Responses of Irish potatoes (Solanum tuberosum L.) to mineral and organic fertilizer in various agro-ecological environments in Kenya

abonos abonos fosfatados abonos nitrogenados abonos potasicos application rates azote dose d'application efficiency eficacia engrais engrais potassique farmyard manure fertilidad del suelo fertilizers fosforo fumier nitrogen nitrogen fertilizers papa phosphate fertilizers phosphore phosphorus pomme de terre potash fertilizers potasio potassium potatoes soil soil fertility sol solanum tuberosum suelo uses usos utilisation