Chemistry is used in agriculture to make fertilizers which are chemical substances. Fertilizers are added to soil to improve the fertility of the soil.
For example, superphosphate, urea, potassium sulphate, etc.
In agriculture we use insecticides which are again made with the help of chemistry. Insecticides are used to kill the insects that infect and destroy the crops
For example BHC (benzene hexachloride), nicotine, etc.
In agriculture fungicides are used. Fungicides are the chemical substances that are used for destroying fungi, which destroy crops.
For example copper sulphate pentahydrate and hexachlorobenzene.