Agronomy and Horticulture Department


Date of this Version



Published in Ecology, Vol. 16, No. 4 (Oct., 1935), pp. 612-629. Copyright 1935 Ecological Society of America. Used by permission.


Drought during the growing season of 1934 was the greatest ever recorded in the prairie region. It offered an exceptional opportunity to study the response of native plants to extremely adverse water relations. Measurements of the environmental factors of the prairie, in connection with various grassland researches, have now been completed, except for one year, for the seventeenth consecutive growing season. In a summary of findings at the end of twelve years it was stated that although periods of drought are liable to occur at any time, and especially after midsummer, yet only twice during these twelve years was the water content in the surface six inches of soil reduced to the hygroscopic coefficient, i.c. approximately the point where water is non-availahle for growth (Weaver aid Himmel, '31). At no time was the available water in the deeper soil entirely exhausted. Drought periods when water was nonavailable in the surface foot occurred during 1931 and 1933 (Flory, '34). Then came the extremely dry summer of 1934 during which the prairie was under the impact of almost continuous drought. These studies were made near Lincoln, Nebraska, hut similar conditions prevailed, in general, throughout the tall-grass prairie in the eastern one-third of the state, except in the extreme northeastern part.