Soil Science MCQ Question and Answer | Agriculture MCQ Question

Low temperature and high rainfall are conducive for the accumulation of OM.

Typhoons are tropical storms with wind speeds of at least 74 miles (119 kilometers) per hour just like a hurricane.
Typhoon derives their energy from Latent heat of vaporization of water from the ocean surface, which ultimately condenses into clouds and rain when moist air rises and cools to saturation. Thus the main source of energy for typhoons is the Ocean both by direct heat transfer from their surface and by the evaporation of water.

Out of the given options of pesticides, Dieldrin is the most toxic insecticide and is now banned also due to concerns about their impact on human health. It increases the threat of breast cancer.
Dieldrin was widely used as a pesticide for corn, cotton and citrus crops. It persists in the soil with a half-life of five years at temperate latitudes.

Blossom end rot of tomato is a physiological disease and is caused by the deficiency of Calcium in the plant. It can occur in both green and ripe fruits and is identified by water-soaked areas that gradually widen and mature into sunken, brown, leathery spots on the bottom end.
This disease can be eradicated by adding high levels of calcium like bone meal, oyster shell or gypsum.

Rock phosphate is also known as Phosphorite and is a non- detrital sedimentary rock that contains high amounts of phosphate minerals. The phosphate content of phosphorite varies between 20% - 30% of phosphorus pentaoxide (P₂O₅).
Rock phosphate contains high amounts of phosphorus and calcium.

Coordination number is also known as ligancy, of a central atom in a molecule or crystal refers to the total number of atoms, ions or molecules bonded to the atom.
The ion/molecule/atom surrounding the central ion/molecule/atom is called a ligand. For molecules and polyatomic ions, the coordination number is determined by simply counting the other atoms to which it is bonded.
The coordination no. of potassium is 12.

Following are the indices used to quantify the effect of climate on soil formation:
Thornwaite’s PE index developed a T/E index to represent thermal efficiency,
Precipitation- Climate affects the formation of soil indirectly, high temperatures and rainfall increase the degree of weathering and therefore the extent of soil development.
NSQ ( Niederschlag-sattigungsdefizit Quotient) is the humidity factor and is the total annual precipitation (mm) divided by the absolute saturation deficit of air.

Plasticity Index is given by Atterberg which is expressed in percent of the dry weight of the soil sample. It refers to the size of the range of the moisture content at which the soil remains plastic and it usually depends on the amount of clay present in the soil.
The plasticity index is calculated as the numerical difference between the liquid limit (LL) and plastic limit (PL), PI = LL - PL

Urea of foliar spray should not contain biuret more than 0.25% for citrus fruits. Fertilizer-grade urea contains the impurity Biuret which is toxic to the plant, especially when applied as a leaf dressing. Thus Biuret more than the advised percentage for specific plants can damage the root of the plant and also useful bacteria and chock the capillary of the root cell, Nitrogen carrying capacity will be reduced.

Fe is an important component of all the given enzymes that are nitrogenase, nitrate reductase, and nitrite reductase. All these are enzymes responsible for nitrogen fixation.
Iron is an essential cofactor for a variety of redox reactions in plant metabolism and Fe requires enzymes to catalyze reactions that also involve oxygen, as a reagent or product of the reaction itself or as an entry or end point a metabolic pathway.