858 
Journal of Agricultural Research 
Yol. XXVII, No. it 
in regard to those elements which have been determined by other investi¬ 
gators should be mentioned, however, for the purpose of comparison. The 
estimated amount of phosphorus, calcium, magnesium, potassium, silicon, 
and nitrogen removed per acre by the aerial parts of a Pride of Saline 
corn plant was respectively 22.17, 20.79, 19.40, 100.79, 96.37 and 155.77 
pounds. Schweitzer (10) considered 6,528 plants of corn per acre and 
estimated that 83 pounds of phosphorus, 8.9 pounds of calcium, 15 pounds 
of magnesium, 50 pounds of potassium, 43 pounds of silicon and 135 
pounds of nitrogen were removed from the soil by the stems, leaves, and 
ears of these plants. Hopkins ( 2 , p. 154) estimated that a com crop 
producing 100 bushels of grain and three tons of stover per acre would 
remove from the soil 148 pounds of nitrogen, 23 pounds of phosphorus, 
71 pounds of potassium, 17 pounds of magnesium, 22.3 pounds of calcium, 
5.2 pounds of iron and 6 pounds of sulphur. Jones and Huston (5) 
estimated that the aerial parts of Riley’s Favorite com removed, per acre, 
18.3 pounds of phosphorus, 76.2 pounds of potassium and 110.6 pounds 
of nitrogen. The estimated weight of these elements removed per acre 
by a crop of Pride of Saline com grown under the conditions of this ex¬ 
periment was considerably higher than that reported by Schweitzer. ( 10) 
and Jones and Huston (5). The greater yield of dry matter per acre as 
estimated from our experiment would account for a considerable portion 
of the differences, since in some cases, at least, the percentage composition 
is approximately the same as that reported by these investigators. Our 
estimations compare very closely with those of Hopkins (2, p. 75) with 
the exceptions of the amounts of potassium and sulphur removed by the 
crop. The relatively large amount of potassium in the plants grown at 
Manhattan, Kans., was due probably to the fact that the soil in which 
the plants were grown was especially rich in this element, while the small 
amount of sulphur obtained by the earlier investigators was due to the 
naccuracy of the methods used in its estimation. 
SUMMARY 
An elemental analysis was made of five Pride of Saline corn plants 
grown in the field at Manhattan, Kans., in 1920. Determinations were 
made for carbon, oxygen, hydrogen, nitrogen, phosphorus, potassium, 
calcium, magnesium, sulphur, iron, silicon, aluminum, chlorin and 
manganese. 
In order to determine the variation in the composition of the different 
plants and their organs, separate analyses were made of the leaves, stem 
and grain of each of the five plants. A separate analysis was also made 
of each of five root systems of plants that were grown in soil in large 
metal containers. 
The analytical results are tabulated and discussed in the text under 
the following headings: 
Variations in the percentage and in the total weight of the elements 
that composed the various organs of the plants. 
The percentage distribution of the different elements in the leaves,, 
stems, grain, cobs, and roots of the plants. 
The number of pounds of each of the elements removed per acre from 
the soil and air by a crop of com. 
