Soil Science - Study Mode

[#476] Match the following columns: Column I (Bacteria) Column II (Functions) a. Nitrobacter 1. Fixation of atmospheric nitrogen b. Ammonifying bacteria 2. Formation of NH 4 + nitrogen c. Denitrifying bacteria 3. Formation of NO 3 - d. Rhizobium sp. 4. Formation of N 2
Correct Answer

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

Explanation

Solution: Nitrobacteria are obligate aerobes. It plays an important role in the nitrogen cycle by oxidizing nitrite (NO 3 - ) into nitrate and ultimately nitrogen in the soil. Ammonifying bacteria convert ammonia into atmospheric nitrogen. Denitrifying bacteria results in the conversion of nitrates in the soil to free atmospheric nitrogen. Rhizobium species are a group of bacteria that helps in fixing atmospheric nitrogen in plants.

[#477] In crop logging, during growing season, plant tissue is sampled every . . . . . . . . days and analysed for N, sugar, moisture and weight of the young sheath tissue
Correct Answer

(C) 35

Explanation

Solution: In crop logging, during the growing season, plant tissue is sampled every 35 days and analyzed for Nitrogen, sugar, moisture and weight of the young sheath tissue. Crop logging is a system of monitoring the nutritional status of plants by periodic and regular sampling and analysis of soil and plant parts. The main motive is to be able to correct the nutritional problem while the plant is still standing and can benefit from the corrective measure.

[#478] Terai soil comes under which soil order?
Correct Answer

(B) Mollisol

Explanation

Solution: Terai soil comes under Mollisol . Terai is a low land in a lowland region in northern India Soils which are mostly similar to mollisols but contain either continuous or discontinuous permafrost. Mollisol is a soil type that has deep, high organic matter, nutrient-enriched surface soil, typically between 60 and 80 cm in depth, and this fertile surface horizon is called mollic epipedon.

[#479] If one kg nutrient worth Rs. 6 produces extra crop worth Rs. 20, the Value Cost Ratio (VCR) is
Correct Answer

(C) 14

Explanation

Solution: Then Value Cost Ratio (VCR) is the amount of money earned per money spent. In response to the fertilizer, the ratio of unit fertilizer price to unit crop price for different levels of fertilizer response. If one kg nutrient worth Rs. 6 produces an extra crop worth Rs. 20, the value cost ratio will be 20 - 6 = 14.

[#480] Five stages of soil development is given by
Correct Answer

(D) Both B and C

Explanation

Solution: Five stages of soil development are given by both Mohr and Van Baren . They hypothesize five stages of soil development in the tropics based on the properties of soil, and these are initial, juvenile, virile, senile and final . The evolution of soils and their properties is called soil formation, and the factors which influence this are parent material, topography, climate, organisms and time.