Soil Science - Study Mode

[#226] Which fertilizer act as a nitrification inhibitor and as a slow release N source
Correct Answer

(D) DCD

Explanation

Solution: DCD is the fertilizer that acts as a nitrification inhibitor and as a slow-release N source. Dicyandiamide (DCD) is commonly used in fertilizer formulations as a nitrification inhibitor to slow the release of nitrogen into plant available forms that are also more prone to losses. DCD works by blocking the active site, it also slows the conversion of ammonium to nitrate preventing the loss of nitrates.

[#227] A soil, which has pH varies between 7.5 to 8.5 and ESP less than 15 and total soluble salt content is more than 0.11, the soil is called
Correct Answer

(A) Saline soil

Explanation

Solution: A soil, which has pH varies between 7.5 to 8.5 and ESP less than 15 and total soluble salt content is more than 0.11, the soil is called Saline soil. ESP is exchangeable sodium percentage and it measures the proportion of cation exchange sites occupied by sodium. Soils are considered sodic when the ESP is greater than 6 and highly sodic when greater than 15.

[#228] Which method is applied for testing of Fe, Zn, Cu and Mn
Correct Answer

(D) DTPA

Explanation

Solution: DTPA method is applied for testing of (Iron) Fe, (Zinc) Zn, (Copper) Cu and (Manganese) Mn. DTPA (diethylene triamine penta acetic acid) is a method of extraction method of micronutrients. It is a non-equilibrium extraction for estimating the potential soil availability of the above minerals. It was developed by Soltanpour and Workman.

[#229] Unit of Hydraulic gradient is
Correct Answer

(B) unit less

Explanation

Solution: The hydraulic gradient is the driving force that causes groundwater to move in the direction of maximum decreasing total head. In soil science, it describes the effectiveness of the driving force behind water movement. There is no unit of Hydraulic Gradient, it is unit less .

[#230] Which one of the following is a manganese containing minerals
Correct Answer

(C) Pyrolusite

Explanation

Solution: Pyrolusite is a manganese-containing mineral. It is a mineral consisting essentially of manganese dioxide (MnO 2 ) and is important as an ore of manganese. It is a black, amorphous appearing mineral, often with a granular, fibrous or columnar structure, sometimes forming Reni form crusts.