Study on Spacing of Earthen Cylinder as Subirrigation for Tomato Planting in Sandy Soil   Seri Chaturongkakul Somnuk Sritongchim and Amorn Intrawech   ABSTRACT         Study on spacing of earthen cylinder as subirrigation for tomato planting in sandy soil was conducted in Roi-et Land Development station in Nampong series between Feb. and Aug. 1990 by using RCB design 5 treatments and 4 replication T1 = conventional watering T2 = bury earthen cylinder spacing 1 foot T3 = bury earthen cylinder spacing 2 feet T4 = bury earthen cylinder spacing 3 feet T5 = bury earthen cylinder spacing 4 feet.       The result showed that tomato buried with earthen cylinder spacing 2 feet gave the maximum yields (3,047.93 kg/rai) and the moisture content was 10.42 % per week. While tomato buried with earthen cylinder spacing 1 foot yielded 2,847.81kg/rai and average moisture content was 12.92 % per week. But tomato with watering conventionally gave the lowest yield at 2,012.84 kg/rai and average moisture content per week about 7.58 %         Keywords : Earthen Cylinder, Tomato