GRIMSLEY. | Gypsum as a Fertilizer. 133 
By this means the potash in solution reaches the roots of the 
plants. This method of supply is of especial advantage to the 
deep-rooted plants, as in the order Leguminossze—the clovers, 
beans, etc., which contain a considerable percentage of potash 
in their tissues. 
Soils with abundant potash would not need gypsum, and soils 
with no potash compounds would not be benefited in this re- 
spect by gypsum. | 
This is the most modern view of the chemical value of gyp- 
sum as a fertilizer, and one which is held by most of the modern 
agricultural chemists. Boussingault’s experiments and analyses 
referred to a few pages back, showed an increase in the amount 
of potash on land which had been covered with gypsum. ‘This 
increase is explained by this chemical theory of action of plaster 
setting potash free from insoluble potash silicates. Potash fer- 
tilizers are displacing gypsum somewhat, but plaster still re- 
mains a valuable and cheap fertilizer. 
In our own state this feature of gypsum manufacture has not 
attracted much attention because of the natural fertility of the 
soils. Very little if any fertilizer is yet required by Kansas 
farmers. If the old theory of the moisture-absorption proper- 
ties of gypsum was true, gypsum would be in great demand in 
many parts of Kansas, but gypsum cannot do the work of irri- 
gation. 
