Biodrainage: An Eco-friendly Agroforestry Technique for Controlling Waterlogging, Livelihood Security and Carbon Sequestration
Biodrainage: An Eco-friendly Agroforestry Technique for Controlling Waterlogging, Livelihood Security and Carbon Sequestrationwca2014-1130 Jagdish C. Dagar 1,*Jeet Ram 2Suresh K. Chaudhri 1Khajanchi Lal 3Mukesh Kumar 3Gurbachan Singh 4 1Soil & Crop Management, Central Soil Salinity Research Institute (CSSRI), Karnal, 2Haryana Forest Department , Forest Services, Panchkula, 3Water Technology Center, IARI, Delhi, 4ASRB, New Delhi, ICAR, New Delhi, India
Introduction of canal irrigation in arid and semi-arid regions without provision of adequate drainage causes rise in ground water table leading to waterlogging due to seepage and secondary salinisation. About one-third of the world’s irrigated area faces the threat of water logging. In India, the total degraded land due to waterlogging is 6.41 M ha. As sub-surface drainage is costly and disposal of effluents has inherited environmental problems, a viable alternative is biodrainage, which is ‘pumping of excess soil water by deep-rooted plants using bioenergy’. The impact of block plantations of Eucalyptus tereticornis was tested and found effective in Indira Gandhi Nahar Paryojana area, where ground water under the block plantation was reported to fall by 15.7 m over a period of six years. In another experiment it was observed that the ground water table underneath the strip plantations was 0.85m during a period of 3 years and it reached below 2m after 5 years. The average above ground oven dry biomass of 5 ½ years old strip plantation was 99.9 kg tree-1 resulting in 24.0 t ha-1 above ground biomass of 240 surviving trees. The average below ground oven dry biomass of roots was 8.9t ha-1 and the total oven dry biomass was 32.6t ha-1. The carbon in the oven dry biomass was 15.5t ha-1. The average transpiration rate (measured by sap flow) of ground water by these plantations ranged from (litres day-1 tree-1) 44.5 – 56.3 in May to 14.8 – 16.2 in January. The annual transpiration rate was equal to 268 mm per annum. The wheat grains yield was 2.15t ha-1 as compared to 0.64 t ha-1 in the nearby un-treated fields without plantation. The farmers earned INR 72000 ha-1 at a rotation of 5 years and 4 months resulting in a benefit-cost ratio of 3.5:1 at 12% discount rate of interest.