BULLETIN OF THE BUSSEY INSTITUTION. 81 
Purpose of the Experiments. —It was determined to test upon the 
soil of this*typical field the action of various fertilizers easily pro- 
curable in Boston. In order to allow for the varying influence of the 
seasons in different years, and for the sake of determining what would 
be the result of incessantly cropping such poor land, it was decided to 
continue the same set of experiments, without changing the kinds of 
crops or of manures, for as many successive years as experience might 
suggest. 
Arrangement of the Plois.—A portion of the field was divided into 
sections and plots, as will appear from the diagram on the next page. 
There were four distinct divisious of the experimental field, stretch- 
ing across it, as will be seen upon the diagram, looking from right to 
left. Each of these divisions was separated into two sections, 
marked A and AA, B and BB, ete. Each section was subdivided 
into three sets of plots, and each set of plots was, in its turn, divided 
into nine small squares. ‘lo each division some one general class of — 
manures was applied, but in somewhat different ways to the sections 
or halves of divisions. Each of the three sets of plots in every sec- 
tion carried a special kind of crop, and each of the final squares re- 
ceived either a particular variety of manure or a special quantity of 
manure, excepting always the middle square (No. 5) in each set of 
plots, which got no manure whatever. The manner in which the sets 
of plots and the final squares or units were arranged, marked, and 
numbered will appear from the diagram. Each of the final squares 
or units was 5 X 5 metres (1 rod = 5.0291 metres), i. e. very nearly 
riz of an English acre. The walks between the squares and plots 
were one third of a metre wide, that is to say, about one foot wide. 
Between the main divisions there were walks one metre wide.* 
* It may here be said that three years’ experience has fully justified the fitness 
of this arrangement for the field in question, both as regards the size of the squares 
and the width of the walks. Where a considerable number of manures are to be 
tested simultaneously, small plots are essential in order that the labor may all be 
performed by one or two trusty men ; that the processes of planting, cultivating, and 
harvesting may be made, in some sense, simultaneous, and consequently under equal 
or nearly equal conditions ; and finally, in order that proper storage-room may be 
found for the crops produced, where they may be brought to some one uniform con- 
dition of dryness before weighing, and may be weighed at one and the same time. 
Narrow walks between the plots and squares are desirable in order that no land 
shall be wasted, and that some approach to uniformity of soil among the different 
VOL. I. 1, 
