Soil Science MCQ Question and Answer | Agriculture MCQ Question

In plants, deficiency of Zn is usually associated with concentrations of less than 20 ppm. Zinc is a micronutrient element which means it is required in the least proportions by plants for their proper functioning.
Deficiencies of Zn are observed with concentrations of less than 20 ppm. Its normal range is 25 - 150 ppm in plants. However, toxicities will occur when the Zn leaf concentration exceeds 400 ppm.

The Bar is widely used in many countries as a unit of pressure.
The bar is equal to 0.9869 atm. A standard atmosphere is abbreviated atm, also a unit of pressure equal to the average atmospheric pressure at sea level.
The bar is equal to the weight of a 1020 cm water column. Inches of the water column is a measurement unit for measuring static pressure.
The bar is equal to a 75.01 cm high mercury column. A milimetre of mercury is a manometric unit of pressure, it is defined as the extra pressure generated by a column of mercury one millimeter high. It is denoted as mmHg.

36.5 grams of hydrochloric acid is a 1 N (one Normal) solution of HCl. A normal is one gram equivalent of a solute per litre of solution. The strength of laboratory HCl is 11 N.
In the context of acid and bases, it is generally assumed that N refers to the proton or the hydroxide ion released in water when acid is dissolved.

The salt index is the ratio of the increase in osmotic pressure produced by the fertilizer to that produced by the same weight of sodium nitrate.
It is calculated by comparing the increase in osmotic potential brought about by the addition of that fertilizer material compared to the increase in osmotic potential when an equivalent weight of sodium nitrate is added to water.

Near the canal banks, the soil becomes alkaline. These are largely predominant in the Indo-Gangetic plains encompassing most of the states of our country.
Alkaline soils are rich in high amounts of calcium, sodium and magnesium. They are rich in high pH value. It has a poor soil structure and low infiltration capacity.

Gypsum is a soft sulphate mineral composed of calcium sulphate dehydrate. It is used as fertilizer and helps soil better absorb water and reduces erosion also helps in the reclamation of soil.
The gypsum requirement (GR) is the calculated amount of gypsum necessary to add to reclaim the soil.

$${\text{GR}} = \frac{{{\text{ES}}{{\text{P}}_{\left( {{\text{initial}}} \right)}} - {\text{ES}}{{\text{P}}_{\left( {{\text{final}}} \right)}}}}{{100}} \times {\text{CEC}}$$

ESP is Exchangeable sodium percentage.
CEC is Cation exchange capacity.

The dominant spectral colour in soil indicates Hue.
Hue is the dominant spectral colour and is related to the dominant wavelength of light. It indicates it's related to red, yellow, green, etc.
Hue is determined by the dominant wavelength of the visible spectrum. It is an attribute that permits colours to be classified as red, yellow, blue or an immediate colour.

Complex fertilizers contain more than one major nutrient in a Combined form.
Complex fertilizers contain two or three primary plant nutrients of which two primary nutrients are in chemical combination. These fertilizers are usually produced in granular form. They are made by mixing basic fertilizers derived from ammonia with salts containing phosphorus or potassium.

Allophane, Imogolite are Volcanic in origin. Volcanic soils are formed by weathering of Volcanogenic materials.
Allophane is an important colloidal component of soils derived from recently deposited volcanic materials. Imogolite is an aluminium silicate clay mineral formed from volcanic ash.

Eusebe Gris established the essentiality of Iron (Fe) for the plant in 1844.
He showed that certain chlorosis in plants could be reserved by treating roots and leaves with an iron solution.
Iron is a micronutrient required in the least amount but essential for the proper functioning of photosynthesis and chlorophyll synthesis in plants.