EFFECT OF THE BALANCED AND NANO-COMPOSITE NPK FERTILIZER ON THE VITALITY OF THE EARTHWORM Octolasion cyanieum AND ITS EFFECT ON THE HISTOLOGICAL COMPOSITION OF THE MIDDLE OF THE BODYEFFECT OF THE BALANCED AND NANO-COMPOSITE NPK FERTILIZER ON THE VITALITY OF THE EARTHWORM Octolasion cyanieum AND ITS EFFECT ON THE HISTOLOGICAL COMPOSITION OF THE MIDDLE OF THE BODY