UNITED STATES DEPARTMENT OF AGRICULTURE 



DEPARTMENT BULLETIN NO. 1379 



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Washington, D. C 



January, 19& 



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ELECTROCULTURE 



By Lyman J. Briggs, 1 A. B. Campbell, R. H. Heald, and L. H. Flint, Office 

 of Biophysical Investigations, Bureau of Plant Industry 



CONTENTS 



Page 



Normal electrical state of the atmosphere . 1 



Electrical field employed in electrocultural 



experiments 2 



Electrocultural experiments with miscel- 

 laneous crops 3 



Electrocultural field experiments with grains. 4 

 Electrocultural experiments in the plant 



house 13 



Page 

 Summary of experiments at Arlington Ex- 

 periment Farm 15 



Review of other investigations in electrocul- 



ture 17 



Experiments with soil currents 17 



Experiments with modified potential 



gradients 21 



Literature cited 32 



The term "electroculture" as used in this bulletin refers to practices 

 designed to increase the growth and yield of crops through electrical 

 treatment, such as the maintenance of an electric charge on a net- 

 work over the plants or an electric current through the soil in 

 which the plants are growing. 



During the past 75 years many experiments in electroculture have 

 been carried out with varying degrees of refinement. Some of these 

 experiments indicate that the yield of crops can be materially in- 

 creased by electrical treatment. Others, conducted along similar 

 lines, fail to show any marked response to the treatment. In this 

 latter class are included the experiments conducted by the Office of 

 Biophysical Investigations of the Bureau of Plant Industry, which 

 are reported in the following pages. This report is followed by a 

 brief account of other investigations in this field. Investigations 

 relating to the cultivation of plants under electric lights are not in- 

 cluded in the review of the literature of electroculture, the response 

 of the plants under such conditions being due primarily to the heat 

 and light into which the electrical energy has been transformed. 



NORMAL ELECTRICAL STATE OF THE ATMOSPHERE 



Since the effect of using a charged network over growing plants is 

 to change the electrical state of the atmosphere surrounding the plants 

 it seems desirable to discuss briefly the normal electrical conditions in 

 the atmosphere and the changes produced by the charged network. 

 An examination of the electrical conditions in the atmosphere oyer 

 an open field on a clear day shows that there is a force tending to 

 move a positively charged body downward; in other words, the 

 electrical field of force is identical with that which would exist if the 

 earth were charged negatively. 



i Physicist, Bureau of Standards, since 1920. 

 62149°— 26f 1 



