[1] Univ Muhammadiyah Sumatera Utara, Fac Agr, Medan, Indonesia
[2] Univ Sumatera Utara, Fac Agr, Medan, Indonesia
[3] Univ Labuhanbatu, Fac Sci & Technol, Rantauprapat, Sumatera Utara, Indonesia
[4] Univ Sebelas Maret, Fac Agr, Dept Soil Sci, Surakarta, Indonesia
[5] Univ Mohaghegh Ardabili, Fac Agr & Nat Resources, Dept Agron & Plant Breeding, Ardebil, Iran