The Wolnirn Pot-Culture Experiments, 1910-11-12. 335 



As regards the grain, it was noticed each year that as more 

 lime was added the tendency was to produce a more glutinous 

 wheat, for, while the grain of the untreated set was each year 

 quite " starchy," the other sets were distinctly glutinous. This 

 is further borne out by the nitrogen determinations as given in 

 the tal>le. 



The remaining feature of note is with regard to the root 

 development. Between the roots of the untreated sets and 

 those to which lime had been added there was a distinct 

 difference, the latter showing the same fine hairy and increased 

 development that was exhibited when magnesia had been 

 added, and this, it has now been clearly established, is 

 associated with greater nitrogen contents of tlie grain and the 

 formation of a more glutinous wheat. 



The general conclusion to be drawn from this three years' 

 experiment is directly confirmatory of that found in the 

 previous series where magnesia was added, viz., that when 

 magnesia is in excess of lime in a soil then there is likely to be 

 an impairing of the soil's productiveness, and that as the ratio 

 of lime to magnesia more nearly approaches that of 1 : 1, so 

 benefit will accrue. The important practical outcome of the 

 work is to show that soils in which magnesia is in excess of 

 lime will be greatly remedied by the addition of lime, until the 

 proportions of lime and magnesia be equal in amount. 



•4. Experiment of 1912. 



The soil (Hereford) had, up to the close of the 1911 

 experiment, received additions of lime, bringing the percentage 

 from 1*50 per cent, up to 2*25 per cent., at which latter point 

 the lime present equalled the magnesia. Having seen earlier 

 the effect of throwing the magnesia into excess of the lime, it 

 was decided to ascertain, in 1912, whether throwing the lime 

 into excess would produce equally disastrous results ; whether, 

 in effect — to give a practical turn to the enquiry — excess of 

 lime in a soil was as harmful as excess of magnesia. To do 

 this, the same soil was again used, turned out and well aerated, 

 the artificial manure added, and then additional lime given so 

 as to make the soil contain respectively 2'5 per cent, lime, 

 3 per cent., 3'5 per cent., 4 per cent., and 4*5 per cent. This 

 final addition represented the ratio of lime to magnesia 2 : 1 — 

 the original soil, it will be remembered, containing lime "83 

 per cent., magnesia 2*29 per cent. 



Wheat (" Square Head's Master ") was sown in the pots on 

 November 21, 1911. The appearance of the shoots was very 

 irregular, for while with the " untreated " set OO per cent, had 

 appeared in 25 days after sowing, in some cases of the " lime 

 treated " lots 80 per cent, had appeared by then. It was hard, 



