Quantitative relationships between forms of microelements in arable layer of lessive-type soil under the conditions of many year differentiated fertilization

analyse quantitative analytical methods arable soils barley capa arable del suelo cebada charbon de bois charcoal couche arable cultivos de invierno cultivos de primavera culture d'hiver culture de printemps farmyard manure fertilisation fertilizer application field experimentation fumier hordeum vulgare inorganic fertilizers muestreo oligoelementos orge papa poland pologne polonia pomme de terre potatoes quantitative analysis rotation culturale rotational cropping sampling soil soil solution soil types sol sol arable solanum tuberosum soluciones del suelo solution du sol spring crops statistical methods suelo suelos cultivables technique analytique tipos de suelos top soil trace elements trigo triticum aestivum type de sol wheats winter crops