Suluhlc Constituents in Alluvial Soil. 49 



prnnmiiKcd. and the slijrlit increase in the average >ho\vs that 

 the snlvtMit actions in the soil more than hahmced the loss by 

 drainatre and by the crop. 



May is 



Plot 3— Star Pliosphate Surface O.'j!) 



(4cwt. per acre) 8 inches 0.34 



1() inches 0.48 



Averao^e 0.47 



The manure beintr only sparingly soluble, the steady decrease 

 of the averages probably represents soil constituents previously 

 present. These show the usual drop after rain in the surface 

 layer, and no absolute, but only a relative increase or lessened 

 decrease on the surface after dry weather. 



May 18 



Plot 5 — Done Dust Surface 0.51 



(4cwt. per acre) 8 inches 50 



16 inches 0.63 



Avera<^e 0.55 



This resembles the preceding closely, except thart the concen- 

 tration on the surface in December is better showTi. Both cases 

 indicate an exhaustion of the soluble soil constituents by the 

 crop or by drainage, for if the manures fixed or precipitated 

 the soluble constituents, the first surface ei?timation in May 

 would be a low instead of a high one. 



May 18 



Plot 8 — Calcium Superpliosi^hate Surface 0.54 



(2cwt. per acre) 8 inches 0.57 



16 inches 0.56 



Average 0.55 



Although the manure is highly soluble, and the amount of it 

 not too small (0.28 gram per kilogi'am of upper 2 inches when 

 first applied), it does not seom to produce any pronounced direct 

 effect upon the changers in the distribution of the soluble matter 

 in the sdil. which resemble those in the pi'eceding plot. 



The blood manure apparently exercises an important indirect 

 action on the soil, increasintr the iwnount of soluble matter 



