MINERAL COMPOSITION OIF CROPS 47 



Naftel (426), investigating Alabama soils in 1937, found that liming 

 with increasing increments of CaC0 3 increased the percentage of 

 calcium in the plants but decreased the magnesium, potassium, 

 phosphorus, manganese, and iron. Where soils were limed with 

 dolomite there were similar decreases in mineral content, with the 

 exception of magnesium, which was increased. 



THE MINOR FERTILIZER ELEMENTS 



Carolus (109) found that the addition of magnesium to the soil had 

 a more pronounced effect on the magnesium content of the plant than 

 it did on the yield or the nitrogen or calcium contents. Scharrer and 

 Schropp (508) observed, in 1938, that the efficiency of magnesium 

 absorption is clearly correlated with the natural magnesium content 

 of the soil, decreasing with an increase in soil magnesium. An increase 

 in magnesium fertilization, they state, resulted many times in an 

 increase in the magnesium content of the plant, but the highest 

 efficiency in absorption was found when the least magnesium was 

 applied. Garner, McMurtrey, Bowling, and Moss (201) showed that 

 the use of 120 pounds of magnesium applied to the Collington sandy 

 loam in Maryland increased the magnesium content of tobacco leaves 

 and prevented symptoms of magnesium hunger. 



The application of magnesium resulted in increased content of this 

 element in corn stover, oats (grain and straw), barley (grain and 

 straw), millet, and buckwheat, but no increase was found in rutabagas 

 (roots or tops) or Sudan grass, according to the experiments of 

 Beaumont and Snell in Massachusetts (50). 



Wiaddrowska (591), in her experiments with magnesium, using 

 Polish soils, reported no increase in the magnesium content of lettuce, 

 cabbage, carrots, or beans, although the calcium content of all vege- 

 tables except cabbage was depressed as a result of magnesium 

 fertilization. 



Wheeler, Hartwell, Kellogg, and Steel (590) reported in 1906 that 

 sodium salts applied to Rhode Island soils increased the percentage of 

 phosphorus in the plant. The carbonate was more efficient in this 

 respect than was the chloride. 



Deficiencies of sulfur have been studied extensively in the western 

 part of the United States, and some of these investigations have 

 included determinations of the effect of sulfur on the chemical compo- 

 sition of the plant. 



In 1923, Neidig, McDole, and Magnuson (430) determined from 

 pot tests that the sulfur content of alfalfa grown in several Idaho soils 

 could be doubled by the application of sulfur at the rate of 100 pounds 

 per acre. Even greater increases were obtained when 500 pounds of 

 sulfur was applied. Smaller increases in sulfur were obtained when 

 gypsum or lime and sulfur were added to the soil. All forms of 

 sulfur produced an increase in the total nitrogen removed by the 

 alfalfa. They stated, furthermore, that "the arid soils gave a greater 

 [yield] response to applications of phosphorus and less to sulfur than 

 did the humid soils." All applications of phosphorus increased the 

 percentage of sulfur in the alfalfa and produced in all but two of these 

 soils slight increases in the nitrogen content of the alfalfa. 



