EFFECT ON CLOVER OF LIMING THE SOIL. 121 



of clover plants were gathered from both limed and imlimed areas of the 

 plots mentioned in Taljle I. and samples of clover roots from both halves 

 of plots 2, 5 and 7. 



The samples of clover were obtained on Sept. 14 and L5, 1914, when 

 the crops on the hmed halves of plots 4 and 7, without nitrogen, were in 

 full bloom, and on the other Umed areas were parth^ so. The unlimed 

 halves of plots 1 and 2, dressed with nitrate of soda, appeared to be as 

 much in bloom as the limed halves, but the remaining unlimed areas 

 showed no flowers nor buds. The samples were gathered bj' cutting the 

 plants near the ground with grass shears, and each half of a plot was 

 represented by a large number of plants wliich were taken from all sections 

 of it. The unlimed areas of plots 4, 5, 6, 7 and 8 were most thoroughly 

 represented because the growth on them was so much smaller that many 

 more plants were needed to make samples of sufficient size. 



The samples of clover roots were obtamed by digging representati\-e 

 plants with a spade, taking up a block of soil about 8 inches in depth. 

 The blocks of soil were exposed to the action of water from a hose-nozzle, 

 care being taken that the rootlets were not broken as the soil was washed 

 away. The process was slow, and it required the time from September 

 16 to 19, inclusive, to prepare the samples desired. The samples were, 

 however, obtained under uniform conditions, as the weather was fair 

 throughout the samphng. .Aiter the roots were washed free of earth they 

 were cut from the plants and dried. 



The roots from both halves of plot 2, dressed with nitrate of soda, were 

 large and thrifty and bore numerous nodules. The roots from the limed 

 halves of plots 5 and 7 were apparently similar in all respects to those 

 from plot 2. On the other hand, the roots from the unlimed half of plot 

 5, dressed with sulfate of ammonia, were much smaller than those from 

 the limed half, and nodules were few and very small. The roots from the 

 unlimed half of plot 7, receiving no nitrogen, were thriftier than those 

 just described, but were not so thrifty in appearance as those on the 

 limed half and bore smaller nodules. 



All samples were dried at a temperature around 75° C. until sufficiently 

 brittle to be easily pulverized. They were then ground to a powder, 

 after which moisture was determined in order that all subsecjuent analytical 

 work could be based on the dry matter. No attempt was made to de- 

 termine the percentage of drj^ matter as it was not essential. 



The tentative plan for chemical analysis included total nitrogen as the 

 most easily determined organic constituent, total ash as a guide to the 

 mineral constituents, iron oxide and calcium oxide. Iron oxide seemed 

 important because in our soil-fertility investigations Mr. Ruprecht has 

 found soluble iron salts in the unlimed areas of some of the plots, ^ and 

 has studied their effects on the growth of clover. ^ The percentage of 

 calcium oxide in the clover was expected to be mocUfied by the apphcation 



1 Investigations not yet published. 

 - See second part of this bulletin. 



