I think the answer is maybe. Previuos research howed that some bacteportria in soils play an important role in As accumulation in plants (e.g. rice). Amendment of organic matter into the soils might promote/supress the microbila community help plant to accumulate As. Instead, change the agricultural practice might help better, e.g. grow rice aerobically might decrease the accumulation of As.

Some studies found that organic matter can promote the As methylation in paddy soils. Besides growing rice aerobically, applying silicon fertlilizer can be an effective method to reduce arsenic accumulation in rice.

Thanks every one!