40 IOWA ACADEMY OF SCIENCE Vol. XXVI, 1919 



of the plant, destroying the vegetation, defacing buildings and 

 improvements, and defiHng the atmosphere. This same dust car- 

 ries most of the potash found in the shale, and should be saved. 



Mr. George P. Dieckmann, Chemist of the Northwestern States 

 Portland Cement Co., advises me that the dust loss in the modern 

 Portland cement plant is calculated at five per cent of the raw 

 mix. This means a loss of about fifteen tons in the manufacture 

 of 1000 barrels of cement. The total daily capacity of the four 

 Portland Cement Plants in Iowa is about 20,000 barrels, with a 

 dust loss of about 300 tons per day. The amount of potash car- 

 ried is about 4 per cent, of which more than one half is water-sol- 

 uble. Mr. Dieckmann has done enough experimental work to 

 demonstrate that some 90 to 95 per cent of the potash may be re- 

 covered electrolitically. Nothing has been done as yet to save 

 this important resource in the Iowa plants. 



While the value of the normal mineral output amounts to a few 

 tens of millions of dollars, the value of the products of the soil 

 finds expression in hundreds of millions and is after all the real 

 basis of the wealth of the state. The conservation of the soil and 

 its fertility is our greatest material problem to-day. Soil losses 

 are chiefly mechanical and chemical, and while all soils are under- 

 going constant changes through natural agencies, the losses are 

 greatly stimulated through unwuse or careless agricultural proc- 

 esses. 



The removal of the natural vegetation subjects the land to un- 

 due wash by rain and running water and careless methods of 

 farming, or cultivation of the land during the wrong season of 

 the year may greatly aid such soil wastage., Oftentimes the eros- 

 ive work of running water is sufficient to more or less completely 

 remove the soil through gullying and sheet erosion, rendering the 

 land untillable for the time being or indefinitely. Up to the pres- 

 ent time not much of our Iowa land has been lost in this way. 

 Most Iowa farmers are sufficiently alert to note the "hand writ- 

 ing," and have adopted or are adopting methods to reduce soil 

 erosion to a minimum. 



The chemical waste of soils or loss in soil fertility is less obvi- 

 ous and the tillers of the soil are much slower to recognize such 

 losses and to appreciate the fact that corrective measures must be 

 discovered and put into eflfect. Our agricultural Experiment Sta- 

 tions are pioneers in the work of soil conservation and are doing 

 excellent service in bringing the matter of soil waste to the at- 



