126 EXPERIMENT STATION EECOED. 



• 



loam soils. This result is ascribed to the strong absorptive power of such soils 

 for potash. 



A decided increase in yield of fodder beets followed applications of sodium 

 chlorid and sodium sulphate, especially the former. No such result was obtained 

 in the case of magnesium salts, and magnesium chlorid was positively harmful. 

 Magnesium chlorid, and in certain cases sodium chlorid, increased the assimila- 

 tion of soil potash without increasing the yield. 



Large applications of magnesium sulphate (0.25 to 0.5 per cent) produced 

 beneficial results, especially on calcareous loam soils, and even with applica- 

 tions of 1 per cent there was an appreciable increase in yield of grain on such 

 soils. Similar results were obtained with sodium sulphate. On sandy soils, 

 however, the sulphates were injurious in all cases, but not to the same extent 

 as the chlorlds. Magnesium and sodium chlorids applied at the rate of 0.25 per 

 cent were not injurious on calcareous loam soils, but were injurious when 

 applied in double this amount. On loam soils poor in lime applications of 0.25 

 per cent reduced the yield of grain and on sandy soils these salts in all 

 amounts applied absolutely prevented the growth of plants. The chlorids in- 

 creased the assimilation of lime while the sulphates reduced it. 



It is pointed out that these results obtained in pot experiments are obviously 

 not applicable in practice except in so far as they indicate that sulphates may 

 be safely used in larger amounts than the chlorids. Phonolite showed very 

 little effect as compared with potassium chlorid and carbonate applied to pota- 

 toes, wheat, and a mixture of oats aoad clover. 



The field experiments indicated that potash salts were not needed for potatoes 

 which had received a liberal application of manure. On sandy soils spring 

 application of potash salts gave better results than fall application. The per- 

 centage of starch was lower, but the total yield was larger. On loam soils the 

 reduction in starch was greater than that in sandy soils. There was little dif- 

 ference as regards the efi'ect of spring and fall application, except that in gen- 

 eral the starch was reduced to a greater extent by spring application. The yield 

 was slightly less with 40 per cent potash salt, and the starch content slightly 

 greater, than with kainit. Normal applications of phonolite were almost with- 

 out effect; larger applications had little effect upon yield but showed less re- 

 duction of starch content than the potash salts. Potassium carbonate increased 

 the starch content of potatoes. 



The potash fertilizers increased the yield of dry matter and sugar in sugar 

 beets on all soils, the best results being obtained with fall application. On loam 

 soil 40 per cent potash salt and kainit were about equally effective. The 40 

 per cent salt was slightly better on heavy soils. Phonolite was almost without 

 effect on sugar beets. 



Potash salts increased the yield of fodder beets both with and without 

 manure except on humus soils (with manure). Slightly larger yields were ob- 

 tained with fall application. The 40 per cent salt gave a slightly larger yield 

 of dry matter than kainit. Like the potato, but unlike the sugar beet, the 

 fodder beet appears to be especially sensitive to large applications of potash 

 salts. Phonolite had little effect. 



Fall application of potash salts gave better results than spring application on 

 wheat. Kainit and 40 per cent salt were about equally effective on humus loam 

 soil. On heavy loam soil the 40 per cent salt gave better results. Phonolite 

 was ineffective. 



No benefit was obtained from the use of potash salts on rye. The results 

 were very variable with barley, and were inconclusive as regards spring and 

 fall application. The 40 per cent salt appeared to be somewhat more effective 

 than the kainit for this crop. 



