
FIELD EXPERIMENTS WITH FERTILIZERS. Ey 
SOIL TEST EXPERIMENTS. 
In 1890 the Station began at Storrs, on the same field as 
that used for the special nitrogen experiments, a series of 
experiments known as “‘ soil tests.’? The purpose was to study 
the deficiencies of soils and the particular needs of different 
crops for the different ingredients of fertilizers. "The fertilizers 
used in these soil tests are, in general, of the same kinds of 
materials—dissolved bone-black, muriate of potash, and nitrate 
of soda—as those used in the special nitrogen experiments, and 
supply the phosphorus, potash, and nitrogen in the same com- 
binations. In the special nitrogen experiments a uniform 
mixture of the mineral fertilizers—super-phosphate and potash 
salt—is used as a basis, and to this nitrogen is added in 
increasing proportions. In the soil test experiments the phos- 
phoric acid, potash, and nitrogen are applied upon parallel 
plots of land first singly, then two by two, and finally all three 
together, as shown in the diagram on page 1098. 
For this series of soil test experiments a double group of 
plots was arranged as explained in the following paragraph, 
and upon these the experiments have been continued year by 
year, with the same plots and the same kinds and amounts of 
fertilizers on each indicated in the diagram below. ‘The crops 
used in these experiments were grown in the following rota- 
tion, beginning with 1890: corn, potatoes, oats, cow peas, 
corn, potatoes, oats, soy beans, corn, potatoes. The experi- 
ments of 1897, 1898, and 1899, here reported, are the eighth, 
ninth, and tenth of this series, the crops grown in those years 
being respectively soy beans, corn, potatoes. The results of 
experiments previous to these are given in the annual Reports 
of the Station up to and including 1896. 
The method of dividing the field into plots for these experi- 
ments, and the kinds of fertilizers and the amounts per acre 
used on each plot, are illustrated by the following diagram. 
The plots are laid out with the long dimension north and 
south. The field slopes gently to the south, but with not 
enough incline to cause serious washing and cutting of the 
surface by water. The soil of the field is a heavy loam, with 
a yellow clay loam subsoil. In 1888 and 1889, when the field 
was being cropped preparatory to being laid out for this series 
of experiments, it was noticed that the soil seemed to be poorer 
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