Biodrainage

Biodrainage may be defined as “pumping of excess soil water using bio-energy through deep-rooted vegetation with high rate of transpiration.”The biodrainage system consists of fast growing tree species, which absorb water from the capillary fringe located above the ground water table. The absorbed water is translocated to different parts of plants and finally more than 98% of the absorbed water is transpired into the atmosphere mainly through the stomata. This combined process of absorption, translocation and transpiration of excess ground water into the atmosphere by the deep rooted vegetation conceptualizes bio-drainage. Fast growing Eucalyptus species like known for luxurious water consumption under excess soil moisture condition are suitable for biodrainage. These species can be planted in blocks in the form of farm forestry or along the field boundary in the form of agroforestry. Other suitable species for block plantations are Casuarina glauca, Terminalia arjuna, Pongamia pinnata and Syzygium cuminii etc.
Experiments were conducted in Haryana state. Plantations were raised in water logged areas of Haryana state. To measure the ground water table observation wells were installed in between the tree plantations. Corbon content of oven dried timber, fuel wood, twings/leaves and roots samples were determined by dichromate oxidation method. The transpiration rate was measured using dissipation probes. The basic dissipation probe has two thermocouple needles inserted in the sapwood, the upper one containing an electric heater. The probe needles measure the temperature difference (dT) between the heated needle and the sapwood ambient temperature below. The dT variable and the maximum dTm at zero flow provide a direct conversion to sap velocity. Girth of all trees was measured at the breast height with the help of a measuring tape.
Four parallel strip plantations worked as bio-pumps and lowered the water table by 0.85 m in 3 years in canal-irrigated, agricultural, waterlogged fields located in a semi-arid region with alluvial sandy-loam soil. The annual rate of transpiration by these plantations was 268 mm against the mean annual rainfall of 212 mm. Lowering of water table and associated improvement by Eucalyptus plantations increased by 3.4 times than the adjacent fields. There was no net increase in ground water table salinity underneath the plantation. The fluctuations in g.w.t. caused fluctuations in g.w.t. salinity underneath the plantation as well as in the adjacent fields. Tree species vary in their “biodrainage potential” as evidenced by the extent of lowering of water table immediately beneath the plantations. Eucalyptus species has a higher biodrainage potential as compared to relatively slow biodariners like T. Aphylla and P.pinnata.

1. welcome

2. Credit Seminar on Biodrainage Course Incharge Dr. G. Ravi Babu Associate Professor & Head Dept. of Soil and Water Engineering By Ch.AppaRao BEM-12-001

3. INTRODUCTION Biodrainage may be defined as “pumping of excess soil water using bio-energy through deep-rooted vegetation with high rate of transpiration.” The biodrainage system consists of fast growing tree species, which absorb water from the capillary fringe located above the ground water table. The absorbed water is translocated to different parts of plants and finally more than 98% of the absorbed water is transpired into the atmosphere mainly through the stomata. This combined process of absorption, translocation and transpiration of excess ground water into the atmosphere by the deep rooted vegetation conceptualizes bio-drainage.

4. Merits of biodrainage over conventional drainage systems Relatively less costly to raise biodrainage plantations No maintenance cost from 3rd year onward No operational cost, as the plants use their bio-energy in draining out the excess ground water into atmosphere. Increase in worth with age instead of depreciation No need of any drainage outfall and disposal of drainage effluent No environmental problem, as the plants drain out filtered fresh water into the atmosphere In- situ solution of the problem of water logging and salinity Preventive as well as curative system for waterlogging and salinity

5. Combined drainage- cum – disposal system Moderates the temperature of the surrounding by transpiration and a cushion for moderating frost, cold and heat wave impacts Helps in carbon sequestration and carbon credits Mitigates the problem of climate change and contributes to increased forest cover Purifies the atmosphere by absorbing CO2 and releasing O2 Acts as wind break and shelter belts in agroforestry system Provides higher income to the farmer due to the production of food, fodder, fuel wood and small timber

6. Where to apply: Thornburn and George (1999) observed that the evaporation from the soil takes place up to a depth of 4 m (Fig. 1). Fig. 1: Relationship between evaporation and water table depth in different soil types

7. CASE STUDIES

8. Title Biodrainage to combat waterlogging , increase farm productivity and sequester carbon in canal command areas of northwest India Scientists Jeet ram et al Journal & Year Current science. vol.100 (11):1673-1680. 2011 Location Puthi village, hisar district, Haryana

9. Fig.2 land locked area of puthi research plot.

10. Fig.3 Layout of puthi research plot.

11. Table 1. Fresh shoot biomass of 22, 5-year and 4-month-old trees of clonal eucalyptus tereticornis .

12. Table 2. Biomass and carbon sequestered by 5-yr and 4 month old clonal E.tereticornis

13. Table 3. Transpiration of groundwater by trees of clonal E.tereticornis

14. Fig.4 wheat yield obtained with and without eucalyptus plantation.

15. Fig.5 effect of plantation on soil electrical conductivity of the saturation extract ( ECe )( ds /m) and ph of the soil saturation paste (pHs).

