NPK = Nitrogen, and Potassium Phospor Is a compound fertilizer NPK ( in a few species fertilizers containing nutrients) required in growing plants. Usability Buana Tjakra NPK fertilizer are: N ( nitrogen) = required to stimulate vegetative growth the plant prior to having a production P ( phospor) = useful to stimulate the formation of flowers and fruit K ( potassium) = strengthen the roots of flowers and fruit