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 Essential plant nutrients (16)-
 C, H, O, N, P,K,S,Ca, Mg, B,Cl, Cu, Fe, Mn, Mo, Zn
 Types-mineral nutrients, non-mineral nutrient
 Non-mineral nutrient
▪ C, H, O
 Mineral nutrients
▪ Macronutrients-N, P, K, Ca, Mg, S
▪ Micronutrients

 Fertilizers are added to soil to increase the
supply of plant nutrients
 Natural and artificial fertilizers
 Inorganic fertilizers-nitrogenous, phosphatic
or potash fertilizers

 Nitrogenous fertilizers
 Urea
▪ NH2CONH2 + H2O  NH3 + CO2
 Calcium cyanamide
▪ CaCN2 + 3H2O  Ca(OH)2 + NH2CONH2
 Ammonium salts
▪ Ammonium sulphate, ammonium nitrate, CAN

 Potash fertilizer
 KCl, K2SO4
 Phosphatic fertilizer
 Calcium superphosphate –mix of calcium
dihydrogen phosphate and calcium sulphate
 Triple super phosphate- calcium dihydrogen
phosphate , Ca(H2PO4)2
 Both are water soluble and easily assimilated y
plants

Multinutrient fertilizers
 NP Fertilizers
 ammonium dihydrogen phosphate, diammonium
hydrogen phosphate
NK fertilizers
Potassium nitrate
NPK fertilizers
Mixed fertilizer-KCl/ K2SO4 + Calcium superphosphate
+Ammonium sulphate/ ammonium nitrate
NPK value -% of N2, P2O5, K2O (Eg: 17:17:17)

 Insecticides
 Organochlorines (DDT, BHC, Endosulfan)
 Organophosphates (parathion, malathione)
 Carbamates (aldicarb, carbofuran, carbaryl-sevin)
 Herbicides/ weedicides
 2,4-D; 2,4,5-T; Me. Bromide, diurone
 Rodenticides
 Zinc phosphide, sodiun fluoroacetate, thallium,
warfarin, bromethalin etc
 Fungicides
 Nabam, metham sodium, ziram, captan, ethl mercuric
acetate etc.

 Environmental hazards
 Non-biodegradable
 Biomagnify
 Toxicity
 Affects central nervous system
 Eg-endosulphan

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