In-Situ Soil Moisture Conservation In Bamboos For The Rehabilitation Of Degraded Lands In The Himalayan Foothills

Land degradation by water erosion is a major problem in Himalayan foothills. Bamboos due to fast growth, annual culm production, dense root network and high litterfall have enormous potential for checking soil erosion. The establishment of bamboos using in-situ soil water conservation measure can be an effective strategy for the rehabilitation of degraded lands. The study evaluates the efficacy of different types of rainwater harvesting trenches (rectangular, semi-circular and V-shaped) in augmenting the growth and biomass of two important bamboo species (Dendrocalamus strictus and Dendrocalamus hamiltonii) and their combined effect on soil and water conservation. In general, growth parameter in both the species was significantly higher under trenching treatments than the control, with higher values obtained in semi-circular trenches followed by Vshaped or rectangular trenches. Semi-circular trenches depicted 16% higher soil moisture as compared to control treatment (without trenches) irrespective of bamboo species. Soil moisture was 45% higher in D. hamiltonii and 25.1% higher in D. strictus as compared to fallow treatment during the summer season, while, in the winter season, soil moisture was 27.6% higher in D. hamiltonii and 14.5% higher in D. strictus as compared to fallow. In the year 2018, 40.7% of the trenches were silted up in V-shaped treatment, 52.4% in rectangular and 54.8% in semicircular trenching treatments. Silt deposition was higher under D. hamiltonii (50.1%) as compared to under D. strictus (48.6%). Runoff and soil loss were drastically reduced with the age of the plantation. No runoff and soil loss was observed after the fifth year of plantation thereby indicating the efficiency of in-situ water harvesting measures and bamboos in checking soil erosion. It is recommended that in Himalayan foothills, D. hamiltonii species in conjunction with semicircular trenches can be an effective strategy for land rehabilitation.