RESUMO
Tropical grasses are the primary source of forage for livestock and a valuable resource for improving soil health and environmental sustainability in semi-arid regions. A study was carried out in a semi-arid region of central India to determine the short-term (6-year) impact of nine range grasses on soil physio-chemical and biological properties, carbon stock, and forage security. The experiment was carried out in a randomized block design with three replications. Results show that the majority of the grass roots were distributed in the upper soil layer (0-10 cm, 63.5-76.5 %), and then in the middle (10-20 cm, 21.3-25 %) and lower (20-30 cm, 2.2-11.5 %) layers. Perennial tussock grass (Heteropogon contortus (L.) P. Beauv. ex Roem. & Schult) had a higher root volume (2219 mm3), followed by Guinea grass [Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs] (1860 mm3). A lower soil bulk density (BD, 1.11-1.23 g cm-3), higher gravimetric water content (GMW, 14.0-17.8 %), and soil organic carbon (0.38-0.73 %) were recorded for grass-cultivated plots compared to the barren land (1.38 g cm-3, 13.0 %, and 0.28 %, respectively). The perennial tussock grass and Guinea grass resulted in the highest soil microbial biomass carbon (SMBC, 70.1 mg kg-1 soil) and enzyme activities (dehydrogenase, 17.09 µg TPF g-1 day-1 and fluorescein diacetate activity 4.94 µg fluorescein g-1 h-1). The considerable improvement in soil properties with minimal inputs resulted in a higher sustainable yield index and carbon sustainability index in plots planted with Guinea grass (0.9 and 89.29) and perennial tussock grass (0.89 and 71.61). Therefore, the cultivation of either Guinea grass or perennial tussock grass as an intercrop or sole crop in the semi-arid environment can be an ecologically sound strategy to improve soil health, C sequestration, and fodder supply.