118 ALFALFA FARMING IN AMERICA. 



anything can stand before healthy alfalfa. Almost 

 any weed will conquer unhealthy alfalfa. Lime is 

 its tonic, its heal-all. 



Amount of Caustic Lime. — ^How much caustic lime 

 will we dare use I In an acre of soil, counting the 

 top foot, there are roughly about 2,000 'tons. The 

 sweetening of this mass of soil cannot be accom- 

 plished by any handful of lime. One ton to the acre 

 is one part in 2,000; two tons to the acre is one- 

 tenth of one per cent, of lime. It would seem folly 

 to use less than two tons to the acre of caustic lime. 

 Double that, well distributed, would almost cer- 

 tainly do harm. Is there a man who has harmed his 

 soil by putting in it four tons of caustic lime to the 

 acre, seeing that it is well distributed, and that the 

 land has good store of humus, and has then sown it 

 to alfalfa? 



Caustic lime must not be supposed to remain 

 caustic for a long time after it is applied to the soil. 

 It soon absorbs carbon again and becomes a neutral 

 and harmless substance. This being true, why not 

 use some form of carbonate of lime in the begin- 

 ning'? The only answer is that it is sometimes 

 cheaper, because of freights or lack of machinery 

 for grinding, to use the burned lime. 



Other Forms of Lime. — Now for some other forms 

 of lime. Air-'slaked lime, as has been said, has 

 absorbed a lot of carbon and is not nearly so biting 

 and caustic as the fresh burned lime. It is fre- 

 quently for sale at a comparatively low price, be- 

 cause it is a waste product about lime kilns. It is 



