122 HATCH EXPERIMENT STATION. [Jan. 



Farmers raising the crop on such soils should demand potato 

 fertilizers in which this salt has been used as the source of 

 potash. Not only is the crop almost invariably larger on 

 the sulfate, but it is of superior eating quality. Previous 

 experiments here have shown that it almost invariably con- 

 tains from 2 to 3 per cent, more starch, and that when cooked 

 the potatoes are whiter, of better flavor, and more mealy. 



III. — Fertilizers for Garden Crops. (Field C.) 

 The object in this experiment is to study the influence of 

 a few standard fertilizers used continuously upon the same 

 land upon the yield of garden crops . The experiments were 

 beo-un in 1891, and from that date to 1897 inclusive fertili- 

 zers alone were applied to the land. During the past six 

 years stable manure also has been applied in equal quanti- 

 ties (at the rate of 30 tons per acre) to each of the plots, 

 while the fertilizers have been used in the same amounts and 

 applied to the same plots as at first. The original number 

 of plots in the experiment was six, of about one-eighth of an 

 acre each. On all of these fertilizers were used. When we 

 first began to apply manure as well as fertilizers, we intro- 

 duced into the experiment a seventh plot of the same area 

 as the others, but which had had difi'erent previous manurial 

 treatment. To this we have since applied manure only at 

 the above-named rate. This plot was introduced in order 

 that we might have a basis for determining whether the 

 materials used were in any degree beneficial when added to 

 the somewhat liberal quantity of manure employed. It was 

 found that at first the yields of almost all crops on the ma- 

 nure alone were ahnost as good as those where the fertilizers 

 also were used. In a few cases the manure alone gave the 

 better crops. It is not believed that we are justified in con- 

 cluding that the fertilizers have been used without beneficial 

 efiect, for the no-fertilizer plot introduced in 1898 had, pre- 

 vious to that year, been more heavily manured than the other 

 plots. The superiority of the plot receiving manure alone 

 seems to be gradually decreasing, and this plot will doubt- 

 less ultimately serve as a basis for making fair com})arisons 

 between the results obtainable Avith manure alone and results 



