Root distribution and soil properties under 12-year old sympodial bamboo plantation in Central Himalayan Tarai Region, India

Worldwide, majority of the studies on root distribution have been confined to different tree species and monopodial bamboos in China with limited information on sympodial bamboos mainly due to methodological complexities. The present study therefore aims at understanding root distribution pattern of six commercial bamboo species and its impact on soil properties. Six bamboo species viz.,Bambusa balcooa, Bambusa bambos, Bambusa nutans, Dendrocalamus asper, Dendrocalamus hamiltonii, and Dendrocalamus strictuswere evaluated for their rooting pattern and impact on soil properties. Coarse root (CR) intensity was maximum inB. bambos(209.2) while, fine root (FR) intensity was highest inD. strictus(594.2). The FR contribution ranged from 69.9% inB. bambosto 80.1% inD. strictus. Coarse root biomass (in 0-50 cm soil profile) was highest inD. hamiltonii(1.19 Mg ha(-1)) and lowest inD. strictus(0.44 Mg ha(-1)). Maximum FR biomass (6.27 Mg ha(-1)) was observed inB. nutanswhich was closely followed byD. hamiltonii(6.19 Mg ha(-1)). In all the species, the share of fine root intensity was higher (70-80%) as compared to coarse roots. The contribution of FR was higher in genusDendrocalamus(D. strictus, D. hamiltoniiandD. asper) as compared to other species in genusBambusa.Depth wise distribution of CR intensity revealed that roots were more or less uniformly distributed in 0-30 cm soil depth while fine root intensity was higher in 0-10 cm where 47% roots were observed. Soil physical properties viz., hydraulic conductivity, water stable aggregates and mean weight diameter showed significant improvement under different species. As compared to control treatment, soil organic carbon, NPK showed significant improvement.D. hamiltoniiandB. balcooawere found better species are better species for maintaining soil fertility status. From the study it could be concluded thatD. hamiltoniidue to higher fine root biomass, is suitably recommended for resisting soil erosion, enhancing ground water recharge and maintaining soil fertility.B. balcooacan be preferred for agroforestry due to less root competition and compact canopy.