New York AGRICULTURAL EXPERIMENT STATION. 285 
to secure a cool, moist bed for the growing roots and leave room 
above the roots for the development in the warmer soil nearer the 
surface of a heavy yield of tubers. 
Attempts to increase the difference in conditions between soil of 
roots and soil for tubers by planting in ridges rather than on level 
ground or in furrows, or by mulching with straw between the 
ridged rows either gave results unfavorable to these practices be- 
cause of moist, cool seasons or were contradictory. With straw 
mulch the growth of weeds is a great detriment, so the final con- 
clusions appear to favor level culture, with maintenance of good 
soil mulch by shallow cultivation. The recorded tests®! of varying 
distances of planting are exceedingly contradictory. They some- 
times favor planting as thick as pieces twelve inches apart in rows 
twenty-two inches apart, while in other tests, to secure any satis- 
factory results from such thick planting, it was necessary to thin 
the shoots to one in a hill. The unthinned plants so shaded the 
ground that the total yield was greatly decreased and the percentage 
of small tubers greatly increased. In other tests rows forty-four 
inches apart with plants twelve inches apart in the row have given 
the best yields. 
From recent Station experience, not, however, based on definite 
distance comparisons, it would seem that for our heavy, productive 
soil and for varieties like Rural New Yorker No. 2 of which the 
tubers have a tendency toward excessive size, plants twelve inches 
apart in rows thirty inches apart would give best results in quantity 
and quality. 
Fertilizer tests— As already indicated, fertilizer tests on Station 
soil have generally been inconclusive. The use of fertilizers with 
potatoes has given increased yields, but these have usually not 
been profitable nor in proportion to the amounts applied. It was 
impossible to draw definite conclusions in regard to the separate 
fertilizer elements, but potash gave some decided gains on Station 
soil, especially in the form of muriate. In other and more extended 
tests on Long Island soils, the use of potash in any form or in 
any quantity did not give consistently profitable returns. For 
those soils, at least, the very liberal use of potash in the formulas 
generally applied on potatoes appears to be unwarranted. It is 
probable “that the physical relations of our soil have a greater 
influence on [the potato] crop than do the chemical relations.” In 
Rpts. 2:125 (1883) ; 3:73. 74 (1884) ; 4:63-65 (1885). 
