40 
WATER REQUIREMENT OF PLANTS. 
urements made with potatoes, tobacco, buckwheat, mustard, chicory, 
and oats. 
Table XXX. — Effect of different amounts of potash on the water requirement of crops, 
according to Wilfarth and Wimmer (1902, pp. 10-15). 
Fertilizer per pot. 
Mean 
Mean 
Crop and period. 
Soil, etc., per pot. 
dry mat- 
ter. 
water 
require- 
K 2 0. 
N. 
ment. 
Grams. 
Grams. 
Grams. 
1. 400 
1.400 
20.1 
28.7 
717±3 
Potatoes: l 
1897 
""'6.*094' 
504 ±27 
Sand and turf 
.188 
.940 
1.400 
2.388 
36.7 
76.9 
422 ±11 
291±4 
1. 504 
2.388 
102.8 
254±2 
Apr. 29 to Sept. 8, 1897 2 
fSand, 3,760 grams; turf, 240 
\ grams; water, 1,000 grams. 
f .188 
1. 504 
[ 4. 700 
1.680 
2.380 
2.800 
35.0 
99.2 
114.0 
453 ±15 
257 ±5 
230 ±15 
------ 
2.450 
39.8 
637 ±30 
2.450 
45.6 
598 ±5 
May 2 to Sept. 13, 1898 3 
fSand, 6,670 grams; turf, 455 
\ grams; water, 1,800 grams. 
.282 
.282 
2.450 
3.920 
56.4 
65.3 
528 ±49 
507 ±32 
.846 
3.920 
100.3 
396±12 
I 1. 692 
3.920 
128.3 
339 ±7 
1.120 
33.8 
1,345 ±55 
"'"'.'282' 
1.120 
50.5 
878 ±72 
fSand, 6,670 grams; turf, 455 
J grams; water, 1,800 grams; 
| water increased Aug. 24 
2.800 
2.800 
50.3 
82.8 
502 ±76 
283 ±4 
May 5 to Sept. 13, 1899 3 
""."282" 
l" to 2,010 grams. 
.846 
2.800 
121.5 
267 ±10 
1.800 
2.800 
165.1 
198 ±5 
4.700 
2.800 
176.4 
260 ±2 
[Sand, 6,670 grams; turf, 455 
grams; water, 1,780 grams; 
3.290 
2.940 
199.3 
232 ±6 
Apr. 25 to Sept. 15, 1900 3 . . 
\ water increased Julv 5 to 
I 6. 580 
2.940 
214.4 
*214±2 
2,250, and July 18 to 2,375 
9.400 
2.940 
188.8 
235 ±14 
( grams. 
f . 0235 
1.400 
17.0 
909 ±41 
Tobacco: 5 
.094 
1.400 
23.7 
749 ±5 
Apr. G to Aug. 20, 1897 6 
/Sand, 3,760 grams; turf, 240 
\ grams; water, 1,000 grams. 
.940 
1. 410 
2.380 
2.380 
65.7 
83.9 
446 ±19 
372 ±2 
[ 2.585 
2.380 
75. 7 
i 403±5 
.0235 
2.030 
14.4 
893 ±13 
.094 
2.030 
22.1 
626 ±0 
.188 
2.030 
26.8 
665 ±30 
Apr. 21 to Sept. 17, 1898 8 
/Sand, 4,445 grams; turf, 305 
\ grams; water, 1,200 grams. 
.188 
3.500 
29.3 
556±12 
.564 
3.500 
52.7 
443±4 
2.115 
3.500 
87.0 
419 
2. 820 
3.500 
83.2 
434 
[ . 0235 
1.120 
20.3 
696±3 
.282 
1.120 
52.4 
457 ±28 
fSand, 4,445 grams; turf, 305 
Apr. 24 to Oct. 5,9 1899 8 
J grams; water, 1,200 grams; 
1 water increased July 13 to 
.0235 
.282 
2.520 
2.520 
29.4 
55.4 
422 ±23 
382 ±24 
( 1,370 grams. 
.846 
2.520 
85.2 
300±11 
1.880 
2.520 
84.5 
297 ±5 
2.820 
2.520 
93.3 
273 ±2 
1 Computed from data of Wilfarth and Wimmer (1902, pp. 10-15). Duplicate determinations were made 
except where probable error is not given, in which case only one determination was made. (See Wilfarth 
and Wimmer, 1902, pp. 8-9, form A, for a complete record of the fertilizers used with potatoes.) Tops, 
tubers, and roots are included. On page 13, in columns 17 and 18, are errors. 
2 Miihlauser variety used. 
3 Geheimrat Thiel variety used. 
4 Mean of eight determinations. 
6 Computed from data of Wilfarth and Wimmer (1902, pp. 44-51). Duplicate determinations were made 
except where no probable error is given, in which case only one determination was made. The dry matter 
includes roots. (See Wilfarth and Wimmer, 1902, pp. 34-35, form B, for a complete record of the fertilizers 
used with tobacco.) 
6 Nicotiana rustica variety used. 
7 Ten determinations. 
8 Nicotiana tabacum (Virginia) variety used. 
9 Thehjaves were harvested at different times and the flower buds cut off. 
285 
