14 



REPORT FOR THE YEARS 1923-24 



The purpose of the work at Rothamsted is to discover the 

 principles underlying the great facts of agriculture, and to put 

 the knowledge thus gained into a form in which it can be used 

 by teachers, experts and fanners for the upraising of country 

 life, and the improvement of the standard of farming. The 

 criterion by which the work is to be judged is its trustworthiness; 

 if it satisfies this condition it will assuredly find its place in 

 farm practice, or as part of the material which teachers can use 

 in country schools, farm institutes and agricultural colleges for 

 the education of their pupils. 



The most fundamental part of agriculture is the production 

 of crops, and to this subject most of the Rothamsted work is 

 devoted. The problems fall into three groups concerned respec- 

 tively with the cultivation of the soil, the feeding of the plant 

 and the maintenance of healthy conditions of plant growth. 



The field work at Rothamsted for many years centred round 

 the effects of artificial manures and of farmyard manure in the 

 production of farm crops. The farmers of Great Britain make some 

 £14,000,000 worth of farmyard manure each year, and they spend 

 on artificial manures a sum which is probably not much short 

 of £8.000,000 a year. The waste of farmyard manure is known 

 to be considerable, and it is certain that the artificials are not 

 used as well as they could be. Numerous measurements indicate 

 that only about 60 or 70 per cent, of the nitrogen given in arti- 

 ficial fertilisers is recovered in the crop ; the remaining 30 or 

 40 per cent, is wasted. It has been estimated that the loss from 

 wastage of farmyard manure and of artificials in the soil represents 

 a sum probably not less than some £8,000,000 or £9,000,000 per 

 annum. 



The Rothamsted plots, while demonstrating the effects 

 of the various artificial fertilisers on farm crops, are not 

 in themselves sufficient to afford guidance as to the most 

 suitable kind of manuring for any particular crop or soil type. 

 The influence of soil and season on the effectiveness of manures 

 is very considerable but until recently it has not been studied 

 in detail : a beginning has now been made. Two methods of 

 investigation are followed : In one, the analytical method, the 

 Rothamsted data, which now extend over periods varying from 

 60 to 80 years, are being examined by statistical methods so as 

 to show the effect of climatic elements, rainfall, sunshine, etc., 

 on yields. The other is the observational method, intended to 

 elicit the basic facts which can then be further studied in the 

 laboratory. It is pursued in several ways. The Rothamsted plots 



