1906.] LIMING SOILS AND PLANTS. lOI 



tnres is increased by the higli percentage of reverted phosphoric 

 acid which it contains which raises the phosphoric acid which 

 is reported as " available." Furthermore it makes the mixed 

 fertilizers drill far more readily. 



Notwithstanding the high percentage of " available " phos- 

 phoric acid which it carries it has been found at the Rhode 

 Island Station that this roasted Redondite has but little value 

 for most crops if used upon very acid unlimed land. Liming 

 raised its efficiency for most of the crops tested, in a most strik- 

 ing manner. These results ought to show the importance of 

 putting the soil in the proper condition, if the best results are 

 to be expected from ready mixed commercial fertilizers which 

 contain this material. It is equally important not to go to the 

 other extreme and over lime, for by doing so the tendency 

 would be to lessen the efficiency of the phosphoric acid in bone 

 and tankage. 



LIMING INCREASES THE EFFICIENCY OF ORGANIC NITROGENOUS 



MANURES. 



The absence of a sufficient amount of carbonate of lime and 

 the existence of a high degree of soil acidity have already been 

 shown to reduce the efficiency of nitrogen in sulphate of am- 

 monia. If plants are grown which are very subject to injury 

 upon acid soils even nitrate of soda cannot exert its normal 

 effect and much of it will be lost by leaching, before the next 

 season. The danger of financial losses in the case of the or- 

 ganic nitrogen is also great if the soil is very acid and in great 

 need of liming. This is also well shown by an experiment con- 

 ducted at the Rhode Island Station. The same amounts of 

 potash and phosphoric acid were used in all cases. The nitro- 

 genous substances were applied at such rates as to furnish in 

 every instance identical amounts of nitrogen per acre. 



Upon the limed soil the sulphate of ammonia lost its tox- 

 icity and the efficiency of its nitrogen amounted to 92.2 as com- 

 pared with that in nitrate of soda placed at 100. Upon the 

 same basis of comparison with nitrate of soda, the efficiency of 

 the nitrogen in dried blood which was 45.5 before liming was 

 90.3 afterward, and that of roasted leather was increased by 

 liming from 0.9 to 13.8. Expressed in more direct language, 



