34 BOTANICAL GAZETTE [SEPTEMBER 
OLSON (19), sulphur fertilization of alfalfa caused increased yields 
of 200-300 per cent. 
The purpose of the present investigation was (1) to increase our 
knowledge of the sulphur content of soils, and (2) to study the 
relation of sulphur to chlorophyll development in certain plants 
and its effect on the yield of these plants. The phosphorus content 
of all the soils was also determined. Phosphorus, together with 
nitrogen, is considered the most generally limiting element of crop 
production in the soils of the United States. It was thought that 
it would be interesting to compare the sulphur content of the soils 
with their content of such an element as phosphorus. | 
Investigation 
SOIL ANALYSIS 
It is important for American agriculture to discover how many 
soils in the United States are suffering from lack of sulphur, as are 
the Oregon soils to which reference has already been made.. The 
Oregon results might be duplicated, perhaps, in the case of many 
other soils; on the other hand, many soils are probably not lacking 
in sulphur. The samples were chosen with a view of giving some 
idea of what range in sulphur content might be expected in the 
soils of the eastern and central United States. Thus, samples 
from the Atlantic and Gulf coast regions, from one of the southern 
states, from certain of the north central states, and from Chicago 
were analyzed. Investigations on the Atlantic coast during the 
early history of the United States showed great benefits from the 
use of gypsum as a fertilizer. It was thought that the analysis of 
certain of the coast soils might give some interesting results. On 
the other hand, soil analyses and sulphur fertilization tests in 
the central states may be said to indicate, in general, a higher sul- 
phur content in the soils of this section than in the coast soils. 
It was desired to analyze a number of soils of the central states to 
compare with the coast soils. It is well known that rain carries 
down much more sulphur from a smoky atmosphere than from 
one less contaminated with smoke. It was thought that the 
Chicago soils might prove to have a very high sulphur content, 
owing to this fact. 
