33 



activities. Food stuffs (especially nitrogen compounds and 

 phosphates) are supplied, along- with calcium carbonate to obviate 

 acidity, and decomposition then proceeds rapidly, converting 

 waste useless straw and other materials into valuable manure. 



The large scale development is carried out by the non-profit 

 making- " Adco M syndicate, of which Lord Elveden is Chairman, 

 thus relieving the Station of much exploitation work for which 

 it is not suited. The numerous scientific problems constantly 

 arising out of the field experience are studied by Messrs. E. H. 

 Richards and R. L. Amoore in these laboratories. 



The organisms are naturally present in the straw or in the 

 dust and they need not be deliberately added. It is, however, 

 important to discover exactly what they use, how they 

 do their work, and what conditions are necessary to their 

 efficiency. These problems are studied in the Bacteriological 

 Department. A new organism has recently been found by Mr. 

 P. H. H. Gray, which not only decomposes cellulose rapidly, but 

 unlike the Spirochceta CytopJiaga previously isolated in the 

 laboratory, acts in presence of sugar and is indeed stimulated by 

 small quantities of xylose and lignin such as occur in straw. 

 It seems probable that this new organism plays a considerable 

 part in the decomposition of straw in practice, in the making 

 of farmyard manure and other important changes. 



PARTIAL STERILISATION AND CONTROL OF SOIL. 

 PESTS AND DISEASE ORGANISMS. 



These are conveniently dealt with together. The methods 

 first tested in these laboratories 17 years ago involved either heat- 

 ing the soil or treatment with volatile antiseptics such as toluene 

 and carbon disulphide. The first applications were made in glass 

 houses, and the method first used in practice was heat. This 

 is effective but costly, and it cannot be much cheapened. 

 Chemicals offer much better prospects and search is being made 

 in Mr. Tattersfield's Department for agents which will effect the 

 same purpose as heat at less cost. The obvious method of 

 utilising industrial waste products is less useful than might be 

 expected owing to their variable composition : the first invest- 

 igation is, therefore, directed to the discovery of the organisms 

 to be put out of action and the testing of chemical compounds 

 in a definite systematic manner, so as to obtain information as 

 to the relationships between chemical constitution and effective- 

 ness. The proper quantity and the suitable time and method 

 of application have all to be determined by direct trial, while 

 laboratory experiments are made to discover more particularly 

 the precise actions going on. The most interesting result thus 

 far obtained is that organic substances, such as the cresols, phenol 

 and cresol derivatives, and the chlornitro derivatives, such as 

 chlorpicrin and chlordinitrobenzene, can, when applied to soil in 

 proper quantity, determine substantial crop increases, though it 

 is not yet known how far the effect is due to removal of disease 

 organisms, and how far to improvement in nitrate production or 

 to direct stimulation of the plant. Under this treatment tomatoes 



