1 Revised manuscript received Sept. 9, 1963. 2 Paper 37, Plant Nutrition Laboratory. This work was supported by research grant RG-07339-02 from the National Institutes of Health. :'Present address: Division of Agricultural Developnihnt, Tennessee Valley Authority, VVilson Dam, Alabama. specified (8). In some cases it is known that a, mixture of molecular species may be present, and often the ma...

Magnesium contents of soybean (Glycine max) roots increase and the K and Ca contents decrease with increased MgCl(2) concentrations in ambient solutions. The Mg uptake is inhibited when both Ca and K are present in the solution, but not by K or Ca alone. Chloride uptake, which is very low from the MgCl(2) solution, is greatly enhanced by the presence of K. The selectivity against Mg imparted by...

The cultivatioo of narrow·leafed lupins (Lupinus angustifolius L) increases rates of subsoil acidification, and this is thought to be partly related to their pattern of nutrient uptake and H+ jOHexcretion. The main hypothesis of this study was that H+ and OHexcretion is not distributed evenly over the entire length of the root system but is limited to zones where excess cation or anion uptake o...

Potassium in plants accounts for up to 10% dry weight, and participates in different physiological processes. Under drought stress, plant requires more potassium but potassium availability in soil solutes is lowered by decreased soil water content. Forming symbiosis with arbuscular mycorrhizal (AM) fungi not only enlarges exploration range of plant for mineral nutrients and water in soil, but a...

Sickle erythrocytes (RBC) incubated under 100% nitrogen for 4 hr manifested marked Na gain with an equivalent K loss. There were no changes in cell total cation or water content under these conditions, and no irreversible sickle cells (ISC) were formed. In contrast, sickle RBC incubated for 24 hr under 100% nitrogen in a glucose-free Na medium containing calcium manifested marked ISC formation....

Previous publications have described a "volume controlling mechanism" in duck erythrocytes that returns both enlarged and shrunken cells to their original isotonic volume. Enlarged cells return to their original size by readjusting their K content. To study the specificity of this aspect of the mechanism for K, we prepared enlarged cells with various Na and K contents. Only cells containing a h...

Details about the spatiotemporal development of root systems and their influence on ring-width variations in tree stems are still unknown. Furthermore, their size, spread and architecture play an important role in studying tree stability and their stabilizing effect on slopes. A major problem in this regard is the detailed 3D-data acquisition and modeling of its complex structure. The appli cat...