Assessment of Production and Soil Conservation Potential of Aromatic Grasses Grown Under Shifting Cultivated Degraded Hill Slopes of Eastern Ghats, India

Abstract

Unregulated shifting cultivation in Eastern Ghat, India has accelerated soil erosion rates and caused unproductive land area forcing the local tribes to migrate to cities thus bringing demographic change. Therefore, this study evaluates the option to adopt oil grasses which has ability to increase farmers’ income and facilitate efficient soil conservation. The performance of three different oil grasses viz. lemon, citronella, and palmarosa grass, under three types of land slope conditions viz. 4%, 8%, and 12% was studied during 2012–2015. Irrespective of varying land slope, lemon grass performed well in terms of mean total biomass, which was significantly higher compared to citronella and palmarosa grass. This was accompanied by lower annual soil loss and remarkable improvement in soil physical and chemical properties, particularly soil organic carbon (47% increase compared to initial year of study). Essential oil production was recorded higher in citronella grasses outperforming lemon grass and palmarosa grass. Both lemon and citronella grass exhibited a greater reduction in runoff coefficient and soil loss during the four-year study period. However, lemon grass showed minimal variability in total biomass production over a period of three years, thus indicating greater yield sustainability and assured income for farmers. The study underscores the potential of oil grass cultivation as a sustainable alternative to shifting cultivation in degraded sloping lands of Eastern Ghat region, Odisha, India and promulgate widespread adoption of oil grasses to revive the ecological balance and sustain the livelihood of tribal farmers. Lemon and citronella grasses emerge as viable options for economic returns and soil conservation, with lemon grass exhibiting consistent performance across varying slope gradients.