Long-term studies on yield, quality and soil fertility of lemongrass (Cymbopogon fiexuosus) in relation to nitrogen application

Summary A field experiment was conducted over five years (1992–97) at Bangalore (13.58N, 77.558E, 930.m above mean sea level) to study the effect of nitrogen application (0, 50, 100 and 150.kg N ha–1 year–1) on yield, oil quality and soil fertility of lemongrass (Cymbopogon fiexuosus) in the semi-arid tropical conditions of South India. Fresh herbage yield of lemongrass differed significantly between years; the yields increased up to the second year after which they started to decline. During the five years, the response to nitrogen was linear, while still maintaining the same content and quality of essential oil. The oil content and chemical composition of oil did not change as the crop aged. Application of nitrogen and phosphorus maintained the fertility of the soil while potassium depletion was noticed.