1911.] PUBLIC DOCUMENT— No. 31. 15 



abmulaiit. They appear to be somewhat less al)nn(Uiiit on tlie 

 muriate of potash than on the sulfates, and there seems to be 

 a ditference in the relative proportions of white and red clovers 

 on the two snlfates, the former being relatively most abundant 

 on the low-grade sulfate, while the red clover has been most 

 luxuriant on the high-grade sulfate of potash. It should he 

 remembered, in estimating the significance of this observation, 

 that no seeds of any kind have been sown in these fields; and 

 it is further important to keep in mind the fact that the soil 

 conditions, as has been indicated, vary quite widely in different 

 portions of the area under consideration. It may be, there- 

 fore, that the diiferences in proportion of white and red clovers 

 just referred to are due either to accidental conditions or to 

 variations in soil^ and not to the ditference between these two 

 salts. 



(4) The use of slag and either of the potash salts produces 

 on the average an increase in the crop considerably more than 

 sufficient to pay the cost of top-dressing with these materials. 

 The results demonstrate the ability of soils naturally adapted 

 to grass to produce profitable hay crops without frequent re- 

 plowing. 



(5) Close observation of the crops produced and of the gen- 

 eral conditions prevailing leads to the conclusion that these 

 fields are improving from year to year. The proportion of 

 weeds is decreasing, while that of clovers is increasing. 



(6) The use of nitrate of soda in connection with slag meal 

 and a potash salt usually gives a considerable increase in the 

 hay crop, in most cases more than sufficient to pay the cost; 

 but an application at the rate of 250 pounds per acre appears 

 to be in excess of requirements. If the season is characterized 

 by normal or alnmdant rainfall, the crops receiving nitrate of 

 soda at this rate almost invariably lodge badly, and, as a result 

 the yields are somewhat lessened. During years with abun- 

 dant rainfall, nitrate of soda at the rate of 150 pounds appears 

 to give as much increase in the crop as is produced by nitrate in 

 any larger amount, and while the yield on 200 pounds some- 

 times exceeds that produced by the lesser amount, it is the 

 writer's belief that the 150-pound rate for mowings similar to 



