Soil Science - Study Mode
[#536] Town compost contains merely
Correct Answer
(A) 1.4% N and 1.0% P 2 O 5
Explanation
Solution: The compost made from the town refuses like night soil, street sweepings and dustbin refuses is called town compost . It contains 1.4% Nitrogen and 1% P 2 O 5 . It is used to fertilize and improve the soil by recycling organic materials.
[#537] Which one of the following pair is mismatched
Correct Answer
(D) Law of limiting factor : Lundegardh
Explanation
Solution: L-value was first suggested by Larsen in 1952. L-value also known as ‘Labile form’ is the amount of phosphorus in the soil and in the soil solution which is exchangeable with added orthophosphate to the soil as measured by a plant growing in the system. Colwell in 1967 emphasized the importance of soil testing through an integrated soil test approach to crop yield response to provide information on fertilizer requirements. Desai and Biswas in India first demonstrated the production of combustible gas from cow dung i.e. Biogas by anaerobic fermentation in 1975. The Law of limiting factors is given by Blackmann, not Lundegardh.
[#538] For Organic colloids & Fe / Al hydrous oxides
Correct Answer
(C) ZPC = isoelectric point
Explanation
Solution: The organic colloids consist of convoluted chains and rings of carbon atoms bonded to hydrogen, oxygen and nitrogen. For organic colloids and Fe / Al hydrous oxides, ZPC = isoelectric point. ZPC is the point of zero charges and is described as the pH at which the net charge of the total particle surface is equal to zero. And the isoelectric charge is the pH at which a particular molecule carries no net electrical charge.
[#539] Most salt tolerant grass is
Correct Answer
(A) Kamal grass (Diplachne fusca)
Explanation
Solution: Most salt tolerant grass is Kamal Grass (Diplachne fusca). It is widespread species of grass in the genus Diplachne, native to North America, Africa, Asia, etc. all other places. It prefers to live in salty, wet conditions, such as in salt marshes and shallow depressions.
[#540] The soil erodibility factor (K) indicates the inherent erodibility of a soil gives an indication of the soil loss from a unit plot . . . . . . . . m long with a 9% slope under continuous fallow culture
Correct Answer
(A) 22
Explanation
Solution: The soil erodibility factor (K) indicates the inherent erodibility of soil indicates the soil loss from a unit plot 22 m long with a 9% slope under continuous fallow culture. K factor represents both susceptibility of soil to erosion and the rate of runoff as measured under the standard unit plot condition.