226 HOW CROPS GROW. 



On dividing the above quantities by the number of days 

 of the respective periods, there results: 



The Average Daily Gain or Loss per Acre during 

 each Period. 



TABLE IV.Bretschneider. 



Dry Matter. Water. 



1st Period, 22 Ibs. Gain. 87 Ibs. Gain. 

 2d & 3d " 163 " 377 " " 



4th " 52 " " 134 " Loss. 



5th " 162 " " 646 " 



4. Table III., and especially Table IV, show that the 

 gain of organic matter in Bretschneider's oat-crop went 

 on most rapidly at or before the time of blossom (accord- 

 ing to Arendt at the time of heading out). This was, then, 

 the period of most active growth. Afterward the rate of 

 growth diminished by more than one-half, and at a later 

 period increased again, though not to the maximum. 



Absolute Quantities of Carbon, Hydrogen, Oxy- 

 gen, Nitrogen (Organic Matter), and Ash in the dry 

 oat-crop at the conclusion of the several periods (Ibs. 

 per acre) : 



TABLE V.Sretschneider. 



Carbon. Hydrogen. Oxygen. Nitrogen. Ash.* 



1st Period, 593 80 455 46 110 



2d & 3d " 2,137 286 1,575 122 263 



4th " 2,600 343 2,043 150 291 



5th " 3,229 405 2,713 167 372 



Amounts of Carbon, Hydrogen, Oxygen, Nitro- 

 gen, and Ash-ingredients assimilated by the oat-crop 

 during the several periods. Water of vegetation is not 

 included (Ibs. per acre) : 



TABLE VI.Bretschneider. 



Nitrogen. AtMngredients. 

 46 110 



76 153 



28 28 



17 81 



* In Bretschneider's analyses, " ash " signifies the residue left after 

 carefully burning the plant. In Arendrs investigation the sulphur 

 and chlorine were determined in the unburned plant. 



