Soil Science - Study Mode

[#901] Sodium adsorption ratio (SAR) can be calculated by using of formula
Correct Answer

(B) $${ ext{SAR}} = frac{{{ ext{N}}{{ ext{a}}^ + }}}{{sqrt {frac{{{ ext{C}}{{ ext{a}}^{2 + }} + { ext{M}}{{ ext{g}}^{2 + }}}}{2}} }}$$

Explanation

Solution: Sodium adsorption ratio is a measure of the amount of sodium (Na) Relative to calcium (Ca) and Magnesium (Mg) in the water extract from saturated soil paste. It is the ratio of the sodium concentration divided by the square root of one-half of the calcium and magnesium concentration. It can calculated by using formula: $${ ext{SAR}} = frac{{{ ext{N}}{{ ext{a}}^ + }}}{{{{left[ {left( {frac{{{ ext{C}}{{ ext{a}}^{2 + }} + { ext{M}}{{ ext{g}}^{2 + }}}}{2}}
ight)}
ight]}^{0.5}}}}$$

[#902] On an average 1 kg N, P 2 O 5 , K 2 O is added to increase grain yield by
Correct Answer

(C) 10 kg

Explanation

Solution: Nitrogen, phosphorus, and potassium are macronutrient uptake by crop yields and crop residues by attaining high-input potential yields compared to that low-input yields, and the number of fertilizers applied. On an average 1 kg of N, P 2 O 5 and K 2 O are added to increase grain yield by 10 kg.

[#903] Potash Feldspar releases less amount of K, because
Correct Answer

(A) Less rupture of Si-O-Al bonds

Explanation

Solution: Potassium feldspar refers to several minerals in the feldspar group containing potassium. It is observed the rate of K uptake by the plant is usually greater than the rate of K release from the weathering of feldspar it is because of less rupture of Si-O-Al bonds.

[#904] Who consider the various properties of soils in relation to plant production
Correct Answer

(B) Edaphologists

Explanation

Solution: Edaphologists are the researchers who study soil by examining a variety of factors or soil properties that govern plant (flora) and animal (fauna) life in the soil. They study various properties of soil in plant production. Edaphic factors are those soil conditions that affect the organisms living in a particular area.

[#905] The water held with a water potential greater than $$frac{1}{3}$$ bar is known as
Correct Answer

(C) Gravitation water

Explanation

Solution: The water held with a water potential greater than $$frac{1}{3}$$ bar is known as Gravitation water . Gravitational water is the water that moves through the soil by the force of gravity and drains, the water moves in the larger pores of the soil and drains quickly because there is insufficient tension to hold the water against the force of gravity.