Organic waste is increasingly being used as a fertilizer and amendment on market garden crops.

It improves soil physical properties, reduces runoff and erosion and boosts the amount of organic carbon and other major elements, while reducing mineral fertilizer use and increasing biomass and microbial activity.

However, it can also have an adverse effect on crops and the environment, due to the presence of potentially toxic substances: heavy metals.

A team from CIRAD and CEREGE (INTERFAST) analysed a range of types of organic waste to determine their toxic element composition and determine the origin.

http://www.cirad.fr/en/research-operations/research-results/2014/agricultural-recycling-of-waste-what-are-the-risks-for-market-garden-crops