1032 Summary of Agricultural experiments, [march, 



nitrogen during the process of making. Every precaution possible in 

 practice was taken to guard against loss. This result agrees so closely 

 with that obtained by other English and German investigators that it 

 must be regarded as an inevitable part of the process! 



The loss is more serious than it appears, for it falls entirely on 

 the quickly available nitrogen compounds; there is also a further loss, 

 since some of these compounds are taken up by micro-organisms and 

 converted into slowly available and less useful substances. No method 

 can be suggested whereby these losses can be obviated. 



In making dung peat moss is much better than straw as litter, 

 because of its greater power of absorbing and retaining the soluble 

 nitrogen and potash compounds of the urine. But it decomposes less 

 rapidly in the soil, and on light soils peat moss dung may be less 

 useful than straw dung, especially in dry seasons. 



Bracken is a useful material for litter, being nearly as good as 

 straw, but the resulting dung is more useful on heavy than on light 

 soils, because it decomposes less rapidly than straw-made dung. 



It was found that a linseed cake poor in oil produces better dung 

 than a high grade linseed cake, since it contains a larger amount of 

 protein. 



The Composition of Brewers' and Distillers' Grains (Edin. and 

 East of Scotland Coll. of Agr. Bull. XVI.) — This report gives a 

 number of analyses of wet and dry grains, and discussess the varia- 

 tions in their composition and the difference between distillers' and 

 brewers' grains. 



The Effect of Partial Sterilisation of Soil on the Production of 

 Plant Eood (Jour. Agric. Science, Vol. III., Pt. 2, Oct., 1909).— This 

 is a report by Dr. E. J. Russell and Dr. H. B. Hutchinson. When soil 

 is partially sterilised it is found to become more productive, and these 

 investigations were undertaken to ascertain the cause of this productive- 

 ness. Partial sterilisation of soil was effected in three ways : — (1) By 

 heating to 98 0 C. ; (2) by addition of 4 per cent, of toluene, which at 

 the end of three days was allowed to evaporate by spreading out the soil 

 in a thin layer ; (3) by the same amount of toluene left in the soil during 

 the whole of the experiment. The results are summarised as follows : — 



(1) The increased productiveness of partially sterilised soils is due 

 to an increase in the amount of ammonia present. 



(2) The excess of ammonia is the result of increased decomposition 

 of soil substances by bacteria. 



(3) Hiltner and Stormer's discovery that the bacteria increase 

 rapidly after partial sterilisation, and finally become much more 

 numerous than in the original, untreated soil, is confirmed. The 

 increase in number proceeds pari passu with the increase in ammonia. 



(4) The new bacterial flora arising after partial sterilisation is a 

 more potent decomposing agent than the original flora, but the indi- 

 vidual species have not become more, but apparently less potent. The 

 increased decomposing power of the new flora is associated with its 

 numerical superiority over the old flora. 



(5) The rates of decomposition and of bacterial increase in the 

 toluened soil were found to be adversely affected by the addition of the 

 original untreated soil. The original soil, therefore, contains some 

 factor which limits bacterial action. 



