Contents 



Page 

 Illustration; New Laboratory 2 



Experimental Station Staff 4 



Introduction 5 



Report of the Three Years' Work, 1915-17 7 



The Library 15 



Report on Farm and Experimental Plots: Season 1914 15, 



1913-16, 1916-17 15 



Papers published : 



Soil Problems: AtiiKJsphere of the Soil - Biochemical 

 Clianges in the Soil Dissohed Oxygen in Rainwater — Soil 

 Protozoa — Organic Residues and Nitrogen Fixation — Bacterio- 

 Toxins in Soil — Dilute Acids and Phosphorus Compounds of 

 the Soil — Adsorption by Soil — Loss of Phosphoric Acid dur- 

 ing fusion with Ammonium Chloride — Lime requirements of 

 Soils— Soluble Humus and Soil Productiveness ... ... 22 



Farmyard Manure : Making and Storing of Farmyard 

 Manure — Fixation of Nitrogen in F.rces — House Flies and 

 Manure Heaps ... ... ... ... ... ... ... 28 



Plant Nutrition Problems : Formation and Translocation 

 of Carbohydrates in Plants — Enzymes in Carbohydrate Analy- 

 sis — Organic Plant Poisons — Concentration oi Nutrient Solu- 

 tion and Plant Growth — Recolonisation of Land gone out of 

 Cultivation — Effect of Weeds upon Cereal Crops — Buried 

 Weed Seeds 31 



Technical Papers: West Country Grasslands — Weeds on 

 Arable Land — Yield of Second-rate Arable and Pasture Land 

 — Crops without Potash Manure — Two White Straw Crops 

 in Succession— Loss of Nitrate from Arable Soils — Soil An- 

 alysis — Increased Crop Production — Chalking — Army Stable 

 Manure — Humogen — ^Dried and Degreased Sewage Sludge — 

 Charcoal and Plant Growth ... ... ... ... ... 40 



Papers Summarising Recent Progress in Agricul- 

 tural Investigations 48 



Books Published 48 



Enquir'es Undertaken at Government Request 49 



Tables of Field Trials, etc 51 



Trustees and Committee of Management 70 



Members of Council of the Incorporated Society for Ex- 

 tending the Rothamsted Experiments in Agricultural 

 Science 70 



Subscribers and Donors 71 



