Physicochemical Properties of Soils as Affected by Minimum Tillage and Direct Seeding Cultivation on Dry Rice Paddy

In order to evaluating physiochemical properties of soil under minimum tillage and direct seeding cultivation on dry rice paddy, we conducted to analyze the soil physiochemical characteristics in treatment with 2-year minimum tillage and dry direct seeding (2MT), 3-year minimum tillage and dry direct seeding (3MT), and tillage transplanting cultivation (TT). As results of analyzing soil organic matter (OM) contents with 2 cm soil depth of interval from surface to 30 cm, OM contents with surface soil from 0 to 2MT and 3MT were higher than TT, recorded 34.6, 28.1 and $19.8gkg^{-1}$, respectively. But until 20cm in soil depth, it was not so large on the deviation of OM contents among the 3 treatments comparing with 2cm surface. Beneath 20 cm in soil depths, 2- and 3-year, OM contents in TT were distributed to be lower than 2MT and 3MT. The contents of total nitrogen in 2MT and 3MT were higher than the content in TT across the soil profile. Consequently, though minimum tillage and direct seeding farming is obviously the practice to saving of machinery work and labor, other practices such as continuously input OM should be needed to achieve carbon sequestration goal through minimum tillage and direct seeding on dry paddy.