Improvement of wet grasslands [agricultural drainage, economic study, farm reared cattle, Charolais]

beef cattle botanical composition bovin de boucherie composition botanique conduite des herbages economic analysis exploitation agricole explotaciones agrarias farm results farms fertilisation fertilizer application gain de poids ganado de carne ganancia de peso grassland management grazing manejo de praderas pastizal permanente pastoreo pastoreo rotacional permanent pastures prairie permanente productividad productivity profitability rentabilidad rotational grazing terre humide weight gain wetlands