WATER REQUIREMENT OF DIFFERENT KINDS OF PLANTS. 
79 
The jars were supported on small cars, which ran on tracks extend- 
ing to the culture house from an inclosure covered with wire netting. 
During the day when the weather was good the jars occupied the 
screened inclosure. At night and during wet weather they were 
brought under cover. 
The jars were weighed each morning, which was accomplished by a 
large beam scale sensitive to 5 grams with a maximum load of 100 
kilograms. By means of a cross track, jars from any track could be 
brought under the balance for weighing. 
Water was added through unglazed earthenware cylinders about 
5 centimeters in diameter and from 15 to 20 centimeters deep, pro- 
vided with small holes in the bottom and the lower part of the sides. 
These cylinders were fixed in position in the center of the jar, so that 
the upper edge coincided approximately with that of the sides of the 
jar. By watering through these cylinders the surface soil remained 
loose, friable, and nearly air-dry, and cracking was avoided. The 
direct loss of water from the soil was also much reduced, being only 
about one-third as much as when the water is added to the surface o 
the soil. The roots were not found to be unusually abundant about 
the cylinders. Clean well water was used for watering the plants. 
Fertilizers, when used, were added either in the dry state to the 
air-dried soil or were dissolved in the water used for dampening the 
soil before filling the pots. The weight of the plants after drying at 
about 100° C. was used in the final calculation of the water require- 
ments. A summary of Leather's results is given in Table LXX. 
Table LXX. — Relative water requirement of crop plants at Pusa, India, baaed on results 
of soils fertilized with N-\-P and N+P+K, according to Leather (1910 and 1911). 
Crop. 
Total 
number 
pots used 
in tests. 
Cold- weather crops: 
Wheat ( Triticum sativum) 
Barley ( Hordeum vulgar e) 
Oats (Avena saliva) 
Linseed (Linum usitatis- 
simum) 
Sarson (kali, Brassica 
campestris) 
Pea {Pisum sativum) 
Gram (chick-pea, Cicer 
arietinum) 
Monsoon crops: 
Maize (Zea mays) 
285 
Mean 
water 
require- 
ment. 
23 
4 
4 
544±10 
468 ±12 
469±40 
6 
807 ±49 
6 
4 
496 ±32 
563±28 
4 
818±77 
31 
337 ± 5 
Crop. 
Monsoon crops — Continued. 
Juar (Andropogon sor- 
ghum) 
Murwa (Ragi millet, Ele- 
usine coracana) 
Kodo (Kodo millet, Pas- 
palu m scrobiculatum) 
Rahar (pigeon-pea, Cajan 
indicum) 
Guar (Cyamopsis psora- 
lioides, C.tetragonoloba). 
Rice (Oryza sativa) 
Sugar cane (Saccharum 
officinarum ) .' 
Total 
number 
pots used 
in tests. 
Mean 
water 
require- 
ment. 
437±41 
263± 2 
312± 4 
635 ±15 
598 ± 5 
811±11 
212± 1 
