To use or not to use chemicals on your garden

There is a growing concern these days about the safety of the food that we eat because farmers are increasingly using agricultural chemicals. 
They use herbicides to kill weeds and they also use pesticides to fight pests both when the crops are still growing in the gardens and after they have been harvested.
 
The process involves spraying, dusting, and fumigation of crops with poisonous chemicals to kill the weeds and the pests so that ultimately the farmers don’t lose the crops. 
Farmers also use manufactured fertilisers to boost plant growth vigour and yields.
The farmers however have the option to use natural methods of controlling pests and weeds. 
Some of the ways to do this include mulching so that when the soil surface is all covered up the weeds are denied space in which to grow.
  
Weeds can also be physically removed by uprooting or by using a hand hoe. For fertiliser, famers can use farm-yard manure and decayed plant material. 
They can also engage in such practices as crop rotation or early planting to fight pest attack. Some farmers go for pest resistant crop varieties. Agricultural chemicals must be bought from shops and most poor farmers cannot afford to use them. 

Yet not all poor farmers have access to natural alternatives such as livestock manure or pest resistant crop varieties. 
If a farmer does not use herbicides to kill weeds then he will probably physically use the hand hoe to remove the weeds, which is time consuming, or he will resort to hired labour, which is rather expensive. 
If a farmer has a large piece of land it might be difficult to get sufficient natural fertilisers such as urine or cow dung.