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

Give the functions of plasma of blood.
→
Give two examples each of:
  1. Narrow leaved rabi season weed.
  2. Broad leaved kharif season weed.
→
If the distance between masses of two objects is increased by five times, by what factor would the mass of one of them have to be changed to maintain the same gravitational force? Would there be an increase or a decrease in the same?
→
A cyclist is travelling at $15ms^{-1}.$ She applies brakes so that she does not collide with a wall $18m$ away. What deceleration must she have?
→
A man wearing a bullet$-$proof vest stands still on roller skates. The total mass is $80\ kg.$ A bullet of mass $20$ grams is fired at $400\ m/s.$ It is stopped by the vest and falls to the ground. What is then the velocity of the man?
→
Calculate the molecular masses of the following:
$a.$ Hydrogen$, H_2$
$b.$ Oxygen$, O_2$
$c.$ Chlorine$, Cl_2$
$d.$ Ammonia$, NH_3$
$e.$ Carbon dioxide$, CO_2$
$($Atomic masses $: H = 1 u; O = 16 u; Cl = 35.5 u; N = 14 u; C = 12 u)$
→
A stone is thrown vertically upward with an initial velocity of $40\ m/ s$. Taking $g = 10\ m/ s^2,$ find the maximum height reached by the stone. What is the net displacement and the total distance covered by the stone?
→
Suppose a planet exists whose mass and radius both are half that of the earth. The acceleration due to gravity on the surface of this planet will be double? Justify.
→
What would happen to the life of a cell, if there are no vacuoles?
→
In agricultural practices, higher input gives higher yield. Discuss how?
→