Calcium and Soil-Borne Nutrients
CALCIUM PLAYS WHAT might be termed the leadership role amongst the nutrient ions not only as to their entrance into the plants but also as to their combination into the proteinaceous compounds around which cell multiplication and life itself center.
As the protein concentration of forages rises, there is also an increase in the calcium concentration. Also there is accumulation of evidence that with the increase in protein there goes an increase in vitamins.
Legume demand
Legumes, the more nutritious of the forages, have long been known for their demand for calcium and high content of protein. They are also high in other minerals, so that calcium in the plants seems to synthesize the soil-borne nutrients into the organic combinations though it does not itself appear as part of the final products.
Potassium, quite unlike calcium, is more directly effective in the compounding of air and water into carbohydrates, and like calcium does not itself appear in them. Potassium is effective in making bulk or tonnage, of forage.
Potent proteins
Calcium is effective in bringing higher concentration of proteins, and other essential nutrients within that bulk. According as the active calcium dominates the supplies of nutrients in the soil, so proteinaceousness—and with it a high content of growth minerals—characterize the vegetation produced on the soil.
As potassium dominates, there is plenty of plant bulk but its composition is highly carbonaceous or it is dominantly woody.
Ecological array
Here is a general principle that is helpful in understanding the ecological array of vegetation. According to it, the vegetation is highly proteinaceous and mineral-rich on our prairies in the soil regions of lower rainfall or those retaining a high mineral content with calcium prominent. Contrariwise, vegetation is mainly wood, or like the forest, on the more leached soils with lower mineral content but with potassium naturally dominant.
Soil studies
This ecological picture served as a stimulus for some soil studies of the chemical activities of potassium and calcium when present on the clay in different ratios.
Prof. C. E. Marshall of the University of Missouri, has designed electrodes and membranes for measuring the ionic activity of calcium and potassium in the same way as hydrogen ion activities are measured.
Conclusions
His studies demonstrate clearly that the ionic activities in a mixture of elements are not independent of each other, as is true in mixtures of gases. Rather they are complimentary in some combinations, or opposing in others.
Considering calcium and potassium in combination, the latter gains ascendency in relative activities as the ratios between the calcium and the potassium become narrower.
Thus, as calcium is more nearly weathered out of the soil, potassium becomes relatively more active in moving into the plant.
Here is the physico-chemical soil situation that provokes the protein-carbohydrate relation—which in turn represents the “grow” foods versus “go” food situation, so prominently basic in our hidden hungers.