180 



SCIENTIFIC AGRICULTURE. 



THE LIMING OF SOILS. 

 Part II.— (Concluded.) 



PLANTS USUALLY OR FREQUENTLY INJURED BY LIMING, 



Among the plants which have shown slight injury from liming under certain 

 conditions and which may under other circumstances be helped by it are the 

 following :— Cotton, tomato, cowpea, zinnia, phlox (Drummondi), Concord grape, 

 peach, apple, and pear. The plants that have quite persistently shown marked 

 injury from liming are: Lupine, common sorrel, radish, velvet bean, flax, castor 

 bean, blackberry, black-cap raspberry, cranberry, Norway spruce, and American 

 white birch. Extensive European tests have also shown that lupine is injured by 

 liming. Lime, though directly injurious to common sheep sorrel, aids in ridding 

 land of it more by virtue of encouraging other plants than on account of the direct 

 injury which it causes. It is claimed that the chestnut, azalea, and rhododendron 

 are injured by lime, though they have not yet been tested at the Rhode Island 

 Station. 



The Rhode Island soil upon which the tests referred to were made is what 

 has been termed a " silt loam," in which the water table is usually from 12 to 15 

 feet below the surface. 



INFLUENCE OF LIME UPON SOME PLANT DISEASES. 



Potato Scab.— It has been shown that carbonate of lime and such other 

 compounds of lime as are changed into the carbonate by decomposition within 

 the soil all tend to favor the production of potato scab, provided the germs of the 

 disease are already in the soil or are introduced into it ou the seed tubers. This 

 seems to be due to the fact that the lime makes the soil alkaline, or to some influence 

 which the combined carbonic acid of the carbonate of lime exerts upon the develop- 

 ment of the fungus. 



In view of this unfavorable action of lime caution should be observed in 

 liming potato fields in the manner suggested on a previous page. 



Club Root.— Many writers seem to agree that liming is capable of lessening 

 materially the injury to turnips, cabbages, etc., caused by the disease known as 

 " finger-and-toe " and " club root." English writers assert that by resort to liming 

 excellent crops of turnips have been produced where without it the crop was a 

 failure, owing to the attacks of the disease. 



Other Diseases.— The effect of different compounds of lime has been tested, 

 with not entirely conclusive results, on various other diseases, including cranberry 

 and sweet potato diseases, and a root disease of alfalfa (Rhizoctonia medicaginis). 

 Slaked lime Avas found to be effective in reducing soil rot of sweet potatoes, and 

 quicklime in checking or preventing the root disease of alfalfa. 



HOW OFTEN SHOULD LIMING BE PRACTISED ? 



The frequency with which liming should be practised depends upon several 

 conditions ; for example, upon the character of the soil, the quantity of lime 

 employed in each application, the number of years involved in a rotation, the 

 plants to be grown and their order of succession. Formerly, in England, large 

 quantities of lime were applied at somewhat rare intervals, but there and elsewhere 

 at the present time the preferable practice seems to be to use small amounts and 

 apply it more frequently. As a general rule it may be stated that from half a ton 



