Soil Science MCQ Question and Answer | Agriculture MCQ Question

Volcanic soils also known as Andisols, are formed from volcanic ash and cinder deposits. Andisols are soils formed in volcanic ash and defined as soils containing high proportions of glass and amorphous colloidal materials, including allophane, imogolite and ferrihydrite.
They are generally quite young and typically very fertile.

Soil materials deposited by glaciers are known as Moraine and Till.
A moraine is a material left behind by a moving glacier. This material is usually soil and rock. Rivers carry along all sorts of debris and silt that eventually builds up to form deltas, glaciers transport all sorts of dirt and boulders that build up to form moraines.
Till is derived from the erosion and entrainment of material by the moving ice of a glacier. It is deposited some distance down-ice to form terminal, lateral, medial and ground moraines.

The pH of soil solutions determines active acidity. However, soil pH is a measure of the concentration of hydrogen ions in the soil solution.
Whereas active acidity is the number of hydrogen ions that are available in the soil water solutions undergoing pH tests.

Single super phosphate (SSP) is produced by reacting rock phosphate with sulphuric acid (H₂SO₄). The chemical formula of SSP is Ca(H₂PO₄)₂ · 2H₂O (Monocalcium Phosphate Dihydrate). In SSP, the phosphorus is in the form of P₂O₅ and contains 16% P₂O₅.
SSP is the most popular phosphatic fertilizer after DAP containing 3 major plant nutrients namely phosphorus, Sulphur and Calcium along with many micronutrients.

Fe concentration used for the foliar spray is 0.4%.
The application of foliar sprays is a common means of correcting Fe deficiency in crops. Applying chelated iron to the soil is the most effective way of correcting yellow leaves as it requires just a single application.
Foliar spray is used when rapid response is needed to correct a chlorotic condition. A foliar spray with iron sulphate or iron chelate solution may be applied when the tree is in full leaf.

Ammonium Sulphate is an inorganic salt and a single-type fertilizer with several commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen and 24% Sulphur.
The primary use of ammonium is as a fertilizer for alkaline soils. In the soil the ammonium ion is released and forms a small amount of acid, lowering the pH balance of the soil, while contributing essential nitrogen for plant growth.

In submerged soil, the availability of phosphorus increases.
On submergence, the availability of native as well as applied phosphorus increases in the soil. The phosphorus transformation is also known to be associated with pH changes in submerged soils.
Soil available P is the fraction of total P in soil that is readily available for absorption by plant roots.

Nitrogen is the plant element that accounts for at least one-half of the total number of ions absorbed. Nitrogen is absorbed by plants in the form of nitrate, and ammonium ions. And the other ions absorbed by plants are phosphate and potassium ions.

Potassium sulphate has a chemical composition of K₂SO₄., and its molecular weight is 174.26. A water-soluble fertilizer with high potassium and sulphate content along with an optimal amount of sodium.
It helps in protein synthesis and enzyme function requirements. This combination of potassium and Sulphur ensures strong flower and fruit development.