16. Fig.6 Trend of groundwater table levels in (a) transect I and (b) transect II at Puthi research plot during April 2005 and 2008

17. Conclusions Four parallel strip plantations worked as bio-pumps and lowered the water table by 0.85 m in 3 years in canal-irrigated, agricultural, waterlogged fields located in a semi-arid region with alluvial sandy-loam soil. The annual rate of transpiration by these plantations was 268 mm against the mean annual rainfall of 212 mm. These plantations generated 46.6 t/ha fresh biomass with benefit-cost ratio of 3.5 and also sequestered 15.5 t carbon/ha. Lowering of water table and associated improvement by Eucalyptus plantations increased by 3.4 times than the adjacent fields.

18. Title Biodrainage Potential of Eucalyptus Tereticornis for Reclamation of Shallow water table areas in North West India   Scientists J. ram et al Journal & Year Agroforest Syst . vol.69:147-165. 2007 Location Dhob-bhali research plot , Rohtak district, Haryana

19. Fig. 7 Location of (a) Haryana state in north-west India and (b) Dhob-Bhali research plot in Rohtak district of Haryana state

20. Fig. 8 Layout of Dhob-Bhali research plot. Legend. (•) Observation well,( ) road,( IIIIII ) railway line and ( ) plantation ) road, ( IIIIII ) railway line and ( ) plantation

21. Fig. 9 fluctuations of ground water table during 1974-2004 in rohtak district.legend .(-o-) june and (-^-) October.

22. Fig.10 Trend of ground water table levels in the east-west transect of Dhob-Bhali research plot during (a) pre-monsoon season, (b) monsoon season, (c) post-monsoon season and (d) winter season of 2004–2005

23. Fig.11 Mean trend of ground water table levels in the east-west transect of Dhob-Bhali research plot during 2004–2005 and 2005–2006.

24. Fig.12 Trend of ground water table levels in the north-south transect of Dhob-Bhali research plot during (a) pre-monsoon season, (b) monsoon season, (c) post-monsoon season and (d) winter season of 2004–2005

25. Fig.13 Mean trend of ground water table levels in the north-south transect of Dhob-Bhali research plot during 2004–2005 and 2005–2006.

26. Fig.14 Trend of (a)ground water table salinity and ground water table levels (b) soil salinity and ground water table levels and (c) soil salinity of the zone of capillary fringe and ground water table levels during may 2004 in east west transect. (.) ground water table and (^) salinity.

27. Fig. 15 Fluctuations in g.w.t and g.w.t salinity during May of 2004, 2005 and 2006. Legend. ( ) May 2004, ( ) May 2005 and ( ) May 2006

28. Table 4. ground water table ( g.w.t ) and g.w.t salinity (EC) during may of 2004,2005 and 2006

29. Conclusions The average g.w.t . in the plantations was 4.95 m and the average g.w.t . in the control located in the adjacent fields was 4.04 m and hence, the drawdown of g.w.t . was 0.91 m. Throughout the study of 2 years, the g.w.t . underneath the plantations remained lower than the g.w.t . in the adjacent fields without plantation. The g.w.t . in the plantations was lowered up to a maximum depth of 5.63 m below the ground level. The spatial extent of lowering of g.w.t . in the adjacent fields was up to a distance of more than 730 m from the edge of a plantation. The sinker roots reached the zone of capillary fringe up to a depth of 4.40 m clearly indicating that the Eucalyptus trees were absorbing capillary water of the g.w.t .

30. Title Biodrainage for preventing waterlogging and concomitant wood yields in arid agro-ecosystems in north-western india Scientists O P toky et al Journal & Year Journal of scientific and industrial research . vol.70 :639-644. 2011 Location Haryana Agricultural University, hisar district, Haryana

31. Experimental site comprised of 30 acres (12 ha) of waterlogged land at CCS HAU farm square number 1799-1800 along with Balsamand canal which flows nearly in the east west transact. With a long term view of reclaiming this abandoned waterlogged site, biodrainage plantations have been raised as strip plantations on field bunds which are about 60 m apart from each other. Field bunds were 2.9 m broad at base, 2.6 m broad at top, 0.45 m in height and extend to a length of 150 m from north to south. Two rows of trees were planted on each bund with a row to row distance of 1.3 m. Plant to plant distance was 1.5 m in Eucalyptus and 3 m in other species.

32. Fig. 16—Tree height and diameter at breast height (DBH) of different tree species in September 2009 (CD 5%: Ht 73, DBH 1.7)

33. Fig. 17—Strip plantation of some representative tree species on ridges at the field in university campus: a) Eucalyptus tereticornis C-10; b) Eucalyptus tereticornis C-3; c) Tamarix aphylla ; and d) Prosopis juliflora (marked leaf area is difference between C-10 and C-3 of E. tereticornis )

34. Fig.18 —Leaf area index of different tree species in September 2009 (CD at 5%: 0.17)

35. Fig. 19—Water table immediately beneath each strip plantation with respect to fallow control bund

36. Table 5. water table fluctuations measured as mean of monthly values from a well located 20m east of each bund during experiments

37. Conclusions: Tree species vary in their “ biodrainage potential” as evidenced by the extent of lowering of water table immediately beneath the plantations. Eucalyptus species has a higher biodrainage potential as compared to relatively slow biodariners like T. Aphylla and P.pinnata .