Soil Science - Study Mode

[#921] Hill soils are generally
Correct Answer

(A) Acidic

Explanation

Solution: Soils developed in hilly areas are susceptible to erosion. The agricultural potential of hill soils is mainly low for field crops, but it ranges between low and high for tree crops. Nutrients especially nitrogen are lost from the soils with runoff water. Hill soils are generally acidic, which means their pH ranges from less than 5.5 for most of the year.

[#922] Ammonium nitrate contains
Correct Answer

(C) 33 - 35% N

Explanation

Solution: Ammonium nitrate is a salt of ammonia and nitric acid with chemical formula, (NH 4 NO 3 ). It is widely used in fertilizers and explosives. The commercial-grade of ammonium nitrate contains 33 - 35% of Nitrogen. It is a greyish white solid in the form of prills and is soluble in water. It produces toxic oxides of nitrogen during combustion.

[#923] Rhizobium of alfalfa group is
Correct Answer

(D) Melilolti

Explanation

Solution: Rhizobium is a genus of gram-negative soil bacteria that fix nitrogen for plants. Alfa alfa is an important leguminous forage crop, which is hypothesized to select compatible rhizobial partners from the rhizosphere to form nitrogen-fixing nodules. Rhizobium of alfalfa group is Melilolti . Meliloti are motile and possess a cluster of peritrichous flagella. It fixes atmospheric nitrogen into ammonia for their legume symbionts.

[#924] Cereal straw is a particularly rich source of
Correct Answer

(B) Potash

Explanation

Solution: Straw is an agricultural byproduct consisting of dry stalks of cereal plants after the grain and chaff have been removed. It has several different uses, including fuel, livestock bedding, fodder, thatching and basket making. Straw may be fed as part of the roughage component of the diet to cattle or horses. It has a low digestible energy and nutrient content. It is a particularly rich source of Potash.

[#925] According to heat conductivity
Correct Answer

(A) Sand > Loam > Clay > Peat

Explanation

Solution: The soil thermal conductivity is the ratio of the magnitude of the conductive heat flux through the soil to the magnitude of the temperature gradient. According to heat conductivity soils can be classified as : Sand > Loam > Clay > Peat. The soil thermal conductivity of sandy soil is maximum and the lowest is for Peat soil.