Soil Science MCQ Question and Answer | Agriculture MCQ Question

Anhydrous Ammonia is an efficient and widely used source of nitrogen fertilizer. It contains 82% of Nitrogen in the ammoniacal form that is easily absorbed by the plants.
Anhydrous as the word refers to 'without water', that means the form of ammonia that is without water.

Porosity is the measure of empty spaces in the soil. The porosity of the surface soil usually decreases as the size of the particle increases. The porosity of subsoil is lower than the surface soil due to compaction by gravity.
It can be measured by the formulae:
$${\bf{P = 100 - }}\left( {\frac{{{\bf{Bulk}}\,{\bf{Density}}}}{{{\bf{Particle}}\,{\bf{Density}}}}} \right){\bf{ \times 100}}$$

The first law of Restitution is given by Liebig, which states 'always restore the nutrients removed by the farming process, so as not to reduce soil fertility.
The Law of minimum is also given by Liebig which states that farm yields are proportional to the minimum amount of any single fertilizer element present, relative to the Plant's need.

Fertilization Consumption in India went up by 2.95% from 170 kilogram per hectare to 175 kilogram per hectare. India consumes about 25.6 million tonnes of fertilizers and mostly nitrogen followed by Phosphorous and potassium.
India ranks third in the consumption of fertilizer in the world. China is the world’s largest consumer of fertilizers.

CAN is the Calcium Ammonium Nitrate, also known as Kisan Khad. It contains around 8% calcium and 25% - 28% of Nitrogen. Mostly preferred for use on acidic soil, as the calcium present in it prevents the development of acidity in the soil.

NPK complex is a solid three nutrient fertilizer in a single granule that is produced via chemical or physical processes but excluding bulk blends. And normal NPK is a complex fertilizer that contains all three major nutrients 10% Nitrogen, 26% Phosphorous and 26% Potash.
As both are the same, thus, NPK complex can be used if NPK dose is required.

Bulk density is an indicator of soil compaction. It is calculated as the dry weight of soil divided by its volume. It is expressed in grams per cubic centimeter.
Portion density = 2.65 g/cc
Pore space = 40%
Putting on the formula.
$$\eqalign{ & {\text{Pore space }}\% = 100 - \left( {\frac{{{\text{bulk density}}}}{{{\text{portion density}}}}} \right) \times 100 \cr & 40 = 100 - \left( {\frac{{{\text{B}}{\text{.D}}}}{{2.65}}} \right) \times 100 \cr} $$
Solving this,
Bulk density = 1.59 g/cc

Mull humus is the humus with a granular layer known as mull, which is a porous mixture of organic material and mineral soil.
Mull humus is characteristic of hardwood forests, deciduous forests or grasslands in warm and humid climates.
Mull humus is specifically associated with Earth worm.

Sodic soil means the soil is rich in sodium ions, sodium salts are leached through the soil and some sodium remains bound to clay particles and illite is the group of closely related non-expanding clay minerals.
2, 4-D is the Herbicide that controls broadleaf weeds.
Ethylene in gaseous form is used to initiate the ripening process in the fruits, which can be referred to as artificial ripening.
N and -serve is a nitrogen stabilizer and it inhibits nitrification, which helps to optimize the yield and profit potential of corn and wheat.

Soil aggregation can be estimated by using Yoder’s apparatus.
Yoder's apparatus is a wet sieve shaker Machine specially designed for the estimation of soil strength and soil permeability with the help of ASTM stainless steel sieves.