11 



Some results secured by Ilasellioff ' in studying the decomposition 

 of certain rocks are interesting in this connection. Peas, beans, 

 lupines, barley, and wheat were grown in rocks powdered to a fineness 

 of 5 to 0.5 millimeter. Two of the rocks used were sandstone (Bunt- 

 sandstein) and limestone (Musclielkalk). The sandstone contained 

 no carbonate of Ume and the Hmestone about 94 per cent. Barley 

 and wheat, which made almost no growth on any of the rocks, con- 

 tained no more lime when grown on the Hmestone than when grown 

 on tlie sandstone. Peas, beans, and lu])ines, which made a relatively 

 good growth on the sandstone and a greatly diminished growth on the 

 limestone, contained respectively two, five, and three times as much 

 lime in the dry substance wJien grown on the limestone as wlien 

 grown on the sandstone. These results are not conclusive in con- 

 nection with our work, iiowever, as the plants were grown on pow- 

 dered rock without any addition of fertUizera. Thus the growth of the 

 plants was limited mainly by the ease with which the different rocks 

 afforded tlie mineral nutrients, and aii}^ effect whicli the other cliar- 

 acteristics of the rocks could have had upon the plant growth was 

 probably obscured. The results, however, when compared witli the 

 data in tlie following pages, where much smaller increases in lime 

 were induced in the plants, suggest tlie idea that the presence of an 

 abundance of nutrient salts probably decreases the percentage of 

 lime in the asli of plants grown in calcareous soils. 



Studies of D. Meyer - and Lemmermann et al.^ give data showing 

 the influence of the lime content of the soil upon the lime content 

 of the plant. The plants were grown in pots with additions of 

 nitrogen, potash, and phosphoric acid. 



Lemmermann et al. worked with six sods, five of wliich contained 

 from O.OS percent to 0.85 per cent of CaO, while the sixth soil, evidently 

 calcareous, contaiiied 9.25 per cent of CaO. Rye, barley, and oats, 

 grown on the calcareous soil witli 9.25 per cent CaO, contained less 

 lime in the dry substance than when grown on the sods with 0.53 

 per cent and 0.S5 per cent of lime. There was no depression of 

 growth on the calcareous soil as compared with the other soils. Clover 

 grown on the calcareous sod contained the same amount of Ume as 

 wlien grown on the soil with 0.53 per cent CaO. The growths on the 

 different soils were about tlie same. Mustard grown on the calcareous 

 sod contained the same amount of Ume as when grown on the sod 

 with 0.85 per cent CaO, the growths made on the two sods being 

 approximately equal. Vetch grown on the high-lime sod contained 

 more lime than when grown on any of the other soils, although the 

 growth varied but Uttle between the sods containing 0.53 per cent. 

 0.85 per cent, and 9.25 per cent CaO. 



' Ilaselhofl, E., Landw. Vers. Stat., 70 (1909), p. 53. 



s Meyer, D., Landw. Jahrb., 39 (1910), Erganzungsb. 3, p. 254. 



» Lcmmermaim, O., et al., Landw. Jahrb., 40 (1911), No. 1-2, p. 173. 



