WATER REQUIREMENT OF DIFFERENT KINDS OF PLANTS. 
77 
From these results it would appear that the water requirements of 
oats, clover, and field peas are about the same. Potatoes and 
barley have a somewhat lower water requirement, and dent corn 
requires about 40 per cent less water than oats for the production of 
an equal amount of dry matter. 
vox seelhorst's experiments. 
Most of the experiments conducted by Von Seelhorst were for the 
purpose of determining the effect of various environmental factors on 
the water requirement. In his experiments, published in 1906 and 
1908, different crops were grown simultaneously under comparable 
conditions, as shown in Table LXIX. The experiments with rye, 
barley, and potatoes were conducted in the large pots described on 
page 68. 
Table LXIX. 
Water requirement of crop plants at Gottingen. Germany, according to 
Von Seelhorst (1906, 1908, and 190s 
Series, date of publication, and 
page reference. 
Crop. Soil type. 
! Wheat Loam. 
Rye do.. 
Potatoes do.. 
iRye I Sand.. 
Barley do.. 
Potatoes.. ...do.. 
{Rye Loam. 
Barley do.. 
Beets do.. 
{Potatoes.. Sand.. 
Rye do.. 
Barlev do.. 
Number 
of deter- 
mina- 
tions. 
Dry 
matter. 
1 
Grams. 
942 
1 
700 
1 
1,173 
2 
364 
1 
457 
3 
3 1,685 
1 
883 
1 
827 
1 
823 
6 
286 
4 
343 
2 
457 
Water 
require- 
ment. 
333 
360 
268 
294 
383 
295 
Period of growth. 
Oct. 8, 1904. to 
Aug. 2, 1905. 
Oct. 8, 1904, to 
Aug. 3, 1905. 
Apr. 26 to Oct. 
10, 1905. 
Aug. 10, 1904, to 
Aug. 2, 1905. 
Mar. 29 to Aug. 
2,1905. 
Apr. 26 to Aug. 
3,1905. 
307 Oct. 17, 1906, to 
Aug. 12, 1907. 
346 Mar. 30 to Aug. 
12, 1907. 
Mav 11 to Nov. 
Si 1907. 
Apr. 24 to Aug. 
7 1907 
Oct. 12,' 1906, to 
Aug. 7. 1907. 
Mar. 30 to Aug. 
7. 1907. 
1 The experiments were mainly conducted in square-meter pots (p. 68). The data in each group are 
comparable, but the different groups can not be intercompared. In the last series half of the determination 
for each crop is from pots that received heavy fertilizer in the fall and half that received light fertilizer in 
the spring. (See Table XLV, p. 74.) Each pot produced a crop of lupine in the late summer and fall of 
1006. The probable error is therefore not given. The second series, rye, barley, and potatoes, grown in 
1905. were all in pots which were given a light application of manure in the spring. 
2 Water requirement based on green weight, 66. 
3 Green weight or based on green weight. 
285 
