FIELD CROPS. 225 



grass, red clover, alsike clover, and white clover. It is noted that all of the 

 grasses made good growth during the summer except wheat grass, redtop, tim- 

 othy, blue grass, and orchard grass. 



Fall irrigation experiments with wheat, barley, oats, corn, potatoes, and sugar 

 beets showed an average increase in yield of all the crops in favor of fall (Sep- 

 tember) irrigation amounting to 16 per cent. The increase with potatoes, how- 

 ever, seems to be insignificant, only 2 per cent, while with the other crops the 

 increase was from 15 to 23 per cent. 



Sugar beets cultivated to a depth of 3 in. throughout the season yielded an 

 average of 16.3 tons for two years; a first cultivation to 3 in., subsequent culti- 

 vations shallow, and knife attachments on the cultivator, 18.3 tons; and shallow 

 cultivation throughout the season 39.1 tons per acre. 



Experiments in plowing 4, 8, 12, 16, and 20 in. deep for sugar beets showed 

 that "while the results were not consistent, the highest yield was obtained 

 from shallow plowing. The effect of varying the depth of plowing probably 

 would differ on different soils. The soil at the experiment farm is a light sandy 

 loam and probably does not require as deep plowing as heavier soils." 



In an experiment regarding distance of planting sugar beets " rows were 

 planted 20, 24, and 28 in. apart, and in each of these plantings the beets were 

 thinned to 6, 9, 12, 15, and 18 in. in the row. The results so far obtained in 

 this test have been very inconsistent, but in general the closer spaced plats have 

 produced the highest yields." 



In regard to potatoes " 11 standard varieties of potatoes were tested in 1913, 

 together with 21 seedling stocks. These were tested in single plats on land 

 which grew alfalfa in 1912. The highest yield with the named varieties was 

 produced by the Pearl, which yielded 314.9 bu. per acre. The Eureka was sec- 

 ond, with a yield of 247.9 bu. per acre. One of the seedlings, not yet named, 

 gave the highest, total yield in 1913. It produced 370 bu. per acre." It is noted 

 that with potatoes as with sugar beets summer rains interfered with irrigation 

 plans and no consistent results were secured. 



The tillage work consisted in deep and shallow ditching preparatory to irri- 

 gation. " The average yield in 1912 and 1913 for shallow ditching was 197.4 

 bu. per acre, as compared with 173.9 bu. per acre for deep ditching." 



The work of the Yuma reclamation project experiment farm in 1913, 

 R. E. Blair (U. S. Dept. Agr., Bur. Plant Indus., Work Yuma Expt. Farm, 

 1913, pp. 1-11, figs. Jf.). — ^This briefly outlines the work of the experiment farm 

 located near Yuma, Ariz., as carried on jointly by several otfices of the Bureau 

 of Plant Industry, and continues previous studies (E. S. R., 229, p. 330). Cli- 

 matic and crop conditions of the project are briefly discussed. 



In experimenting for a suitable green manure alfalfa was found to be the 

 most satisfactory crop, although for a quick summer crop to turn under cow- 

 peas seem to have given good results. In the production of alfalfa it is noted 

 that in cases where the crop began to fail after three or four years, the subsoil 

 proved to be unfavorable and prevented the taproot development and induced 

 surface root system which did not prove suflicient for the needs of the crop. 

 By plowing under the crop every two or three j-ears and introducing a culti- 

 vated crop for a season, it is suggested that the soil would again be in condition 

 to produce a maximum yield of alfalfa, for alfalfa seed is the chief money crop 

 of this project. Cotton is suggested as being most suitable for this rotation. 



In regard to the production of cotton on the alkali soils it is noted that " sev- 

 eral significant observations were made upon the production of cotton from 

 soil containing high percentages of alkali salts, chiefly sulphates and chlorids. 

 Cotton was grown well on certain fields where other crops had previously been 

 killed by the presence of excessive amounts of these salts. In one case where 



