8 MASS. EXPERIMENT STATION BULLETIN 388 



The Absorption by Food Plants of Chemical Elements Important in Human 

 Nutrition. (Walter S. Eisenmenger and Karol J. Kucinski.) Some plants have 

 the ability to take up certain chemical elements from the soil in amounts greater 

 than normal, depending both on the ion involved and on the species of plant. 



In previous trials, an increase in the amount of magnesium, sodium, potassium, 

 and chlorine added to the soil resulted in increased intake by the plant. In the 

 present experiments, sodium, potassium, and magnesium were compared with 

 calcium; and phosphate and sulfate were compared with chlorine, bromine, and 

 iodine, in this respect. 



The increased intake of potassium, sodium, or magnesium, due to the addition 

 of these ions to the soil, was more pronounced than the increase in calcium re- 

 sulting from the addition of similar chemical quantities of calcium. Also, the 

 percentage increase of chlorine, bromine, and iodine in the plants when these 

 elements were added to the soil was higher than that of sulfur or phosphorus 

 when similar chemical quantities of these anions were added. 



This indicates that those elements which are more abundant in sea water than 

 in soil water are the ones which can be introduced into plant tissue with little 

 difficulty. In some respects it would seem that our land plants have not fully 

 adjusted themse'ves to a land environment. 



The Intake by Plants of Elements Applied to the Soil in Pairs Compared to 

 the Intake of the Same Elements Applied Singly. (Walter S. Eisenrnenger and 

 Karol J. Kucinski.) Cabbage, lettuce, beans, and celery were grown on plots 

 to which various elements had been added, in pairs, in quantities known to be 

 excessive but not toxic. Chemicals compounds, used in all possible combina- 

 tions of two, supplied calcium, potassium, and sodium at the rate of 250 parts per 

 million of soil and lithium at the rate of 100 parts per million. The exceeding 

 toxicity of lithium to plants necessitated application at the lower rate and at a 

 considerable time before planting. The calcium intake by cabbage, celery, and 

 lettuce was decreased when either sodium or potassium salts were applied with the 

 calcium. The potassium intake was increased in this combination. The lithium 

 intake was decreased when potassium was applied with the lithium. The potas- 

 sium intake was decreased somewhat when plants were grown on a combination 

 of potassium and sodium. 



Magnesium Requirements of Plants. (Walter S. Eisenmenger and Karol J. 

 Kucinski.) Various species of plants have been grown on a plot known to be 

 deficient in magnesium. There is little evidence to indicate a reason for the varied 

 reactions of different plants to the scarcity of magnesium ions in the soil. Dif- 

 ferent members of the same family react differently. Sudan grass shows no 

 symptoms, nor does timothy; but regular field corn becomes chlorotic, and hybrid 

 sweet corn scarcely sets any seed. Pumpkin vines show distinct chlorosis; water- 

 melons do so only at maturity. 



There is evidence now that plants ma\- suffer from the lack cf this element, yet 

 may not show any chlorosis or lack of chlorophyll formation. Strawberry plants 

 do not become chlorotic, yet new runners are formed more abundantly and the 

 strawberry row is wider where magnesium is applied, while the row becomes 

 narrow where no magnesium is applied. The very common garden weed, purslane 

 (Portulaca oleracea), called by the farmer "pussley," forms a thick mat where 

 magnesium was applied and ceases to grow, except in rare instances, where the 

 soil is deficient in magnesium. If a plant can be found, it is not chlorotic. Apple 

 leaves from trees on magnesium-deficient soils are not chlorotic, but areas of the 

 leaves become dark brown and eventualK' die, much like the leaves from a potash- 

 deficient plant. 



