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New York AGRICULTURAL EXPERIMENT STATION. 247 
FERTILIZER EXPERIMENTS WITH POTATOES. 
Wuicu ELEMENT IS DoMINANT FOR POTATOES ? 
In 1888 a series of experiments were attempted with a view to 
gaining some further information on the question, which fertiliz- 
ing element is dominant for potatoes. It is well-known that potato 
tubers contain a large amount of potash (59.8* per cent of the 
ash), hence the practice which largely prevails of supplying a 
potash dressing for this crop, but it has been believed by some 
that in the presence of available nitrogen, potatoes were able te 
gather the requisite potash even from soil poor in that element, 
or in which it exists in a state of great dilution. 
This trial was planned.to supply to five plats a sufficient 
amount fof phosphoric acid and nitrogen for. a full crop, and, — 
perhaps, more than the crop could use to advantage, in order that 
there could be no check in growth due to a lack of either of these 
elements, where different amounts, different forms, or no potash 
at all, was under trial. To each of five adjacent plats, phosphoric 
acid and potash were applied in amounts sufficient for the needs 
of a full crop, and nitrogen in different amounts and forms was 
applied to four, while one was left with no application of nitrogen. 
The plats to which these applications were made, were used for 
row comparisons of different amounts of seed, and by an over- 
sight the comparisons were not arranged so an equal amount of 
seed was planted on each plat. This so disturbed the results that 
nothing -could be done with the data that season, for the yields 
were in harmony with the amounts of seed planted per plat, and, 
although there were differences, one could not say they were due 
to fertilizer. 
_ This season, part of the plats having been used for other pur- 
poses, but this experiment has been continued on the remaining 
fifteen, and the same amounts of fertilizing elements reapplied to 
the same plats as received them last year, hence, whatever there 
may be of cumulative value from that fertilizing, will be present to 
help this year’s results. 



* How Crops Grow (Eng. ed.), p, 374. 
