Effect of soil fertility and integrated plant nutrition system on yield, response and nutrient uptake by aggregatum onion

Field experiments were conducted following the Inductive cum targeted yield concept, to study the effect of soil fertility and Integrated Plant Nutrition System (IPNS) on the yield of onion (var CO 4) in Typic Ustropept soils of Tamil Nadu. The treatments consisted of five levels of N, four levels of P₂O₅, three levels of K₂O, two levels of FYM and two levels of Azospirillum (Azo). Marked fertility built up due to fertiliser addition at graded levels was recorded. The bulb yields as well as uptake by onion increased with increase in dose of fertiliser N, P₂O₅ and K₂O and also with application of FYM and Azospirillum. Response to fertiliser nutrients was also recorded.