Find out the correct sentence about manure:
$(i)$ Manure contains large quantities of organic matter and small quantities of nutrients.
$(ii)$ It increases the water holding capacity of sandy soil.
$(iii)$ It helps in draining out of excess of water from clayey soil.
$(iv)$ Its excessive use pollutes environment because it is made of animal excretory waste.

Discuss the role of hybridisation in crop improvement.

After combing his hair,Sameer kept the comb on the table where some pieces of paper were lying. He observed that the plastic comb attracted small pieces of paper. He was surprised to see this and asked his teacher about it. His teacher explained to Sameer that matter contains charged particles and that an electrically charged object can attract an uncharged object. Specifically,upon rubbing with dry hair,a comb acquires an electric charge,which then attracts the pieces of paper.
$(a)$ Give any other practical application of this.
$(b)$ What kind of qualities are shown by Sameer?

Write four methods of weed control.

Identify two crops from the following which provide us carbohydrates for energy requirement:
Black gram,Wheat,Lentil,Rice

Name any one method of incorporating desirable characters into a crop variety.