AbstractsEarth & Environmental Science

The relation of lime and magnesium to each other in plant growth is a problem over which the Agronomist and Plant Physiologist have stumbled for some time, and before its solution is finally reached, will likely involve the consideration of several other mineral elements which are not now generally believed to function with them. It has been known ever since the time of Aristotle that lime is beneficial to most soils, and since then it has been used in all its forms as a condiment; sometimes with success; sometimes with medium results and sometimes with apparent failure. SIR JOHN BENNET LAWS and SIR JOSEPH HENRY GILBERT were the first to make accurate observations upon the practice of liming. They found that the white or "fat lime" would produce better yields than the gray or "poor lime" which was sometimes injurious. From observations of this kind there has grown up the practice of applying lime to soils stiff and poor in texture. Magnesium on the other hand is never applied since it has no such beneficial action, and is supposed to exist in sufficient quantities for all necessary needs of plant growth. This in general is true, as most soils in America and Foreign Countries, contain more lime than magnesium. However, there are instances where the magnesium content of some soils is below that of lime, and applications of magnesium to these soils would be found beneficial. It will be the purpose of the following pages of this paper to discuss the Physical, Chemical, Bacteriological and Physiological relations of Calcium and Magnesium to soils and their effects upon plant growth. And while some of these theories are somewhat obsolete, the majority are new and apparently true.