Soil Science - Study Mode
[#911] Two nutrients needed by plants in largest amounts are N and
Correct Answer
(A) Potassium
Explanation
Solution: Out of 17 essential nutrients of plants, some are macronutrients i.e. required in large amounts by plants whereas micronutrients are required in very fewer amounts. Nitrogen, phosphorus and Potassium are the primary nutrients (Macronutrients) required by plants in higher quantities than other elements and without which the plants may not survive and grow. These nutrients boost the plant enzyme function, improve biochemical processes and help in plant cell growth.
[#912] Soils below the critical level of available nutrient are expected to
Correct Answer
(C) Respond to fertiliser
Explanation
Solution: Soils below the critical level of available nutrients are expected to respond to fertilizer. The nutrient concentration in the plant below which a yield response to added nutrient occurs. Critical levels or ranges vary among plants and nutrients but occur somewhere in the transition between nutrient deficiency and sufficiency.
[#913] A straight fertiliser is one which
Correct Answer
(B) Has one major nutrient
Explanation
Solution: A straight fertilizer has one major nutrient. Straight fertilizers are those which supply only one primary plant nutrient, namely nitrogen or phosphorus or potassium. Depending upon the nutrient availability they are further classified as nitrogenous, phosphatic and potassic fertilizers.
[#914] Non-essential mineral nutrients (elements) are required by
Correct Answer
(B) Certain plants, but not all, to perform their metabolic activities
Explanation
Solution: Non-essential mineral nutrients (elements) are required by certain plants, but not all, to perform their metabolic activities. The non-essential plant elements include hydrogen, oxygen and carbon. Essential nutrients are those that cannot be synthesized by the human body, hence they need to be absorbed from outside whereas, non-essential nutrients are those that can be synthesized by internal processes.
[#915] Example of neutral igneous rock is
Correct Answer
(D) All of the above
Explanation
Solution: Igneous rock is formed through the cooling and solidification of magma or lava. These rocks occur in a wide range of geological settings, shields, platforms, orogens, basins, large igneous provinces, extended crust and metallic crust. Syenite, Trachite and Andesite are examples of igneous rock.