How is spraying different from fumigation?

To solve the food problem of the country,which among the following is necessary?

For what reasons are improved poultry breeds developed?

$(i)$ Poultry is India's most efficient converter of low-fibre foodstuff into highly nutritious animal protein food. Justify the statement.
$(ii)$ What do we call the birds which are reared for eggs and those which are reared for meat?
$(iii)$ Name one indigenous and one exotic breed of poultry.

How do Sunhemp or guar help in crop production management? How is it better than fertilizers?

Sehaj tried to set up a small kitchen garden in his backyard. However,the soil was sandy and unsuitable for growing vegetables. Within seven days,he solved the problem and started planting seedlings.
$(a)$ Why was the soil in Sehaj's backyard unsuitable for growing vegetables?
$(b)$ What could be the solution he found? Mention any two.