Soil Science - Study Mode

[#471] How much farmyard manure is required for obtaining 60 kg nitrogen for a crop?
Correct Answer

(B) 120 tonnes

Explanation

Solution: FYM (farmyard manure) is an important organic resource for agricultural production in livestock-based farming systems in the semi-arid tropics of India. The chemical composition of FYM is nitrogen is 0.5% nitrogen, 0.2% phosphate. 0.5% potassium and 76% of water. For 60 kg of nitrogen for a crop, 120 tonnes of farmyard manure is required as 1 ton of FYM contains 0.5 kg of Nitrogen.

[#472] Lignins mainly decomposed by
Correct Answer

(D) Fungi

Explanation

Solution: Lignin is one of the main components of the plant cell wall and it is a natural phenolic polymer with high molecular weight, complex composition and structure. Lignin is found in the middle lamella, as well as in the secondary cell wall of xylem vessels and the fibres that strengthen plants. Fungi especially white rot fungi can decompose lignin. Although lignin is resistant to most microorganisms.

[#473] The concept of pH is suggested by the scientist
Correct Answer

(A) Sorenson

Explanation

Solution: The concept of pH is first introduced by the Danish Scientist Soren Peder Lauritz Sorensen, in 1909. He describes the way of measuring pH using potential differences, as it represents the negative power of 10 in the concentration of hydrogen ions. pH denotes "potential of hydrogen" which is a scale used to specify the acidity or basicity of an aqueous solution.

[#474] The space between fertiliser stacks and walls for should be about
Correct Answer

(C) 0.75 m

Explanation

Solution: The space between fertilizer stacks and walls should be about 0.75 m. Storage of the fertilizers is advised to be in the shed, and place the wooden platforms on the pallets, just to avoid contact between the fertilizer sacks and the ground. The stacks should not exceed 20 bags to avoid shrinking the bags at the bottom. Leave space of about 60 cm between the stacks.

[#475] Match the following columns: Column I (Fertilisers) Column II (N Content %) a. CAN 1. 82 b. Anhydrous ammonia 2. 25 c. Urea 3. 33 d. Ammonium nitrate 4. 46
Correct Answer

(B) a-2, b-1, c-4, d-3

Explanation

Solution: CAN is calcium ammonium nitrate, also known as nitro-limestone or nitrochalk, is a widely used inorganic fertilizer. It contains about 25% of nitrogen. Anhydrous ammonia is an efficient and widely used source of nitrogen fertilizer and its nitrogen content is 82%. Urea is the most important nitrogenous fertilizer in the country because of its high N content and it is 46%. Ammonium nitrate is a commonly used nitrogenous fertilizer and its nitrogen content is 33%.