/1607 $/hm (herbs/trees), the economic benefit of intercropping will be relatively obvious. Therefore, cash crops should be considered from three aspects: planting conditions, spatial allocation and economic benefits. This work analyzed remediation efficiency and economic benefits of intercropping remediation. An economic benefit evaluation model was established to evaluate intercropping remediation modes. The selection principle and net income threshold of cash crops in intercropping was put forward for the first time.[Figure: see text]HighlightsThe selection principle of cash crops in intercropping remediation was put forward.An evaluation model of intercropping remediation was established.The net cost of extracting 1.0 g of soil As in each remediation mode was proposed.Net income of herb/tree intercropped with should exceed 5865/1607 $/hm.