THE LIME-MAGNESIA RATIO 87 



spiration of the former by T. Furuta and K. Aso, dealing with 

 the subject of the proper ratio of Hme to magnesia for various 

 plants. Furuta^ found when working with soil mixtures in 

 which there were fixed ratios of lime to magnesia, that the neces- 

 sary ratios vary from 3 of lime to 1 of magnesia, and from 1 of 

 lime to 2 of magnesia with such crops as cabbage, buckwheat, 

 and oats. Furuta makes the claim that in plants producing 

 heavy foliage, the ratio should be 3 to 1, whereas for plants with 

 smaller leaf surfaces, hke those of the cereals, a ratio of 1 to 1 is 

 desirable. 



Three papers have appeared from the pen of K. Aso. In the 

 first^ of these, examples are given of the unfavorable effects in 

 laboratory experiments obtained with improper ratios of lime 

 and magnesia, allowing of the excess either of lime or of mag- 

 nesia. The ratio for favorable growth is indicated for barley, 

 soy beans, and onions. The claim is further made that calcium 

 and magnesium in soils should be determined so that their 

 amounts may be known in the practical management of soils 

 and not only that the total forms of Time and magnesia should be 

 determined, but that the ''available" quantities of these mate- 

 rials, should be ascertained. When soils are limed these figures, 

 according to Aso, should be borne in mind. That author also 

 points out the markedly poisonous effects of magnesium oxide 

 in the absence of lime, and the influence that the latter exerts in 

 increasing the number of root hairs and therefore the total ab- 

 sorbing surface of the root. 



In the second paper^ the mulberry tree instead of rice was 

 studied in a similar way. The experiments with that plant are 

 said to indicate that the normal development of the mulberry 

 tree depends to a considerable extent on the lime-magnesia ratio 

 of the soil. Here again pot experiments were employed and ra- 

 tios of lime to magnesia were made to vary between 1 to 3 and 

 4 to 1 . The net result is claimed to have been the establishment 

 of a ratio of 2 to 1, as the proper one for the mulberry tree. Ex- 



3 Bui. Col. Agr. Tokyo, Japan, vol. 4, p. 371, 1902. 

 * Bui. Col. Agr. Tokyo, Japan, vol. 4, p. 361, 1902. 

 5 Bui. Col. Agr. Tokyo, Japan, vol. 5, p. 495, 1903. 



