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Alfalfa m at its best when grown under irrigation, 

 which fact indicates its response to large amounts of 

 water judiciously applied. In humid regions alfalfa is 

 pre-eminently a crop for valleys, because on these low 

 levels there is a relative abundance of moisture even dur- 

 inc: drv seasons. On the other hand, the roots of alfalfa 

 in congenial, well drained, permeable soils, penetrate to 

 great depths in search of moisture. But with the poor 

 drainage in a large part of the south" this habit of alfalfa 

 is not fully utilized. The need for ample supplies of 

 moisture can be better understood by the statement that 

 ordinarily hay plants must pass through their leaves 

 about 400 tons of water for every ton of hay produced, 

 or 1,600 tons of water per acre for every crop of four tons. 



Drainage, important for most ordinary farm crops be- 

 cause of the need of the roots for air, and because of 

 tlie deeper growth of roots in drained soil, is doubly im- 

 portant for any leguminous or soil-improving plant like 

 alfalfa. For not only do the roots of such plants need 

 water, but the nitrogen-fixing bacteria in the root tuber- 

 cles must have thorough soil ventilation in order to per- 

 form their work of transforming the valueless nitrogen 

 of the air into the valuable nitrogen of plant food. What- 

 ever may be thought by some of the sufficiency of shallow 

 ditches and levees for draining prairie land sufficiently 

 for cotton and corn, it is certain that such mere surface 

 drainage is insufficient for alfalfa, as, indeed, we believe 

 it to be for the maximum results with other crops. Deep- 

 er ditches are needed for alfalfa. 



No arirument is needed to shoAv the greater convenience 

 and saving of land and work if some of these ditches 

 could be converted into underground drains, whether box 

 drains of plank, pole drains, or Avhether tile be the mater- 

 ial employed. If tile drainage in Alabama can 

 be shown to be cheap enough and continuously 



