000			02205nam a2200193Ia 4500
008			140323b2006 xxu||||| |||| 00| 0 eng d
082			_aWP 2006-12-03 (1994)
100			_aGirja Sharan _967076
245			_aCropping in arid area greenhouse by G. Sharan and Kamlesh Jethva ( Working Paper No. 2006-12-03 1994)
260			_aAhmedabad _bIndian Institute of Management _c2006
300			_a16 p.
520			_aIn hot, arid regions, yields are low and unstable, growing season limited to one. Greenhouses can stabilize and improve yields and extend seasons. But their adoption is impeded by the requirement of large amount of water for (evaporative) cooling. Arid Area Greenhouse (AAG) is being developed to reduce or eliminate this need by employing earth-tube-heat-exchanger (ETHE). A prototype AAG was installed in the year 2002 at village Kothara (kा 23ंX 14 N, kी 68ंX 45 E, at 21 m a.s.l.). AAG is of 20 X 6 X 3.5 m size. ETHE is buried 3m deep and coupled to AAG in closed-loop. ETHE provides 20 air changes per hour. There is provision of closable vents - two along the base of long sides and one along the ridge. A retractable shading curtain is provided over the roof. By now five rounds of cropping have been done. ETHE was able to heat the greenhouse from 9ंX C to 22-23ंX C in half hour in the cold winter nights. Static ventilation along with shading was effective for day time control till early March. Subsequently ETHE was operated. It limited the greenhouse temperature gain to just 2.5ंX C. Yield of tomato was 1.5 to 2 times, water used 44% of that in open-field. Water used was mostly for plants, only a small part was for floggers which were some times needed as supplement. ETHE and natural ventilation hold promise as environmental control devices for greenhouses in hot arid regions.
650			_aArid environment _975813
650			_aGreenhouse _960516
650			_aEarth Tube Heat Exchanger _974273
700			_aJethva, Kamlesh _975814
942			_cWP
952			_w2009-09-04 _A00000.00 _BINR _C23/12/2006 _pWP001994 _r2009-09-04 _40 _00 _bVSL _10 _oWP 2006-12-03 (1994) _d2009-05-05 _70 _2ddc _yWP _aVSL
999			_c72086 _d72086