Permeability study of Several Soil Types in Sunggal Sei Krio District and in PTPN II Tanjung Morawa District Deli Serdang Through Laboratory and Field test - Siregar, Sarip Muda; Program Studi Keteknikan Pertanian Fakultas Pertanian Universitas Sumatera Utara (Universitas Sumatera Utara, 2014)