Soil Science - Study Mode
[#571] Soils are made up of minerals air, water and
Correct Answer
(B) Organic matter
Explanation
Solution: Soils are made up of minerals air, water and organic matter. Soil is commonly referred to as earth or dirt and is a mixture of organic matter, minerals, gases, liquids and organisms that support life. Soil consists of a solid phase of minerals and organic matter as well as a porous phase that holds gases and water.
[#572] A sequence of soils of about the same age, derived from similar parent material and occurring under similar climatic conditions, but having different characteristic due to variation in relief and drainage is called
Correct Answer
(B) Catena
Explanation
Solution: A sequence of soils of about the same age, derived from similar parent material, occurring under similar parent material and occurring under similar climatic conditions, but having different characteristics due to variation in relief and drainage is called Catena . The term catena was first coined by scientist Geoffrey Milne to describe these soil-topography units. A mature catena is in equilibrium as the processes of deposition and erosion are in balance.
[#573] Consider the following types of erosion 1. Gully erosion 2. Splash erosion 3. Normal erosion 4. Rill erosion 5. Sheet erosion The correct sequence in terms of the increasing order of soil loss from the field due to these types of erosion is
Correct Answer
(D) 3, 2, 5, 4, 1
Explanation
Solution: The correct sequence in terms of the increasing order of soil loss from the field due to these types of erosion is: Normal erosion < Splash erosion < Sheet erosion < Rill erosion < Gully erosion. Normal erosion is a fluvial procedure of upliftment of landmass as per sea level spread through geomorphic agents in glacial and arid areas. Splash erosion results from the bombardment of the soil surface by raindrops. Sheet erosion is the uniform removal of soil in thin layers. Rill erosion occurs when runoff water forms small channels as it concentrates down a slope. Gully erosion is a widespread and often dramatic form of soil erosion caused by flowing surface water.
[#574] Liming material passing through a 60 mesh sieve has efficiency (%)
Correct Answer
(D) 100
Explanation
Solution: Liming material passing through a 60 mesh sieve has an efficiency of 100%. Liming material with a CCE value greater than 1005 is more effective than pure CaCO 3 at neutralizing acidity. Liming materials are defined as all materials and all calcium and magnesium products in the oxide, hydrate, carbonate, silicate form or combinations thereof and intended for use in the correction of acidity of the soil.
[#575] Total number of master horizons present in soil are
Correct Answer
(A) 5
Explanation
Solution: The total number of master horizons present in the soil is 5. These are the O horizon, A horizon, B horizon, C horizon and E horizon. A soil horizon is a layer parallel to the soil surface whose physical, chemical and biological characteristics differ from the layers above and beneath. O horizon is soil layers with a high percentage of organic matter. A horizon is a mineral horizon formed at the soil surface, or below an O horizon. B horizon is a subsurface soil layer that is immediately beneath the A horizon from which it obtains organic matter chiefly by illuviation and is usually distinguished by less weathering. C horizon is the soil layer lying beneath the B horizon and consisting of the more or less weathered parent rock. E horizon has a lower clay content.