Soil Science MCQ Question and Answer | Agriculture MCQ Question

The micronutrient needed in the smallest amount by the plant is Molybdenum.
Molybdenum is an essential component in two enzymes that convert nitrate into nitrite and then into ammonia before it is used to synthesize amino acids within the plant. It is also required by symbiotic nitrogen fixing bacteria in legumes to fix atmospheric nitrogen.
The normal range for most plant tissue is between 0.3 - 1.5 ppm.

Amphibole is a primary mineral having huge importance in terms of plant nutrition.
It is a group of inosilicate minerals, form prism or needle-like crystals. Amphiboles are the primary constituent of amphibolites. It is a major group of hydrous minerals that occurs in a wide range of rock types.

X-ray diffraction analysis is based on Bragg’s law, which states that "when the X-ray is incident onto a crystal surface, its angle of incidence θ, will reflect with the same angle of scattering θ.
It encompasses the superposition of wavefronts scattered by lattice planes, leading to a strict relation between wavelength and scattering angle, or else to the wave vector transfer concerning the crystal lattice.

Humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a soil organic matter rich in nutrients and retains moisture in the soil.
The carbon and nitrogen ratio of humus is about 10 : 1. The carbon to nitrogen ratio is significant in composting because microorganisms need a good balance of carbon and nitrogen to remain active.

The youngest fully mature leaves of the main stem are used for tissue tests in the cotton plant because these are the growing cells and show the accurate status of nutrients in the plant.
Tissue analysis shows if the crop is taking up the nutrients from the soil or through the tissue from a foliar application.

Fungi is the group of microorganisms that have the highest biomass in the soil.
The maximum limit is up to 790 μg C/g soil and it is found in the soil with surface organic horizons in the form of thin moss/lichen litters, in which the development of fungal mycelium is most active.

Udolls is the suborder of Mollisols in soil taxonomy. They are divided into eight suborders: Albolls, Aquolls, Rendolls, Gelolls, Cryolls, Xerolls, Ustolls and Udolls.
Mollisols are the soils of grassland ecosystems or cropland. They are characterized by a thick, dark surface horizon. Mollisols are among some of the most important and productive soils in the world.

SSP is the most popular phosphatic fertilizer after DAP as it contains 3 major plant nutrients i.e. Phosphorus, Sulphur and Calcium along with traces of other micronutrients.
SSP is a grey to brownish coloured material containing monocalcium phosphate and calcium in almost equal proportions. It is the least hygroscopic but needs moisture-proof packing to avoid lump formation during storage.

The honeycomb structure is found in Phyllosilicate, also termed sheet silicates. The basic structure of the phyllosilicates is based on interconnected six-member rings of SiO₄^-4 tetrahedra that extend outward in infinite sheets. Three out of the 4 oxygens from each tetrahedral are shared with other tetrahedra.

Lateralization is the process of the accumulation of iron and aluminium oxides in the soil.
It is also termed tropical weathering and is a prolonged process of chemical weathering that produces a wide variety in the thickness, grade, chemistry, and ore mineralogy of the resulting soils.
Typical laterite is porous and claylike. It contains the iron oxides minerals goethite, HFeO₂; lepidocrocite, FeO(OH); and hematite, Fe₂O₃. It also contains titanium oxides and hydrated oxides of aluminum, the most common and abundant of which is gibbsite, Al₂O₃ · 3H₂O.