Soil Science MCQ Question and Answer | Agriculture MCQ Question

Among the given options, Urea is the nitrogenous fertilizer for the amide group. It contains nitrogen in amide form but this form of nitrogen is swiftly converted by soil microorganisms into ammonical form and then into nitrate form.
Urea is a white crystalline solid containing 46% of nitrogen as an animal feed additive and fertilizer.

Francis Bacon (1591 - 1624) is the scientist who suggested that the principal nourishment of plants was water. The main purpose of the soil was to keep plants erect and to protect them from heat and cold.
Water helps a plant by transporting nutrients through the plant. Nutrients are drawn from the soil and used by the plant. Water carries dissolved sugar and other nutrients through the plant.

“Horse hoeing husbandry” was written by Jethro Tull.
It is an essay on the principles of vegetation and tillage, designed to introduce a new method of culture, whereby the produce of land will be increased and the usual expense lessened. Together with accurate descriptions and cuts of the instruments employed in it.

During isomorphous substitution within the clay, two cations replaceable and replacing must have ionic radii within the range of 0 - 15%.
The process of replacing one structural cation for another of similar size is known as isomorphic substitution. This replacement represents the primary source of both negative and positive charges in clay minerals.

Rocks containing more than 65% SiO₂ are acidic.
Rocks with more than 65% of silica are called Felsic or acidic, those with between 55 and 65 percent silica are intermediate, and those with between 45 - 55% silica are mafic (Basic) and those with less than 45% are ultramafic.
Acidic magma solidifies in the crust commonly as granite and erupts as rhyolite lavas. Within an intrusion, crystals grow large within the magma chamber.

The exchangeable sodium percentage measures the production of cation exchange sites occupied by sodium.
The exchangeable sodium ratio (ESR) is the relative amount of the sodium ion present on the soil surface, expressed as a percentage of the total cation exchange capacity.
It is calculated as:

$${\text{ESR}} = \frac{{{\text{Exchangeable}}\,{\text{N}}{{\text{a}}^ + }}}{{{\text{Exchangeable}}\left( {{\text{C}}{{\text{a}}^{2 + }} + {\text{M}}{{\text{g}}^{2 + }}} \right)}}$$

The water balance approach was given by Thornwhite.
The law of water balance states that the inflows to any water system or area are equal to its outflows plus the change in storage during a time interval.
In hydrology, a water balance equation can be used to describe the flow of water in and out of a system. It can also be referred to as how an organism maintains water in dry or hot conditions.

SAR is the sodium adsorption ratio and is the measure of the amount of sodium relative to calcium and magnesium in the water extract from the saturated soil paste. It is the ratio of the sodium concentration divided by the square root of one-half of the calcium and magnesium concentration.
SAR of the normal soil is less than 15.

Urea is a source of nitrogen, an essential nutrient crucial for crop growth and development. It is the most important nitrogenous fertilizer in the country because of its high N content (46%).
The share of urea in the N production pattern is around 85%. Other Straight fertilizers, such as CAN and ammonium chloride account for only 2%. The share of N through DAP and other complex fertilizers is about 16%.

Potassium fertilizer containing the maximum quantity of potash is Muriate of potash.
It usually contains 60% K₂O. It is the most common source of potash for farm use and is also the main potash ingredient for compound fertilizers containing potassium.
MOP (Muriate of Potash) is a red-white crystal, completely soluble in water and therefore readily available to the crops.