Download App

Improvement in Food Resources — Science STD 9 — Question

Rajasthan BoardEnglish MediumSTD 9ScienceImprovement in Food Resources3 Marks
Question
Write down disadvantages of crop rotation.
✓

Answer

Disadvantages of crop rotation: Crops of the same family should not be repeatedly grown in the same field. This practice will promote build up of diseases and insect pests and decrease the similar nutrients from the soil.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Que-Ans (Each of 3 Mark )" from Improvement in Food Resources→Improvement in Food Resources — all question types→Science STD 9 question papers→Rajasthan Board STD 9 question papers→Rajasthan Board question paper generator→

Similar questions

Explain the following giving examples.
Colloid.
→
What is neuron? Define it?
→
Which object is vibrating when the following sounds are produced?
  1. The sound of a sitar.
  2. The sound of table.
  3. The sound of a tuning fork.
  4. The buzzing of a bee or mosquito.
  5. The sound of a flute.
→
Explain why, osmosis can be considered to be a special kind of diffusion. Classify the following into (i) osmosis, and (ii) diffusion:
  1. Swelling up of a raisin on keeping in water.
  2. Spreading of virus on sneezing.
  3. Earthworm dying on coming in contact with common salt.
  4. Shrinking of grapes kept in thick sugar syrup.
  5. Preserving of pickles in salt.
  6. Spreading of smell of cake being baked in the kitchen.
  7. Aquatic animals using oxygen dissolved in water during respiration.
→
Show diagramatically the electron distributions in a sodium atom and a sodium ion and also give their atomic number.
→
State three reasons why you think air is a mixture and water is a compound.
→
Three different atoms of oxygen are represented as:$^{16}_{\ 8}\text{O},\ ^{17}_{\ 8}\text{O}\text{ and }^{18}_{\ 8}\text{O}$
  1. What do the subscripts $($lower figures$)$ and superscripts $($upper figures$)$ represent?
  2. What factor is responsible for the change in the superscripts $16, 17$ and $18,$ though the element is the same$?$
  3. What is the usual name for such atoms of an element?
  4. Give the nuclear composition of $​​^{18}_{\ 8}\text{O}$
→
Describe a method for separating a mixture of iron filings and sulphur powder other than that by using a magnet.
→
What is genetic manipulation? How is it useful in agricultural practices?
→
Why does the temperature of a substance remain constant during its melting point or boiling point?
→