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Temperature Effect on Potassium Uptake and Respiration by Warm and Cool Season Grasses and Legumes
Author(s) -
Worley Ray E.,
Blaser R. E.,
Thomas G. W.
Publication year - 1963
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1963.0011183x000300010006x
Subject(s) - tifton , potash , library science , agricultural experiment station , agronomy , horticulture , biology , forage , computer science , fertilizer , agriculture , ecology
Ray E. Worley, R. E. Blaser, and G. W. Thomas DIFFERENTIAL potassium uptake by plant species has been a subject for study for many years. Blaser and Brady (1) found that grasses absorb more potassium than legumes and that grasses crowd out the associated legumes when available soil potassium is low. The differential potassium uptake by plant species has been attributed to the different cation exchange capacities of plant roots (5). Such cation exchange theories might be important in moving cations to the root surface, but recent work by Epstein (4) and others, with respect to metabolically-produced ion specific carriers, indicates that movement of cations to the inside of the cells involves a more complex physiological process than cation exchange. Respiration is necessary for production and turnover of the ion carrier and for maintenance of ions in the tissue once they have been absorbed. The respiration rate is governed by temperature and other factors. It might be postulated that plants which grow at low temperatures would take up more potassium at low temperatures than plants with high optimum growth temperatures. If this postulation were true, it might explain why pasture grasses of northern origin start growth at lower temperatures than associated legumes. Because of this earlier physiological activity, the grasses may deplete the soil of potassium before legumes start growth. If root cation exchange capacity is important, grasses would take up considerably more potassium than legumes regardless of the temperature, provided the change in temperature did not change the cation exchange capacity of the root. This paper gives data on the comparative rate of potassium uptake by a warm-season grass, a cool-season grass, and warm and cool-season legumes at various temperatures. Since respiration is necessary for ion uptake and maintenance of ions in the tissues, CO., release was measured simultaneously with potassium uptake.