122 CHARLES B. LIPMAN 



to the application. Potatoes were not thus affected, but on the 

 contrary, calcium sulphate and calcium carbonate acted alike 

 for that crop. The injurious effects of gypsum were overcome by 

 applications of either calcium or magnesium carbonate along 

 with it. Its effects were also reduced by mixing loam with sand. 

 When used in small amounts, but only then, magnesia increased 

 the yield of grass and alfalfa; larger applications reduced the 

 yield in the case of that crop mixture. On the other hand, in 

 the case of horse beans and vetch, the yield was not reduced 

 by the application of magnesia. In general, it appeared that 

 the magnesium carbonate was apparently capable of almost com- 

 pletely replacing lime in spite of the fact that the highest yields 

 were always obtained when calcium and magnesium carbonates 

 were used together. 



In the continuation of his investigations above discussed on 

 the effect of hming in growing crops, Ulbrichf^^ carried out an- 

 other series of pot experiments with barley. He found in these 

 that lime ''fertilizers" increased markedly the yield of barley in 

 all amounts used. The weight of the grain in every case was 

 reduced by the application of lime and marl in February. The 

 tillering of the grain was invariably increased by lime and mag- 

 nesia. A heavy lime application plus a heaiy magnesia appli- 

 cation increased all phases of the growth of plants, but the 

 straw more particularly than the grain, and the weight of the 

 grain was less. Heavy applications of magnesian lime reduced 

 the yield of grain and straw. 



Of a much more indirect nature is the investigation of R. 

 Averna-Sacca^^ on the chlorosis of oranges and other plants on 

 ferruginous soils. Soil analyses and pot experiments were car- 

 ried out in an attempt, by various means, to cure grape vines, 

 coffee plants, orange trees, etc., of chlorosis. A large number of 

 remedies were employed and as a result Averna-Sacca concludes 

 that chlorosis is due principally to a deficiency of magnesium and 



^^ Landw. vers. Stat., vol. 57, p. 103. 



"Bol. Agr. (Las Pau'o) 13th Ser. 1914, no. 2, p. 129. Cited from E. S. R., 

 vol. 28, p. 153, 1913. 



