Soil Science MCQ Question and Answer | Agriculture MCQ Question

A developed soil or mature soil has three soil horizons whose physical, chemical, and biological characteristics differ from the layers above and beneath which help in nutrient supply and proper development of the plant.
The A horizon is the top layer of the mineral soil horizons, often referred to as "topsoil."
The B horizon is referred to as subsoil and consists of mineral layers which are significantly altered by pedogenesis.
The C horizon is below the solum horizons. The C horizon is enriched with carbonates carried below the solum by leaching.

Alkali soils are clay soils with high pH. A poor soil structure and a low infiltration capacity. Alkali soils owe their unfavorable physio-chemical properties mainly to the dominating presence of sodium carbonate, which causes the soil to swell and difficult to settle.
Alkali soils are very common in semi-arid and arid climates and cover more than 25% of the earth's surface.

The phosphorous solubilizing fungi are such fungi that can act on the phosphorous present in the organic matter of the soil and make it available for plant use.
The isolated phosphate solubilizing fungi belonged to the genera of Aspergillus (55.69%), Penicillium spp. (23.35%) and Fusarium (9.8%).
So, out of the given options, Aspergillus is phosphorus solubilizing fungi.

A solum (plural, sola) in soil science consists of the surface and subsoil layers that have undergone the same soil forming conditions.
In terms of soil horizon designations, a solum consists of A, E and B horizons and their transitional horizons and some O horizons.

Stacking of bags needs to be done in a proper format, stack the bags evenly against at least two supporting walls. Supported stacking should be used whenever possible to ensure the maximum amount of stability.
The height of a stack of bags should not be more than 20 bags.

Sea surface temperature or ocean surface temperature is the water temperature close to the ocean's surface. The range of sea surface varies between 1 millimeter and 20 metres below the sea surface.
The mean sea surface temperature is around 23°C, but our ranges from more than 30 degrees Celsius in warm tropical regions to less than zero degrees Celcius at high altitudes.

Vermiculite is a group of colloids that have the highest cation exchange capacity by volume basis.
Vermiculite is a hydrous phyllosilicate mineral that undergoes significant expansion when heated. It is formed by the weathering or hydrothermal alteration of biotite or phlogopite. It helps to aerate the soil while simultaneously retaining water and nutrients.

The availability of P₂O₅ is maximum at neutral pH.
P₂O₅ is listed as 'available phosphate'. The sum of the water-soluble and citrate-soluble phosphate is considered to be the amount of phosphate available to the plant and is the amount guaranteed on the fertilizer label.
In acidic soil, phosphorus reacts with iron and aluminum and makes it unavailable to plants.
Soil with inherent pH values between 6 - 7.5 is ideal for the availability of P₂O₅. Whereas pH values below 5.5 and between 7.5 - 8.5 limit phosphorus availability.

The major form of boron absorbed by plants is H₃BO₃ (boric acid).
Boron is an essential plant nutrient required by plants for its proper growth and functioning. It plays an important role in regulating plants' hormone levels and promoting proper growth. It increases flower production and retention, pollen tube elongation and germination, and seed and fruit development.

CAN is calcium ammonium nitrate, also known as nitro-limestone or nitrochalk. It is a widely used inorganic fertilizer, accounting for 4% of all nitrogen fertilizers used.
It is hygroscopic, and its dissolution in water is endothermic. It accounts for roughly 8% calcium and 21 - 27 % nitrogen. It is preferred for use on acidic soils. it is mainly useful as a Top dressing for fertilizer application.