Abstract
Saline soil is one of the most crucial problems of arid and semiarid regions because it reduces growth of plant and microorganisms. In Thailand, the inland saline soils are found mostly in the northeastern part especially in Maha Sarakham Province where 85% of the province has geological characteristics as rock salt beds. Saline soil often experiences low soil fertility problems which multiply the adverse effects on plant growth. Interestingly, the Na Si Nuan Secondary Forest, Kantharawichai District, Maha Sarakham, is not affected by salinity although almost the entire province of Maha Sarakham is salt-affected area. Saline soil is a habitat of halophilic bacteria. Bacteria are the most important microorganisms contribute to soil fertility and soil health. Thus data regarding the density of culturable halophilic bacteria and soil properties in this forest soil is useful for reclamation of saline soil and helping to sustain the forest ecosystem.