EXPERIMENT 01 Env Studies.docx

**[EXPERIMENT 1]** \* AIM: To determine the moisture content in a given soil sample. \* REQUIREMENTS: China dish, balance of precision.001gm, hot air oven, desiccators, soil sample, pestle and mortar. \* PRINCIPLE: Water contained in soil is called soil moisture. The water is held within the s...

**[EXPERIMENT 1]** \* AIM: To determine the moisture content in a given soil sample. \* REQUIREMENTS: China dish, balance of precision.001gm, hot air oven, desiccators, soil sample, pestle and mortar. \* PRINCIPLE: 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, plants can readily absorb soil water. Not all 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 impor- tant as medium for supply of nutrients to growing plants. The method is based on removing soil moisture by oven drying a soil sample until the weight remains constant. The moisture content is calculated from the sample weight before and after drying. Soil containing gypsum lose water of corystallization. on heating therefore the moisture content determined by this method will be affected by approximately 0.1%. for each 1% gypsum. If it is suspected the presence of gypsum in the soil then drying shouldn\'t be more than at 80°c temperature for 1 hours. \* IMPORTANT OF SOIL WATER : \(i) Soil water serves as a solvent and carrier of food nutrients for plant growth. \(ii) Yield of crop is more often determined by the amount of water available rather than the deficiency of other food nutrients. (iii) Soil water acts as a nutrient itself. \(iv) Soil water regulates soil temperature. \(v) Soil forming processes and weathering depend on water. \(vi) Micro-organisms require water for their metabolic activities. \(vii) Soil water helps in Chemical and biological activities. of soil. \(viii) It is a principal constituent of the growing plant \(ix) Water is essential for photosynthesis. \* PROCEDURE: \(i) Weight accurately a dry crucible (China dish) kept in the oven at 110°e overnight and cooled in desiccators. \(ii) Take, 10 to 20 gm of finely powdered soil sample in the same frucible. \(iii) keep the sample from oven and cool in desiccators. \(iv) Remeve the sample from oven and at 105% to 110℃ for 1 hours \(v) Take the weight again. \(vi) Repeat the process of Step 3 to 5 till a constant weight is found. \* OBSERVATIONS: \(i) The weight of empty China, dish (W1) = 63-408 (ii) The weight of sample before drying (wa)= \_\_\_\_\_ g \(G) Weight of Sample after drying (ws) = \_\_\_\_\_g \* CALCULATIONS: \_\_\_\_\_\_\_\_\_\_ \_\_\_\_\_ \_\_\_\_\_\_ MC (%)= \_\_\_\_\_ \*RESULT: The moisture present in the soil sample is \_\_\_\_\_\_%. \*PRECAUTIONS: \(1) The balance to be used in a barticular test will debend on the size of the sample. The balance should be accurate to within 0.03% of the weight of the sample (it) The Soil sample should be finely powdered before use. \(iii) The sample may be coumbled to assist drying but care is necessary to avoid loss of any soil \(iv) The soil sample used in determination of moisture Content should be discarded and should not be used in any other test. \* SIGNIFICANCE OF SOIL MOISTURE: Compared to other components of the hydrologic cute. the volume of soil moisture is small; nonetheless it of fundamental importance to many hydrological, biological and biogeochemical processes. Soil moisture. information is valuable to a wide range of government agencies and private companies concerned with weather. and Climate, runoff potential and flood central, soil eresion and slope failure Steservoir management, geotechnical engineering, and water quality Soil moisture is a key variable in Controlling the exchangt of water and heat energy between the land Surface and the atmosphere through evaporation and blant transpiration. As a result, soil moisture blays an important stole in the development of weather patterns and the production of proecipi fa Simulations with numerical weather prediction models have shown that improved characterization of surface soil moisture, vegetation and tempeza can lead to significant forecast improvements Soil moisture also strongly affects the amount of precipitation that runs off into nearby Streams and rivers Large-scale dry or wet surfare segion have been observed to impart positive feedback en subsequent precipitation patterns, such as in the extreme conditions over the central Uis during the 1988 drought and the 1993 floods. Soil moistule Information can be used for reservoir management. early warning of droughts, irrigation scheduling. and corop yield forecasting. VIVA QUESTION: 1 2 3 4 5