1906.] LIMING SOILS AND PLANTS. 81 



A SPECIAL STUDY OF THE INFLUENCE OF LIMING UPON DIF- 

 FERENT VARIETIES OF PLANTS. 



In 1893 four adjacent plats of land of exceptionally uni- 

 form character were secured for more extended experiments 

 with lime. Observations were already on record concerning 

 the natural herbage of calcareous and other soils, and also 

 many miscellaneous observations as to the effect of lime upon 

 the growth of a few varieties of agricultural plants. It was, 

 for example, well understood that lupines are usually injured 

 by liming and that clover is helped by it. Nevertheless no one 

 had ever taken up the study in a continuous and systematic 

 manner, and so far as concerned the vast majority of agricul- 

 tural plants little or nothing was known concerning the in- 

 fluence of lime or of soil acidity upon their growth. In order to 

 study this matter experiments, which are still in progress, were 

 begun in 1893 upon four plats of land, separated by three-feet 

 paths. The plats have all been manured alike with mag- 

 nesium sulphate (Epsom salts), dissolved bone-black (or acid 

 phosphate), and muriate of potash, from the beginning of the 

 experiment to date. Two of the plats received their nitrogen 

 in nitrate of soda and two in sulphate of ammonia. The ab- 

 solute amount of nitrogen used upon each plat is nevertheless 

 kept identical. One of each of these pairs of plats was limed 

 in 1893 and 1894 and again recently. 



The central path shown in this view passes between the 

 two plats which receive sulphate of ammonia. The unlimed 

 plat is at the right. It may be seen in the background that 

 some varieties of plants are making a good growth even upon 

 this plat. The two plats which receive nitrate of soda are in- 

 distinctly or partially seen at the left. 



In this view are shown the two plats manured with nitrate 

 of soda, the unlimed one being at the right. Here also the 

 marked effect of liming upon certain varieties of plants is no- 

 ticeable. 



With the exception of one or two }ears a large number of 

 Varieties of plants have been grown in rows annually across 

 the four plats. 



The plat receiving nitrate of soda and lime is now slightly 

 alkaline to litmus paper. In other words it now turns red 

 litmus paper blue instead of turning a blue litmus paper red, 

 Agr. — 6 



