Development of Soil Moisture Index for Planning Water Management in the State of Sikkim (India)

Soil moisture and soil temperature are two important parameters that have a wider implication on crop production. The drop of soil moisture and temperature has an impact involving climate, vegetation and drought. The presence of soil moisture does not ensure its availability to a crop but the force by which water is held by soil particle is important. The amount of work done to extract soil moisture is generally expressed as stress. It is necessary to understand the extent of stress for proper water resources management. The soil moisture index (SMI) is a criterion that denotes the extent of stress experienced by a crop. The temperature also has an impact on germination and production. In the present study, we developed a SMI for different locations in Sikkim. The index ranges from +5 to -5. The negative index indicates extreme stress. The study indicated during winter the index goes beyond-3. Considering wilting point stress as 500 and 700 kPa. The soil temperature was also observed to fall below 15 C. Further, it was observed that soil temperature and moisture are strongly correlated to each other. The SMI can play an important role in adopting suitable water management practices for improved crop production.