244 



Journal of Agricultural Research 



Vol. XIX, No. 6 



readily be shown and offset by the frequency with which the analyses 

 were made. 



The greensands, soil, and manure used were analyzed at the beginning 

 of the investigation. The results are given in Table I. The potassium 

 determinations were made by the official fusion method. 



Table I. — Composition of materials used (dry basis) 



o Loss on ignition, 69.67 per cent. 



Determinations made by the Veitch method showed that the New 

 Jersey greensand required 4,200 pounds of calcium carbonate per 

 2,000,000 pounds, the Maryland greensand 3,400 pounds, and the 

 CoUington sandy loam i ,400 pounds. 



The texture of the greensands and soil is shown in Table II, which 

 gives the mechanical analyses of the materials used in the composts. 



Table II. — Mechanical analyses of greensands and soil 



Constants. 



Fine gravel . . 

 Coarse sand . . . 



Fine sand 



Very fine sand 

 Silt and clay. . 



New Jersey 

 greensand 



Per cent. 



4. 94 



30. 26 



45.22 



IS- 14 



4. II 



Maryland 

 greensand. 



Per cent. 

 1.49 

 1.77 



9- 15 



83-65 



3-86 



CoUington 

 sandy loam. 



Per cent. 



0-S3 

 10. 14 

 26. 27 



43-93 

 18. 72 



PRESENTATION AND DISCUSSION OF RESULTS 

 ACIDITY 



In Table III is shown the acidity of the water extract from each com- 

 post as determined at the end of each i -week period for the first 9 weeks 

 and thereafter at the end of each 3 weeks for a total period of 23 weeks. 

 The results are expressed in terms of Nlio sodium hydroxid required to 

 neutralize the acidity in the water extract from lo-gm. of compost on 

 the dry basis. 



