6 CONTENTS. 
Effect of soil factors on the water requirement — Continued. 
Effect of fertilizers on the water requirement— Continued. 
Soil cultures — Continued. Page. 
Liebscher's experiments 35 
Maercker's experiments 36 
Schroeder's experiments : 37 
Von Seelhorst's experiments 37 
Wilms's experiments 38 
Daszewski's experiments 39 
Wilfarth and Wimmer's experiments 39 
Von Seelhorst and Biinger's experiments 44 
Ohlmer's experiments 44 
Preul's experiments 45 
Summary of experiments at Gottingen, Germany 45 
Wimmer's experiments 46 
Widtsoe's experiments 49 
Kiesselbach's experiments 50 
Leather's experiments 50 
Von Seelhorst's later experiments 52 
Montgomery and Kiesselbach's experiments 53 
Pfeiffer, Blanck, and Flugel's experiments 53 
Conclusions 53 
Water cultures 54 
Woodward 's experiments 54 
Sorauer's experiments 55 
Heinrich's experiments 55 
Conclusion 56 
Effect of a previous crop on the water requirement 56 
Von Seelhorst's experiments 56 
Effect of soil temperature on the water requirement 57 
King's experiments 57 
Leather's experiments 57 
Conclusions 58 
Effect of climatic factors on the water requirement 58 
Effect of different atmospheric conditions on the water requirement 58 
Fittbogen's experiments 58 
Hellriegel's experiments 59 
King's experiments 60 
Von Seelhorst's experiments 60 
Briggs and Shantz's experiments 60 
Conclusions 61 
Effect of air temperature on the water requirement 61 
Effect of shade on the water requirement 61 
Sorauer's experiments 62 
Hellriegel's experiments 62 
Pfeiffer, Blanck, and Flugel's experiments 63 
Conclusions 63 
Effect of air humidity on the water requirement 63 
Sorauer's experiments 63 
Heinrich's experiments 63 
Montgomery and Kiesselbach's experiments 64 
Conclusions 65 
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