INVESTIGATIONS AT ARDMORE, S. DAK. 27 



tons per acre, and only once was the yield less than 1 ton. In feeding 

 tests with steers conducted at the station, sorgo closely approached 

 alfalfa in feeding value. The dependable production of nearly 2 

 tons of feed per acre is of great value in a livestock-production 

 program. 



No total failure of the corn crop occurred during the period of 

 the experiments, but there were several years when little or no ear 

 corn was produced. The silage production of corn was only about 

 half as high as that of sorgo, and the difference in favor of sorgo 

 was greater in poor than in good years. Sorgo is the more produc- 

 tive feed crop, but corn is more valuable in years when a good crop 

 of ear corn is produced. The greater ease of handling a corn crop 

 and the need for ear corn for feed make corn the preferred cultivated 

 crop. It is believed, however, that part of the corn acreage could 

 be advantageously planted to sorgo. 



In the field rotation just described, the sorgo was grown on fal- 

 lowed land and the corn or sorgo land. Since its yields are in- 

 creased by the use of fallow, sorgo had the preferred place in the 

 rotation. In 1924 a new field rotation was started in which the corn 

 followed manured fallow and the sorgo was grown on corn ground. 

 In this rotation the sorgo was planted with a lister from 1927 to 

 1932. The yield of corn was proportionately greater than on the 

 rotation previously described, and the yield of sorgo was smaller. 

 The production of sorgo, however, remained higher than that of 

 corn, in spite of the fact that sorgo does not do its best in this 

 locality when planted with a lister. 



Both of these rotations show that a fairly dependable production 

 of feed may be obtained from corn and sorgo, and that good grain 

 yields can be produced in most years. Neither of the rotations is the 

 best that could be selected for general farm use. One cannot afford 

 to grow corn after sorgo or sorgo after corn. Yields of small-grain 

 crops are higher after a cultivated crop than after small grain. On 

 the other hand corn and sorgo yield no more after cultivated crops 

 than they do following small grain. Results obtained from rotations 

 indicate that both corn and sorgo should be followed by small grain, 

 the kind to be grown depending on the disposal to be made of 

 the crop. 



The need for barley for feed led to the establishment of a field of 

 alternate barley and manured fallow in 1926. In this rotation the 

 fields were 10 acres in size. The yield was below 25 bushels per 

 acre in only 1 of the 6 years, 1927-32, and averaged 37.7 bushels. 

 During the same years the average yield of barley from all plots 

 was 24 bushels per acre. The average yield of all plots was below 25 

 bushels in 3 of the 6 years. Yields indicate that the same surety of 

 production may be expected from fields as from plots. They also 

 show that in years of exceedingly severe drought, such as 1931, even 

 grain on fallowed land may fail to produce a crop worth harvesting. 



VARIETAL TESTS 



Varietal tests with grasses and forage crops were started in 1914. 

 Forage-crop tests were carried on consistently, except for 3 years 



