Comparison of weed infestation of cereal crops on selected organic and traditional fields in Slowinski National Park [Poland]

agricultura tradicional agriculture biologique agriculture traditionnelle campo cereal crops champ cultivos de cereales cultivos de invierno cultivos de primavera culture d'hiver culture de printemps especies exploitation agricole explotaciones agrarias farming systems farms fields infestation malezas mauvaise herbe organic agriculture poland pologne polonia sandy soils sol sableux species spring crops suelo arenoso traditional farming variedades varieties weeds winter crops