Idl7] FIELD CROPS. 833 



Limiting factor studies witli various fertilizers are reported in tabular form. 

 Beport on the manuring of mangels, J. Porter and A. S. McWilmam 

 {Herefordshire Ed. Committee, Farmers' Bui. 9 (1915), pp. 9). — Tliis is a report 

 of fertilizer experiments witli mangels which have been in progress since 1908. 

 Five combinations of commercial fertilizers were used in the test in addition 

 to a dressing of barnyard manure of from 12 to 14 tons per acre. All of these 

 fertilizer applications were made at seeding time, and on four of the five 

 fertilized plats a top-dressing of sodium nitrate was added at singling time. 

 The fertilizers used were ammonium sulphate, nitrolime, nitrate of soda, cal- 

 cium nitrate, acid phosphate, basic slag, potassium sulphate, and sodium 

 chlorid. All the treatments were made in triplicate at each of the 11 centers 

 where the experiments were conducted. The general conclusions drawn from 

 the experiments to date are as follows: 



All mixtures of fertilizers when used with farmyard manure have been fol- 

 lowed by profitable returns, the average Increases varying from 4 to 7 tons 

 per acre. A top-dressing of sodium nitrate has resulted In an average increase 

 of mangels of 3 tons per acre, and when the nitrogen was applied in the form 

 of calcium nitrate the same average increase was obtained at approximately 

 one-half the cost. With ammonium sulphate slightly higher results have been 

 obtained than with its equivalent in nitrolime. Acid phosphate on gravelly 

 soil gave better results than basic slag, while on the heavier soils the results 

 were almost identical. The followins: mixture of commercial fertilizers has 

 given the largest increase in yield and the greatest profit : 0.5 cwt. ammonium 

 sulphate, 3 cwt. acid phosphate, 0.5 cwt. potassium sulphate, and 2 cwt. salt 

 applied at seeding time, with 1.25 cwt. calcium nitrate applied as top-dressing 

 shortly after singling. 



A classification of the varieties of cultivated oats, W. C. Etheridge (New 

 York Cornell Sta. Mem. 10 (1916), pp. 81-172, pis. 22, figs. 22).— This reports 

 the development of a usable system of classification of the American varieties 

 of oats grown in the environment of New York State in an effort to clear to some 

 extent the confusion in varietal nomenclature. A review and discussion of the 

 work of others has shown that a classification of oat varieties, in order to be 

 effective, must be based on the morphology of the plant. The present cassifica- 

 tion, therefore, follows (1) a study of the morphology of the plant to discover 

 the various characters by which individual varieties may differ; (2) an analysis 

 of varieties en masse to reach the types which for present purposes are con- 

 sidered elemental, that is, types that differ in one or more morphological char- 

 acteristics ; and (3) an arrangement of varieties in groups regardless of nomen- 

 clature, according to their likeness to the elemental types that represent the 

 groups. The groups are fully described and named, and a key constructed for 

 their identification. The naming of groups consisted in applying the name that 

 occurred most frequently among the specimens of each group, although all 

 additional different names were reserved and arranged as synonyms. 



Specimens numbering 731 have been classified in the study, the bulk of which 

 were brought together in 1909 at the Nebraska Experiment Station by E. G. 

 Montgomery and M. S. Jussell, who laid the foundation for this work. The 

 original collection included all varieties then grown or offered for sale in the 

 United States. During 1913, 1914, and 1915 this collection was supplemented by 

 accessions from the Office of Cereal Investigations of the U. S. Department of 

 Agriculture (with which the author cooperated) and from various other sources. 



The morphology of the oat plant is discussed in considerable detail, together 

 with a description of the important taxonomic characters, and their uses in 

 previous classifications and in the present one explained. 



