Besides oil, can I earn from vetiver khus roots, grass and erosion control work?

Yes, vetiver (khus) has several income streams beyond the perfumery oil, which is one reason it is a versatile crop. The dried fragrant roots are used to make khus tatti (cooling screens and mats) and other craft and cooling products, and there is a small market for dried khus roots for this and for cooling drinks and traditional uses. The plant is widely valued for soil and water conservation: its deep dense roots stabilise bunds, field edges, canal banks, slopes and degraded land, and there is demand for vetiver slips (planting material) for such conservation and landscaping work, which can be sold to other growers, departments or projects. The grass tops can be used as mulch or rough fodder in some cases. That said, the oil remains the main commercial value for most growers, and the side uses are usually supplementary rather than a substitute. Each of these markets is local and limited, so do not assume large income from them; check what actually sells in your area. The realistic picture is that khus can pay through oil as the main product, with roots for craft, slips for conservation planting, and the erosion-control benefit on your own bunds as useful extras. Verify any buyer and price for roots or slips before counting on it, and get terms in writing for any bulk supply deal.