Soil Science - Study Mode

[#381] Fertilisers SSP dissolve in soil to furnish phosphate, calcium and
Correct Answer

(C) Sulphur

Explanation

Solution: Superphosphate is a component fertilizer that primarily consists of monocalcium phosphate, Ca(H 2 PO 4 ) 2 . SSP is the most popular phosphatic fertilizer after DAP as it contains 3 major plant nutrients namely Phosphorus, Sulphur and Calcium along with traces of many micro-nutrients. Fertilizers SSP dissolve in the soil to furnish Phosphate, Calcium and Sulphur .

[#382] Critical limit of available phosphorus in soil for wheat crop by Olsen's method is
Correct Answer

(B) 10 kg/ha

Explanation

Solution: The critical limit of available phosphorus in soil for the wheat crop by Olsen's method is 10 kg/ha. Olsen’s method is done for the estimation of phosphorus and is based on the extraction of phosphate from the soil by 0.5 N sodium bicarbonate solution adjusted to pH 8.5. this procedure is suitable for calcareous, alkaline, neutral, and slightly acidic soils containing CaPO 4 .

[#383] Alluvial fan is seen in India?
Correct Answer

(A) Haridwar

Explanation

Solution: An alluvial fan is an accumulation of the sediments that fan outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. This accumulation is shaped like a section of a shallow cone, with its apex at the source of sediments. An alluvial fan is seen in India near Haridwar as it is along the Himalayas mountain front on the Indo-Gangetic plain.

[#384] Calcium cynamide contains nitrogen (%)
Correct Answer

(D) 21

Explanation

Solution: Calcium Cyanamide is the inorganic compound with the formula CaCN 2 . It is the calcium salt of the cyanamide anion. In contact with water, it decomposes and liberates ammonia. This is widely used as nitrogen fertilizer and is also known as Nitrolime. It contains about 21% nitrogen.

[#385] The major source of negative charge on humus colloids is due to
Correct Answer

(D) All of these

Explanation

Solution: Humus is the organic component of the soil. The charge on humus colloids is dependent on pH. It mostly exhibits a low negative charge. Under strongly acid conditions hydrogen is rigidly bound and not easily replaceable by other cations. The major source of negative charge on humus colloids is due to carboxylic, enolic, and phenolic groups.