Soil Science MCQ Question and Answer | Agriculture MCQ Question

Dry soil is soil having high soil consistency.
Soil consistency is the strength with which soil materials are held together or the resistance of soils to deformation and rupture. Soil consistency is measured for wet, moist and dry soil samples. The rating of soil consistency helps in describing a soil profile and is also used for estimating suitability for traffic and tillage.

Reduction reaction (NO₂ to NH₃) for nitrate assimilation by enzyme nitrite reductase takes place in Chloroplast.
In photosynthetic eukaryotes, nitrate assimilation is performed by two transport and two reduction steps: the first nitrate is transported into the cell, then a cytosolic Nitrate reductase (NR) catalyzes nitrate reduction nitrite, which subsequently is transported into the chloroplast, where the enzyme Nitrite reductase catalyzes its reduction to ammonium.

Gravitational potential is the water potential in the soil is always positive.
The gravitational potential is that portion of the total water potential that is due to the gravitational force field of the earth and is dependent on the vertical location of the water relative to the reference level.
The gravitational potential of soil water at each point is determined by the elevation of the point relative to some arbitrary reference level.

The optimum fertilizer dose maximizes profits. Fertilizers are substances of natural or synthetic origin supplied to the crops to increase their productivity.
Fertilizers enhance the growth of plants and fertilizers act to enhance the effectiveness of the soil by modifying its water retention and aeration.

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.

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.

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.

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 CaCO₃ 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.

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.

Dispersion of colloidal clay is caused by Sodium.
Dispersion is a purely chemical phenomenon, driven by the balance of cations in the soil.
The inorganic or clay colloidal complex of soils occurs as too fine particles and the organic colloidal complex happens in the form of humus particles. The general balance between calcium and magnesium to sodium determines dispersion.