Soil Science - Study Mode

[#286] Readily available water in constant matric suction is more in
Correct Answer

(A) Sandy soil

Explanation

Solution: Readily available water in constant matric suction is more in sandy soil. Matric suction or negative matric potential is the free energy change in a unit volume of water when isothermally transferred from the soil water state to the free water state. Readily available water is the water that a plant can easily extract from the soil and its value is more when Matric suction is constant in the case of sandy soil as it cannot hold and absorb much water like other soils.

[#287] Calcium hydroxide has a neutralizing value (calcium carbonate equivalent) of . . . . . . . .
Correct Answer

(B) 136%

Explanation

Solution: The neutralizing value is a measure of the amount of acid a given weight of liming material will neutralize. Calcium carbonate is used as the reference and assigned a neutralizing value of 100 percent. Calcium hydroxide has a neutralizing value (calcium carbonate equivalent) of 136%.

[#288] N content in Humic & Fulvic acids are
Correct Answer

(A) 1 - 4%

Explanation

Solution: Humic acids are the organic substances that coagulate when the strong-base extract is acidified. It is a chemical produced by decaying plants. It is used as medicine for stimulating the immune system and treating the flu, avian flu and other viral infections. A fulvic acid is a group of chemicals formed when plants and animals break down. It is found in the humus part of soil and peat. Nitrogen content in Humic & fulvic acids is 1 - 4%. Humic acid contains more carbon and less hydrogen than does the animal and plant residues from which it has formed through extensive biological decomposition.

[#289] Which country has largest deposits of K?
Correct Answer

(C) Canada

Explanation

Solution: Potash is produced worldwide in amounts exceeding 90 million tonnes per year, with Canada being the largest producer of potash, mostly for fertilizer use followed by Russia and Belarus. The most significant reserve of Canada’s potash is located in the province of Saskatchewan and is mined by the Mosaic Company.

[#290] The critical value for K deficiency in maize is
Correct Answer

(D) 1.0%

Explanation

Solution: Potassium deficiency symptoms in corn appear first on the lower leaves because potassium is easily moved within the plant from older to younger leaves. Leaf symptoms are yellowing to necrosis of the outer leaf margins. The critical value for K deficiency in maize is 1.0%. Potassium deficiency symptoms were observed when the tissue content was 2 - 3% of K and exchangeable K was less than 5 meq K/100g.