The Effect of Conservation Practice on Soil Moisture of Agricultural Basin   Ratana Jindapol, Rungkarn Krishnamra, Piboon Srisakunl and Uthai Somsopon   ABSTRACT         The comparison of soil moisture characteristic between conservation watershed and non-conservation watershed in every ten days during 1998 to 1991 in Chonburi province, it is found that the conservation practice surely could preserve soil moisture content in the watershed. Although the soil texture and average annual rainfall of the non-conservation watershed were better than conservation watershed, but the soil moisture at 30 to 60 cm. Depth on the graded terrace conservation watershed showed that it could save water amount for plants at field capacity about 110,820 cm.3/year/km.2 or could estimate cost for pumping water about 27,705 baht/year/km.2.         Keywords : Conservation practice, Soil moisture