FIELD EXPERIMENTS WITH FERTILIZERS. 1 25 



of the results. Plans have already been made for experiments 

 on a more nearl}^ level piece of land, which is now being cropped 

 without manure in order to prepare the soil for the purpose. 



Each of the larger plots contains one-eighth acre of land, and 

 is sub-divided into six sections 1-50 acre each by paths crossing 

 the lots from east to west, as indicated in the diagram. The 

 sections on each plot are designated by the letters A-F shown 

 at the sides of plots o and bb in the diagram. It is generally 

 understood that the effects of fertilizers on the yields of crops 

 could probably be more accurately studied on the large plots 

 than on the smaller sections, because in the former case the 

 effects of irregularities of the soil upon the yield would be less 

 marked. In these experiments, however, the effects of nitrogen 

 of fertilizers upon the proportions of nitrogen compounds (pro- 

 tein) in the crop is believed to be the more important question, 

 and this can perhaps be studied as well upon the smaller sec- 

 tions as upon the larger plots. The advantage gained in sub- 

 dividing the plots into sections is in the opportunity to study 

 several different crops at the same time under like conditions, 

 thus giving the results from one set of experiments a wider 

 application . 



The name of the crop grown on each section is shown in the 

 diagram. Two series of sections, A and F, were planted with 

 the same variety of corn; two series, B and E, with soy beans, 

 and two series, C and D, with cow peas. In recording the 

 results with the cow peas and the soy beans the two series of 

 sections for each crop were treated as if there was but one 

 series; that is, the yields on corresponding sections of B and 

 E, and of C and D, were added together and samples were 

 taken from the combined crop. In the case of the corn, how- 

 ever, the results have been kept separate, because lime was 

 used on one of the two series of sections and not on the other, 

 as will be explained later. 



Expla7iation of tables. — Two tables of data are given in con- 

 nection with the discussion of the results for each crop. The 

 first table in each case gives the weight and cost of fertilizers 

 per acre, the weights of crop per section and the calculated 

 weights per acre, and the increase in yield from the sections 

 with fertilizers over the average of the yields from the sections 



