A Vicious Cycle
Farmers are also reluctant to use the most required dose of organic manures for the same reason of lack of visible effect. Organic manures are also difficult to be available as greater rate of mechanization have led to less number of cattle they are to raise in their farmyard. These are not or less available in the locality either, because there are less of empty land nowadays where the poor people can graze their cattle hassle-free. If there are cropped land almost everywhere around, the cattle cannot graze freely, the cattle of the poor landless farmers can graze the crops bringing compensation from the farmers.
In brief, farmers use only Nitrogenous fertilizer (Urea) to the full recommended dose or more and in this way invite more pests to their crops which again compel them to use more chemical pesticides.
This is a vicious cycle. Nitrogenous fertilizers are easy to use and produce greater visible effects on crops. The farmers put in more of urea as nitrogenous fertilizers. The luxurious growth of crops invite pests and the farmers have to run to apply pesticides to save the crops.
Use of only nitrogenous fertilizers makes the crops vulnerable to insect and disease pest attack as the crops tend to become dark green, sappier and tenderer. The pests are lured to attack such crops. So the farmers have to invest more in pesticides to save the crops.