Soil Science MCQ Question and Answer | Agriculture MCQ Question

Triple super phosphate contains about 40 - 48% soluble monocalcium phosphate [(H₂PO₄)₂ • H₂O]. when it dissolves in water, its phosphorus is negatively charged (-1).
TSP fertilizers are preferred as starter fertilizers for low soils. It can be used for all plants that are grown in soils with low or moderate phosphorus availability. When phosphorus is applied less than required or applied phosphorus has low efficiency due to soil conditions.

Soil gases are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen. Oxygen is critical because it allows for respiration for both plant roots and soil organisms. The percentage of oxygen in the soil air is about 20.6.

Nutrient uptake is the amount of each nutrient required for the crop to complete its life cycle at a given yield level. The rate of nutrient uptake is independent of the rate of water uptake, but the concentrations of nutrients at root surfaces depend strongly on soil water content.
Nutrient uptake by crops is fastest during Active growth.

Nitrosomonas and Nitrobacter are chemoautotrophic organisms found in soil and water and are responsible for the oxidation of ammonium to nitrite by Nitrosomonas and nitrite to nitrate in the presence of Nitrobacter.
These are obligate autotrophs that can obtain energy only by the oxidation of inorganic substrates and that cannot assimilate simple organic substrates, such as acetate, in the same way as carbon dioxide.

In tree crops, fertilizer is not added near the trunk because of the presence of fewer roots in that area. When it comes to fertilizing trees arborists often recommend deep root fertilization. Deep root fertilization is a specialized application method used to help restore trees that are struggling or showing signs of decline, it also improves soil aeration.

Sedentary soil is soil remaining on the rock from which it has developed or on which they are situated.
Black soil is an example of sedentary soil. Black soils are mineral soils that have a black surface horizon, enriched with organic carbon. It is the third major group of soil found in India.

Geological erosion is also known as Natural erosion. It is the action of surface processes that removes soil, rock or dissolved material from one location of the Earth’s crust, and then transports it to another where it is deposited by the action of wind or water.
The geological type of erosion contributes to the formation of soils and their distribution on the earth's surface.

Ultisols are strongly leached, acid forest soils with relatively low native fertility. They are found primarily in humid temperate and tropical areas of the world.
Alfisols are moderately leached soils that have relatively high native fertility. These are primarily found in temperate humid and subhumid regions of the world.
Alfisols have at least 35% base saturation, meaning calcium, magnesium, and potassium are relatively abundant. This is in contrast to ultisols, which are the more highly leached forest soils having less than 35% base saturation. That means Ultisol is comparable with alfisol except for having low BS% where BS is base saturation.

Fe-EDDHA is the Fe-chelate suitable for application to crops grown on calcareous soils. This chelated iron helps in correcting iron deficiency in flowers, vegetables, shrubs, and trees.
EDDHA is a chelate that protects nutrients against precipitation in a wide pH range of 4 - 9. And the availability of iron to plants is reduced through preci[piatation of iron at high pH, or by high concentrations of phosphorus.

Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. It is a common material, making up to 45% of average modern mud, found in many river deltas and as wind-deposited accumulations.
Silt is made up of rock and mineral particles that are larger than clay but smaller than sand. It ranges from 0.002 to 0.05 mm in diameter.