Explain how soil gets affected by the continuous plantation of crops in a field.
Solution and Explanation
Soil supplies mineral nutrients to the crop. These nutrients are essential for the growth of plants. Continuous growing of crops in the same field makes the soil poorer in certain nutrients. This makes the soil infertile. And then, to replenish the soil with nutrients farmers need to add manures to the soil.
Questions Asked in CBSE Class VIII exam
- Subtract 4p2q – 3pq + 5pq2 – 8p + 7q – 10 from 18 – 3p – 11q + 5pq – 2pq2 + 5p2q
- CBSE Class VIII
- Addition and Subtraction of Algebraic Expressions
- Differentiate between regular and diffused reflection. Does diffused reflection mean the failure of the laws of reflection?
- CBSE Class VIII
- Regular and Diffused Reflection
Fill in the blanks in the sentences below (the verbs given in brackets will give you a clue).
(i) The earth trembled, but not many people felt the ____. (tremble)
(ii) When the zoo was flooded, there was a lot of _____ and many animals escaped into the countryside. (confuse)
(iii) We heard with _____ that the lion had been recaptured. (relieve)
(iv) The zookeeper was stuck in a tree and his _____ was filmed by the TV crew. (rescue)
(v) There was much _____ in the village when the snake charmer came visiting. (excite)
- CBSE Class VIII
- The Tsunami
- Fill in the blanks with suitable words.
- Time taken by an object to complete one oscillation is called ___ .
- Loudness is determined by the ___ of vibration.
- The unit of frequency is ___.
- Unwanted sound is called __________ .
- Shrillness of a sound is determined by the ___ of vibration.
- CBSE Class VIII
- Sound Produced by Humans
- Add the following. l2 + m2, m2 + n2, n2 + l2, 2lm + 2mn + 2nl
- CBSE Class VIII
- Addition and Subtraction of Algebraic Expressions