. Principles of agricultural chemistry [microform] . sh but no phosphoric acid,the grain hardly ripens at all. The use of phosphoric acid, how-ever, hastens the maturity of the plant. Fertilizer Experiments.—A great number of fertilizer experi-ments have been carried out by Experiment Stations, and otherinvestigating agencies. The plans of the experiments vary a greatdeal, according to the crop to be tested, the information desired, 326 PRINCIPLES OF AGRICULTURAL CHEMISTRY etc. The fertilizer is applied to plots varying from 1/50 to 1/2an acre, but generally of i/io to 1/20 acre. The effect of
. Principles of agricultural chemistry [microform] . sh but no phosphoric acid,the grain hardly ripens at all. The use of phosphoric acid, how-ever, hastens the maturity of the plant. Fertilizer Experiments.—A great number of fertilizer experi-ments have been carried out by Experiment Stations, and otherinvestigating agencies. The plans of the experiments vary a greatdeal, according to the crop to be tested, the information desired, 326 PRINCIPLES OF AGRICULTURAL CHEMISTRY etc. The fertilizer is applied to plots varying from 1/50 to 1/2an acre, but generally of i/io to 1/20 acre. The effect of thedifferent applications is measured by the weight of the producton the different plots. The only variable should, of course, bethe fertilizer. All other conditions should be the same for allthe plots. The crop, however, is subject to other variables, suchas differences in soil or subsoil, in stand, damage by insect pests,nearby trees or fences, etc. The best results are secured whenthe experiment is carried out on the same land for a number of. A B . Fig- 75- — Tobacco, fertilized (A), and unfertilized (B). Ohio Station. years to eliminate seasonal differences. It is also well for plotsto be repeated a number of times in order to eliminate error dueto inequalities of the soil. In order to study the effect of variable soil on the crop, severalexperiments have been made in which a field of apparently uni-form soil, bearing a crop under similar conditions in all parts, hasbeen subdivided and harvested in separate small areas. Com- PURCHASE AND USE OF FERTILIZERS 327 parison shows the differences between these, and combination andcomparison shows the differences of larger areas. For example,Morgan^ selected a strip of land 112^ feet wide apparently uni-form in texture, etc., which was planted in wheat first and thencorn. It was measured off in strips 15x112^ feet, (about 1/25acre) and the wheat or corn harvested separately from 63 plotswhich should thus be all alike. With th
Size: 1890px × 1322px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidprinciplesof, bookyear1913
