About Soil Moisture

About Soil Moisture

  • Water contained in soil is called soil moisture. The water is held within the soil pores.
  • Soil water is the major component of the soil in relation to plant growth.
  • If the moisture content of a soil is optimum for plant growth, plants can readily absorb soil water.
  • Not all the water, held in soil, is available to plants. Much of water remains in the soil as a thin film.
  • Soil water dissolves salts and makes up the soil solution, which is important as medium for supply of nutrients to growing plants.


Importance of Soil Water

  • Soil water serves as a solvent and carrier of food nutrients for plant growth
  • Yield of crop is more often determined by the amount of water available rather than the deficiency of other food nutrients
  • Soil water acts as a nutrient itself
  • Soil water regulates soil temperature
  • Soil forming processes and weathering depend on water
  • Microorganisms require water for their metabolic activities
  • Soil water helps in chemical and biological activities of soil
  • It is a principal constituent of the growing plant
  • Water is essential for photosynthesis


Soil Moisture Forecast

  • Based on observed conditions at present, Gujarat, parts of Maharashtra, Chhattisgarh, Jharkhand, Tamil Nadu and parts of Andhra Pradesh are deficient in terms of soil moisture right now.
  • This means that if there is not enough rainfall in one or two months, these are regions which will demand heavy irrigation whether that comes from groundwater or surface water storage (reservoirs)

  • In Gujarat, a look at the monsoon season rainfall this year shows rainfall deficit, while the Narmada basin also received inadequate rainfall.
  • The Sardar Sarovar reservoir may not have received enough storage and since the catchment of the reservoir did not receive normal rainfall.
  • In these conditions, the state may face water stress, which can result in excessive groundwater pumping for irrigation.
  • Forecasts for the Bundelkhand region look favourable at the moment. In Uttar Pradesh and northern Madhya Pradesh, this year, the rainfall was good.
  • Tamil Nadu is showing dry conditions but if the state gets good rain from the Northeast monsoon, the current soil moisture deficit is likely to go away.


Techniques used in forecasting

  • The forcast uses the ‘Variable Infiltration Capacity’ model to provide the soil moisture prediction.
  • The product, termed ‘Experimental Forecasts Land Surface Products’ has been developed using the hydrological model that takes into consideration soil, vegetation, land use and land cover among other parameters.
  • At present, the IIT Gandhinagar team is using the IMD’s grid-level observations and forecast products of rainfall and temperature.
  • The product has become operational on an experimental basis that will be further enhanced based on the inputs from the stakeholders.


Significance of the soil- moisture forecast

  • Crucial information needed for agriculture is not revealed only through rainfall data
  • Even if you have a normal rainfall, if the temperature is abnormally high, it can rapidly deplete the soil moisture. So essentially soil moisture gives us more information on what is needed for crop growth in different parts of the country.
  • Soil moisture is crucial for agriculture since it directly affects crop growth and how much irrigation is required for the area.
  • Timely soil moisture forecasts will help target interventions, in terms of seed varieties for better planning in agriculture.



Section : Environment & Ecology