Oct. 4, 1915 
Effect of Alkali Salts in Soils on Crops 
11 
From Table VII it will be seen that germination was first retarded by 
the salts when the soils contained but a small amount of moisture. 
With most of the salts the highest germination was in the wettest sand, 
while with sodium chlorid the intermediate moisture gave the highest 
germination. 
It will be noted that in the sand sodium carbonate was more toxic 
than sodium chlorid. This same relation is also reported later in this 
paper with sand, although in all the tests with loam sodium chlorid was 
more toxic than sodium carbonate. A comparison of the limits of 
growth in sand with those already reported for loam brings out the fact 
that germination is reduced by a much lower concentration in sand than 
in loam. This is also brought out clearly in results reported later. 
OUTLINE OF LATER WORK 
GENERAL METHODS OF EXPERIMENTATION 
A number of experiments were conducted in glass tumblers in which an 
equivalent of 200 gm. of dry soil was placed. Salts were added to the 
soil as follows: A stock solution of each salt was made up, containing 
an equivalent of 10 per cent of the anhydrous salt. The necessary 
quantity of the stock solution was then added to sufficient distilled water 
to make the soil up to 20 per cent water on the dry basis. The water 
containing the solution was thoroughly mixed with the soil on oilcloth 
and the whole placed in the glass. This method insured an even dis¬ 
tribution of the salt through the soil. 
In all cases the soil was made up to 20 per cent with moisture. This 
was about the optimum amount for plant growth. Ten seeds were 
planted in each glass to a depth of l /i inch from the surface. After the seeds 
were planted the glass tumblers were covered with panes of window 
glass until the plants were up. This prevented evaporation and enabled 
the seeds to germinate with an even soil-moisture content. 
Counts were made of the number of plants up each day, which made 
possible a determination of the relative time required for germination in 
the different treatments. The original moisture content was maintained 
by adding the necessary quantity of water every day or two. The plants 
were allowed to grow for two or three weeks, when they were harvested 
and measured and the dry weights determined. 
The data obtained for each glass therefore included (1) the percentage 
of germination, (2) the average time required for germination, (3) the 
average height of plants, (4) the average number of leaves, and (5) the 
dry matter produced. 
In each test there were 15 glasses for each concentration of salts, and 
there were 10 concentrations. In addition, there were four check 
glasses to which no salt was added. This made 154 glasses for each test. 
In the series there were 24 tests, which gave a total of 3,696 glasses. 
