Using soil amendments to reduce microcystin-LR bioaccumulation in lettuce

Area of Science:

• Environmental Science
• Soil Science
• Ecotoxicology

Background:

• Microcystins (MCs) contamination in the plant-soil system poses global risks.
• Understanding methods to reduce MCs bioaccumulation in edible plants is crucial.

Purpose of the Study:

• To evaluate the efficacy of soil amendments (attapulgite, biochar, peat) in reducing microcystin-LR (MC-LR) bioaccumulation in lettuce.
• To investigate the impact of these amendments on MC-LR bioavailability and soil microbial communities.

Main Methods:

• Lettuce was grown in two soil types irrigated with MC-LR, with and without soil amendments.
• MC-LR concentrations in lettuce tissues and soil were quantified.
• Soil bacterial community diversity and composition were analyzed using high-throughput sequencing.

Main Results:

• All tested soil amendments significantly reduced MC-LR bioaccumulation in lettuce roots and leaves.
• Peat was the most effective amendment, reducing leaf MC-LR by up to 57.0%.
• Peat amendment increased soil bacterial α-diversity and the abundance of MC-degrading bacteria, correlating with reduced total soil MC-LR.

Conclusions:

• Soil amendments, particularly peat, are effective in mitigating MC-LR bioaccumulation in lettuce.
• Peat enhances soil microbial communities, potentially promoting MC-LR degradation and reducing its bioavailability.
• This study offers a viable strategy to manage risks associated with MCs-contaminated plants.