Trace element problems in relation to soil units in Europe /working party

aptitude des terres bore boro boron chimie du sol ciencia del suelo cinc classification des sols cobalt cobalto cobre copper cuivre data processing deficiencia de minerales fer fertilidad del suelo genetic soil types hierro iode iodine iron land suitability manganese manganeso mineral deficiencies molibdeno molybdenum oligoelementos procesamiento de datos sciences du sol soil soil chemistry soil classification soil fertility soil sciences sol suelo toxicidad toxicity trace elements yodo zinc