WATER REQUIREMENTS IN PLANTS.

Lyttelton Times, Volume CXV, Issue 16493, 7 March 1914, Page 6

WATER REQUIREMENTS IN PLANTS.

(By W. C. PALMER, Agricultural Editor, North Dakota Agricultural College.)

Different crops require different amounts of water. These amounts also vary for each crop under different climatic conditions. A knowledge of these water, requirements of the different crops may in a measure serve as a guide in selecting the ones best adapted to certain sections. Briggs md Shantz, of the Bureau of Plant Industry, Wellington, D.C., have carried on investigations in the water requirements of different crops at Akron, Colo,, and at Amarillo and Dalhavt, Texas, in 1910 and 1911. The results of these experiments are given in Bulletin No. 284, Bureau of Plant Industry. The average of these experiments are as follows:—Pounds water required to produce a pound of dry matter (whole plant)—millet 275, sorghum 306, pig weed 275, tumble weed 277, Russian thistle 336, corn 369, sugar beet 377, rape 441, potatoes 448, wheat 507, barley 539, buckwheat 578, oats 614, sweet clover 709, field peas 800, lucerne 1068. The pounds water required to produce a pound of grain was as fellows:—Sorghum 790, millet 923, buckwheat 1037, barley 1244, wheat 1357, oats 1680. It required 166 pounds of water to produce a pound of potato tuber and 110 to produce a pound of sugar beet root. This brings out the big difference, between tho effective use that the different crops can make cf the moisture. .It does not, however, take into consideration the ability of the different crops to secure moisture through their larger or small root systems. Tho water , requirement of the legumes aud especially lueerue is high. It must be kept in mind though that the legumes are high in protein. The water that would suffice for producing a 50 bushel crop of oats, according to these figures, should be sufficient for producing 2ooolb of lucerne. 4he f>o bushel oats will contain 1711 b digestible protein, while the 25001 b of lucerne will contain 2771 b digestible protein. Of digestible carbohydrates and fat the 50 bushels oats contain 9421 b, while the 25001 b lucerne would have 10121 b. The lucerne with its larger root system, and especially if the plants are not too thick, will be able to draw moisture from more soil than can the oat plant, and will therefore be able to produce more than the 25001 b of lucerne to the 50 bushels of oats. In fact it will likely be nearer two tons, which would contain 4441 b digestible protein and 16201 b of digestible fat and carbohydrates. It was also found that the different varieties of a crop required different amounts of water, as for instoouCe the following varieties of wheat (.whole plant, pounds water to make one pound dry matter): Kubanka 468, Galgalgoa 496, Spring Ghirka 506, Marvel Blue Stein 531. Pounds water te produce one pound grain Kubanka 1191, Galgalgoa 1245, Spring Ghirka 1382/ Marvel Blue Stem 1786.

This data helps to explain why corn, millet and kaffir have done better than some other crops in the regions of lighter rainfall.