Floristic differentiation of cereals agrophytocoenosis under different farming system in Lower Silesia [Poland]

agricultura tradicional agriculture biologique agriculture intensive agriculture traditionnelle botanical composition calidad cereal crops composition botanique cultivos de cereales cultivos de invierno cultivos de primavera culture d'hiver culture de printemps especies exploitation agricole explotaciones agrarias farming systems farms infestation intensive farming malezas mauvaise herbe organic agriculture plantaciones plantations poland pologne polonia quality soil soil types sol species spring crops suelo tipos de suelos traditional farming type de sol weeds winter crops