Assessment of Infiltration Rate under Different Drylands Types in

Assessment of infiltration rate for each type of soil in dryland areas need to do to get an idea of crop water requirement. The research objective was to analyze the infiltration rate on a various landuse, and the factors that affect the infiltration rate. Infiltration rate measurements were carried out on dryland areas of Unter Iwes District, Sumbawa regency; using the double ring infiltrometer. The undisturbed soil sample were used to determine physical characteristics of soil. The results showed that infiltration rate as high as 45.10 cm.h-1 and infiltration volume as high as 41.82 cm3 on rainfed landuse (it is the very-fast infiltration), the infiltration rate as low as 17.70 cm.h-1 and infiltration volume as low as 17.58 cm3 on ‘Tegalan ” landuse (it is the fast infiltration). Factors influencing infiltration are soil type, soil organic matter, porosity, bulk density, specific gravity and initial soil moisture content