Application of Symmetric Ploughs for Tillage on Wetland Paddy Fields

Impertinent uses of moldboard plows for tillage on wetland paddy soils, as far more than a century, caused damage to its important hardpan layer of 20-30 cm soil depth that led to some extent, the decrease of rice production than it should have been. The current study has been carried out to repair that damage to regain the “lost” of paddy yields by using the designed flat-symmetric plow that has a lift angle of 29°-30°. It is towed by a hand tractor of 12 horsepower (HP) at a travel speed of 1.11 m/s and a working depth of 10 cm in three blocks of a wetland paddy field in Bandung Sub-district of West-Java, Indonesia. Test results observed from the formed plow sole of 10-15 cm depth underneath after 3rd-time operations of the plow on the same track, indicated that there was a relatively small decrease of moisture content (MC) around 0.182%, as well as increases of cone index (CI) and bulk density (BD) around 0.172% and 0.171%, respectively. This plow was able to maintain, generate and stimulate the formation of hardpan right underneath the plow path. It was due to the improvement of hardpan physical-mechanical properties and would be more significant after frequent tillage using that plow. Hence, there is a chance to develop a tillage method in the development of an ideal wetland paddy cultivation system throughout Indonesian wetland paddy fields.