Journal of Global Agriculture and Ecology

Java citronella (Cymbopogon winterianus) is an aromatic perennial crop valued for its essential oil, and nutrient management is important for sustaining oil productivity under region-specific soil conditions. The present field experiment evaluated the effects of FYM, graded NPK levels and their combined application on oil content, oil recovery and oil yield of Java citronella under Inceptisol conditions. The experimental soil had moderate organic carbon, low available nitrogen and phosphorus, very high available potassium, and micronutrient concentrations above their critical levels. The study was conducted during the Kharif seasons of 2009–10 and 2010–11 in a randomised block design with thirteen treatments and three replications. Treatments included control, FYM at 5 and 10 t ha⁻¹, graded NPK levels, combinations of FYM with NPK, and 100 kg N supplied through FYM. Oil content and oil recovery were estimated after shade drying and hydro-steam distillation. Combined FYM + NPK treatments produced comparatively higher oil content than the sole application of FYM or NPK. The highest pooled oil content (1.14%) and oil recovery (0.70%) were recorded with 10 t FYM + 140:40:80 kg NPK ha⁻¹. The same treatment produced the highest pooled oil yield (184.42 kg ha⁻¹), exceeding FYM supplying 100 kg N, 140:40:80 kg NPK ha⁻¹ and 10 t FYM + 100:30:60 kg NPK ha⁻¹ by 108.62, 48.16 and 11.58%, respectively. The results indicate that combined use of FYM and NPK was beneficial for improving oil-related traits of Java citronella under the studied conditions.