Effect of conjunctive use of FYM and nitrogen on yield, quality and economic of FCV tobacco (Nicotiana tabacum)

Abstract

A field experiment was conducted during 2001-02 and 2002-03 at Rajahmundry, Andhra Pradesh to find out op- timum level of farmyard manure (FYM) and nitrogen for getting higher productivity, quality, monetary returns of to- bacco ( Nicotiana tabacum L.), and changes in soil fertility after tobacco. Application of FYM @10 t/ha, being com- parable with 20 and 30 t/ha, significantly increased mean yields of green leaf by 16.8, cured leaf by 15.6, bright leaf by 25, grade index by 20.2 and cured leaf production efficiency by 15.6%; the lamina N P and K uptake by 22.2, 21.0 and 18.9%; the residual soil organic C, available N and P by 0.08, 6.6 and 15.5%, respectively than that of no FYM application; and also accrued the highest net returns (Rs 25,800/ha), benefit : cost ratio (1.47) and prof- itability (Rs 191.11) compared with those of other FYM levels. Application of 40 kg N/ha, being comparable with 60 kg N/ha, significantly increased mean yields of green leaf by 9.5, cured leaf by 8.0, bright leaf by 12.8, grade index by 8.1 and cured leaf production efficiency by 7.9%; the lamina N and K uptake by 18.3 and 17.1%, respectively; the residual soil available N by 4.2% compared with those of 20 kg N/ha application; and also accrued highest net returns (Rs 23,590/ha), benefit : cost ratio (1.42) and profitability (Rs 174.74/ha/day) compared to those of 20 and 60 kg N/ha application. Increasing the rate of N fertilizer from 20 to 60 kg N/ha increased the concentration of total N, nicotine and decreased sugars and sugar : nicotine ratio in tobacco cured leaf. Conjunctive application of 10 t/ ha of FYM and 50 kg N/ha was found optimum for obtaining higher yields and better grade index of tobacco with acceptable chemical quality parameters and higher monetary returns under conserved soil moisture conditions in Vertisols of Andhra Pradesh.