Studies have reported positive effects from biochar on crop production in degraded and nutrient–poor soils. The application of compost and biochar under FP7 project FERTIPLUS has had positive effects in soil humidity, and crop productivity and quality in different countries. Biochar can be designed with specific qualities to target distinct properties of soils. In a Colombian savanna soil, biochar reduced leaching of critical nutrients, created a higher crop uptake of nutrients, and provided greater soil availability of nutrients. At 10% levels biochar reduced contaminant levels in plants by up to 80%, while reducing total chlordane and DDX content in the plants by 68 and 79%, respectively. On the other hand, because of its high adsorption capacity, biochar may reduce the efficacy of soil applied pesticides that are used for weed and pest control. High-surface-area biochars may be particularly problematic in this regard; more research into the long-term effects of biochar addition to soil is needed.