The Influence of combination Tithonia diversifolia compost and chicken manure with SP-36 fertilizer to P uptake and growth of maize on ultisol soil from labuhan batu selatan - Lubis, Mohd Fadli; University of Sumatera Utara (Program studi Agroekoteknologi, Fakultas Pertanian, Universitas Sumatera Utara-Medan, 2018)