Soil Science - Study Mode

[#646] Height of anemometer should be placed at
Correct Answer

(C) 10 m

Explanation

Solution: An anemometer is an instrument that measures wind speed and weed pressure. It is based on the principle that the air stream will cool a heated object because the cooling rate can be determined by the airflow speed. The height of the anemometer should be placed at 10 m.

[#647] Which of the following pairs is not correctly matched in the term of Organic Substances and C/N ratio?
Correct Answer

(D) Saw dust ⇔ 1000 : 1

Explanation

Solution: The carbon and nitrogen ratio of soil microorganisms is near 8 : 1. Soil microorganisms must acquire enough carbon and nitrogen from the environment in which they live to maintain that ratio in their bodies. The C/N ratio of organic matter in soil is 10 : 1 approx. The C/N ratio of rotted manure is quite higher and it is 20 : 1. Manures and legume straws will decompose in soil without net immobilization of N. The recommended proportion of C/N in sawdust is 3 : 2, not 1000 : 1. Saw dust contains 40% lignin and 60% cellulose, only 0.048% of nitrogen and traces of phosphorus, potassium and calcium.

[#648] Soil colour determination chroma refers to which of the following
Correct Answer

(C) Purity or strength of colour

Explanation

Solution: Chroma in soil colour determination refers to the relative purity or strength of the spectral colour and increases with decreasing greyness. In the soil colour chart, all colours on a given card are of a constant hue, designated by a symbol in the upper right-hand corner of the card.

[#649] Blood meal contains
Correct Answer

(C) 13 - 20% N

Explanation

Solution: A blood meal is extremely rich in Nitrogen. It contains about 13 - 20% Nitrogen, 1% phosphorous and 0.6% of potassium. It is a dry, inert powder made from blood, used as a high-nitrogen organic fertilizer, non-synthetic and high protein animal feed. A blood meal is composed of protein mostly, small amounts of fats and ash. It usually comes from cattle or hogs as a slaughterhouse by-product.

[#650] Hydraulic Conductivity does not depend on
Correct Answer

(D) No. of pores

Explanation

Solution: Hydraulic conductivity is a property of vascular plants, soils and rocks that describes the ease with which a fluid can move through pore spaces or fractures. It depends on the intrinsic permeability of the material, the degree of saturation and the density and viscosity of the fluid. It also depends on pore geometry, pore size and pore tortuosity. It does not depend on No. of pores.