Use of Montmorillonitic Phimai Clay as Soil Conditioner in Sandy Paddy Saline Soil   Somsri Arunin. Panee Rungsaengchan. Charatsre Anantakul. Arunee Yuvaniyama and Chaiyanam Dissataporn   ABSTRACT        The experiment was carried out in the farmer's field during 1989-1993 at Mahasarakam province where the soil was sandy loam and infertile. The Treatments were clay saturated with Na and natural Phimai clay at the rates of 0.05, 0.1, 0.5, 1.0 and 2.0% of total soil weight of 20 cm. depth and compared with the control of the plough and unplough under a randomized complete block with 3 replications. Rice variety of KDML 105 were transplanted and rice yields were recorded. Infiltration rates, hydraulic conductivity and bulk density were determined after harvesting. The results showed that rice yields tended to increase with increasing rate of Na-clay and natural clay content while infiltration rate, hydraulic conductivity and bulk density tended to decrease. Rice yield was negatively correlated with infiltration rate, hydraulic conductivity and bulk density. However, they showed no significant differences between Na-clay and natural clay of the same rate, but they showed significantly different between plough and unplough of the controlled treatments.        Keywords : Phimaiclay (2:1), Paddy saline soil, rice