llf> 



RELATION OF "WATER TO CROPS. 



E. A\V)llny has studied the rehitioii of the irrigation and rainfall to 

 the development and productive poAver of plants in cultivated fields, 

 and the following sununarv is essentially as given by him in Volume 

 X of his Forschungen for 1888, page 153. 



An early investigation of this subject was made by Ilionkotf, who 

 filled five large tubs with soil and sowed buckwheat in each on the 

 loth of May; each tub was then watered regularly with a definite 

 quantity of water, the total quantity used being given in the second 

 column of the table following. The relative quantities of buckwheat 

 harvested at the end of the season are given in the third column and 

 the straAv is given in the fourth column. The weight of the buck- 

 wheat originally sown in each tub was the same, viz, 0.154 gram. 



Total 

 water 



ap- 

 plied. 



Weight of green har- 

 vest. 



Grain.! Straw, 



Sum 

 total. 



Weight of dry „ 

 harvest. Num- 

 ber 

 of ker- 

 I nels 

 Grain. Straw. I har- 

 i vested. 



Ratio 



of 



straw 



and 



kernels 



to the 



seed. 



2 



3 

 4 



Liters 

 25.00 

 12.50 

 6.25 

 3.12 

 1.56 



6.15 

 1.95 

 .58 

 .10 



Grams. 

 26.10 

 58.85 

 23.03 

 9.42 

 2.20 



Grams, 

 27.99 

 65.00 

 24.98 

 10.00 

 2.30 



Grams. Grams. 



1.68 

 5.47 

 1.73 

 .52 

 .09 



4.52 

 8.47 

 4.55 

 1.41 

 .30 



These figures show plainly that the plants in tub No. 2 were most 

 favorably situated. Probably No. 1 had too much water and Nos. 3, 

 4, and 5 too little. 



Haberlandt, in 18G(), experimented on the quantity of water needed 

 in the growth of plants in three plats of 14.41 square meters each; 

 of these No. 1 received no artificial watering; No. 2 was watered once 

 a w^eek, except in great droughts tAvice a week; No. 3 received a 

 double quantity once a week. These quantities corresponded to a 

 rainfall of 6.46 millimeters for No. 2 and 13.92 millimeters for No. 3. 

 The total quantities for the season Avere 96.96 and 193.92 millimeters. 

 The natural rainfall Avas as follows: 



K^y^ Rainfall. 



March 17 i 



April 15 ! 



May 11 I 



June - 13 I 



July. _. 17 i 



Total 73 I 



mm. 

 40.98 

 35.38 

 52.20 

 46.03 

 34.40 



208.99 



