Why is organic matter important for crop production?

Mention two advantages of animal husbandry.

In winter, in the industrialised and metro cities, especially in the morning hours, the visibility is greatly lowered due to the formation of a dark fog, generally resulting in serious road accidents. It also causes suffocation.
$(a)$ What does this indicate and also name this phenomenon?
$(b)$ How is this phenomenon produced? Name two gases which cause acid rain.

To get a better yield,Jaikishan increased the use of pesticides and fertilizers. Though in the initial years he got higher yield,after that,it declined. He was much worried. His friend Mahesh persuaded him to abandon this practice and start using organic manure.
$(i)$ Why are fertilizers used in a field?
$(ii)$ State the possible reason for the decline in yield.
$(iii)$ List two values shown by Mahesh.

Name the type of nutrient that we get from mustard seeds and linseed.

Arrange these statements in the correct sequence for the preparation of green manure.
$(a)$ Green plants are decomposed in the soil.
$(b)$ Green plants are cultivated for preparing manure or crop plant parts are used.
$(c)$ Plants are ploughed and mixed into the soil.
$(d)$ After decomposition,it becomes green manure.