Soil Science MCQ Question and Answer | Agriculture MCQ Question

Atmospheric pressure is measured by Barometer. However, the most accurate instrument used to measure atmospheric pressure is a Fortin-type Barometer.
Fortin Barometer is the most commonly used barometer for calibration duties. It is a highly accurate instrument that provides measurement inaccuracy levels of between ±0.03% of full-scale reading and ±0.001% of full-scale reading depending on the measurement range.

An illite is a group of closely related non-expanding clay minerals. It is a secondary mineral precipitate, and an example of phyllosilicate, or layered alumino-silicate. Its structure is a 2 : 1 sandwich of silica tetrahedron-alumina octahedron-silica tetrahedron.
The y-index value for illitic clay is between 5 - 25.

The soil is well flocculated if it has more Calcium.
Flocculation is a process during which soil particles are dispersed in a solution contact and adhere to each other, forming clusters, flocks, flakes or clumps of a larger size. Soil particles will flocculate if the amount of soluble salts in the soil is increased.

Morocco is the country that has a monopoly in P deposits.
Morocco claims 75% of the planet’s known reserves of phosphorus, an essential ingredient in commercial fertilizer. It gives the North African country a near-monopoly on the multibillion-dollar global trade of the mineral mined from phosphate rock, with clients on every continent.

Superphosphate is a component fertilizer that primarily consists of monocalcium phosphate, Ca(H₂PO₄)₂. SSP is the most popular phosphatic fertilizer after DAP as it contains 3 major plant nutrients namely Phosphorus, Sulphur and Calcium along with traces of many micro-nutrients.
Fertilizers SSP dissolve in the soil to furnish Phosphate, Calcium and Sulphur.

The critical limit of available phosphorus in soil for the wheat crop by Olsen's method is 10 kg/ha.
Olsen’s method is done for the estimation of phosphorus and is based on the extraction of phosphate from the soil by 0.5 N sodium bicarbonate solution adjusted to pH 8.5. this procedure is suitable for calcareous, alkaline, neutral, and slightly acidic soils containing CaPO₄.

An alluvial fan is an accumulation of the sediments that fan outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. This accumulation is shaped like a section of a shallow cone, with its apex at the source of sediments.
An alluvial fan is seen in India near Haridwar as it is along the Himalayas mountain front on the Indo-Gangetic plain.

Calcium Cyanamide is the inorganic compound with the formula CaCN₂. It is the calcium salt of the cyanamide anion. In contact with water, it decomposes and liberates ammonia.
This is widely used as nitrogen fertilizer and is also known as Nitrolime. It contains about 21% nitrogen.

Humus is the organic component of the soil. The charge on humus colloids is dependent on pH. It mostly exhibits a low negative charge. Under strongly acid conditions hydrogen is rigidly bound and not easily replaceable by other cations.
The major source of negative charge on humus colloids is due to carboxylic, enolic, and phenolic groups.

Biogas is a mixture of gases, like methane, carbon dioxide, hydrogen sulphide siloxanes, etc. but the main constituent of Biogas is Methane.
It is produced from raw materials such as agricultural wastes, manure, municipal waste, plant material, sewage, green waste and food waste. It is a renewable source of energy.