Soil Science - Study Mode

[#276] Morpho-genetic system of soil classification is given by
Correct Answer

(B) Marbut

Explanation

Solution: The Morpho-genetic system of soil classification is given by Marbut in 1935 . it was further revised and elaborated by Baldwin, Kellogg, and Thorp in 1938. Marbut classified soil based on zonality, properties, and morphology emphasizing the need for examination of actual soils for the characteristics like soil colour, texture, structure, consistency, drainage conditions, etc.

[#277] Glass electrode can be used for the estimation soil pH range of
Correct Answer

(A) 1.0 - 9.0

Explanation

Solution: Glass electrode can be used for the estimation of soil pH range of 1.0 - 9.0. A glass electrode is a type of ion-selective electrode made of a doped glass membrane that is sensitive to a specific ion. It is commonly used to measure pH. Glass electrode with a glass membrane special, chemically pure, soft glass paired with a calomel reference electrode for estimation of soil pH.

[#278] Preparation of FYM by Trench Method is given by
Correct Answer

(A) C. N. Acharya

Explanation

Solution: FYM is farm yard manure, which is an important organic resource for agricultural production, including compost, cow dung, green manure, etc. Preparation of FYM (Farmyard manure) by Trench method is given by C. N. Acharya . In this method trenches of 6 - 8 m in length, 1.5 - 2 m in width, and 1 - 1.25 m in depth are prepared. A mixture of dung and urine-soaked litter is deposited in layers in these trenches until it becomes 50 cm above the ground layer. It is then watered carefully and mud plastered. The FYM is ready in about 6 months.

[#279] Acid rocks have . . . . . . . . silica.
Correct Answer

(C) 65 - 70%

Explanation

Solution: Acid rocks refer to the chemical composition of igneous rocks that has a large percentage of silica content. Acid rocks have 65 - 70 % of silica and usually contain more than 20% of free quartz. Typical acid rocks are granite and rhyolite.

[#280] Which biological organism having highest influence on soil aggregate formation?
Correct Answer

(C) Plant roots

Explanation

Solution: Plant's roots are biological organisms having the highest influence on soil aggregate formation. Plant roots play a vital role in aggregate formation by secreting organic compounds called root exudates. These helps bind soil together near the root zone. However, Soil aggregates are clumps of soil particles that are held together by moist clay, organic matter (like roots), gums (from bacteria and fungi) and fungal hyphae.