About SOUMA KATSUYUKI
About MAEDA TAKASHI
About KASHIWAGI JUN'ICHI
About ITO YUKINORI
About IZUMI YOICHI
About 北海道庁
About FUJINO YOSHIHARU
About 北海道十勝支庁
About SUMITOMO HIROSHI
About 北海道土地改良事業団体連
About MARUYAMA KENJI
About 北海道農業開発公社
About 農業土木学会北海道支部研究発表会講演要旨集
About soil amendment
About Soil physics
About Soil management
About 畑
About 圃場
About 排水改良
About 排水
About 改良効果
About 土壌物理学