Abstract
Grewia optiva J.R. Drumm. ex Burrett (Bhimal), a medium sized tree has been an integral part of the Agroforestry Systems of North Western and Central Himalayas. It is primarily grown for its nutritious fodder especially at a time when no other fodder is available during the lean winter season (November to February). High yielding provenances of bhimal (I.C.Bhaintan, I.C. Chamba and I.C. Malas) were characterised in respect of various root growth characteristics viz., soil binding, specific root length, horizontal and vertical root spread at quarterly intervals. The entire root system was excavated using skeleton method. Significant differences were recorded in root kinetic parameters for different provenances when studied over two years. Fine roots (<0.5 mm diameter) produced more total root length than coarser roots while the root biomass was the highest for coarse root category in all the provenances. Horizontal root spread was 251.3, 242.3, and 232.6 cm for I.C. Bhaintan, I.C. Chamba and I.C. Malas, repectively after two years and eight months of planting. One of these provenances I.C. Chamba had established itself 1.5 m deep after 23 months of planting while the final vertical spread of roots after the end of study ranged from 230 (I.C. Chamba) to 235 cm (I.C Bhaintan, and I.C. Malas). Soil binding factor was the highest in I.C. Malas (1975.8) followed by I.C. Chamba (1772.8) and I.C. Bhaintan (1674.7) and similar trend was recorded in respect of total root length. Soil binding factor of different provenances of bhimal was substantially higher than recorded for other multi purpose trees (MPTs) in other studies.
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