214 HOW CROPS FEED. 
ing. Ritthausen gives some data concerning two clover 
crops of the year 1854, from a loamy sand, portions of 
which were manured, one with ashes, others with gypsum. 
The following statement gives the produce of the nearly* 
fresh and of the air-dry crops. 
Weight in pounds per acre. 
Fresh, Air-dry. Water lost in drying. 
Crop I, manured with ashes, 14,903 5,182 9,721 
“* * anmanured, 12,380 5,418 6,962 
Crop II, manured with gypsum, 22,256 4,800 17,456 
“ef unmanured, 18,815 5,190 13,625 
It is seen that while in both cases the fresh manured 
crop greatly outweighed the unmanured, the excess of 
weight consisted of water. In fact, the unmanured plots 
yielded more hay than the manured. The manured clover 
was darker in color than the other, and the stems were 
large and hollow, i. e., by rapid growth the pith cells were 
broken away from each other and formed only a lining 
to the stalk, while in the unmanured clover the pith re- 
mained undisturbed, the stems being more compact in 
structure. (H. C. G., p. 369.) 
The Quantity of Soil-water most favorable to Crops 
has been studied by Ilienkoff and Hellriegel. The former 
(Ann. der. Chem. u. Ph. 136, p. 160,) experimented with 
buckwheat plants stationed in pots filled with garden 
earth. The pots were of the same size and had the same 
exposure at the south side of an apartment. The plants 
received at each watering in 
Pot No. 1, *|, liter of water 
“ (7) 1 ls 173 cc 
(73 cc 1 le “ cc 
oc (73 
(73 (t4 5 1 | “ (74 
? 32 
(79 (<4 
PR 99 20 
* The clover was collected from the surface of a Saxon square ell, and was 
somewhat wilted before coming into Ritthausen’s hands. The quantities above 
given are calculated to English acres and pounds, 
