1905.] 



On the Retention of Bases by the Soil. 



5 



The samples, after drying at a temperature not exceeding 60° C, are roughly 

 powdered and put through a woven wire sieve with a mesh of £ inch (this 

 sieve passes a little more than the 3 mm. round-hole sieve now commonly 

 used). From the fine earth thus obtained from each hole composite samples 

 representing the whole plot at each depth are then made up, of which portions 

 are finely ground for analysis. 



Table I gives details of the manurial treatment of the various plots in 

 Broadbalk and Hoos Fields, in the soil of which the calcium carbonate bas 



Table I. — Nature and Quantities per Acre of the Manures annually applied * 



* 

 s 



Date of 

 beginning 

 treatment. 



Farmyard 

 manure. 



Sodium 

 nitrate. 



Ammonium 

 sulphate. 



Ammonium 

 chloride. 



Eape cake. 



Super- 

 phosphate. 



Potassium 

 sulphate. 



Sodium 

 sulphate. 



Magnesium 

 sulphate. 



Broadbalk Field. 







tons. 



lbs. 



lbs. 



lbs. 



lbs. 



cwts. 



lbs. 



lbs. 



lbs. 



3 



1844 



Unmanured 



















2b 



1844 



14 



















5 



1852 













3 5 



200 



100 



100 



6 



1852 







100 



100 





3 5 



200 



100 



100 



7 



1852 







200 



200 





3-5 



200 



100 



100 



8 



1852 







300 



300 





3 5 



200 



100 



100 



y 



1852 





275f 









3 5 



200 



100 



100 



10 



1845 







200 



200 













11 



1849 







200 



200 





3 5 









Hoos Field. 



10 



1852 



Unmanured 



















4o 



1852 













3 5 



200 



100 



100 



lA 



1852 







100 



100 













4a 



1852 







100 



100 





3-5 



200 



100 



100 



In 



1868 





275 

















4n 



1868 





275 









3-5 



200 



100 



100 



lc 



1852 











1000 











7-2 



1852 



14 



















* For certain minor variations in the amounts of manure applied see " Memoranda of the Field 

 and other Experiments at Eothamsted. Lawes Agricultural Trust, 1901." 

 t 550 lbs. per annum up to 1884. 



been determined ; Table II gives the average weight in pounds per acre of the 

 fine dry soil in the layer 9 inches deep which is removed by the sampling 

 tool for the different fields at each of the specified dates ; Table III for 

 Broadbalk, Table V for Hoos, and Table VII for Agdell and Little Hoos Fields 

 give the percentages of calcium carbonate in the fine soils dried at 100° C. 



