1917] FIELD CROPS. 733 



plants, especially during dry weather, is best with level culture, and that on 

 good soil well worked and under favorable moisture conditions the difierenoes 

 in yield under these nietliods of culture are comparatively small. 



Experiments with leguminous green forage crops on poor soils showed the 

 value of adding held peas, vetches, and other leguminous plants to mixtures of 

 forage crops for the purpose of increasing the yield of green forage and of 

 grain and of improving their quality. 



Report on culture experiments at the Norwegian Agricultural High School, 

 1914-15, S. Hasund and P. Borgedal (Ber. Norges. Landhr. Hoiskolcs Jordkltr. 

 Forsijk, 1914-15, pp. 1-22, 31-54). — The extension of cooperative field crop ex- 

 periments in 1915 is pointed out, and the results of a number of these experi- 

 ments are reported. 



The average results of 81 cooperative fertilizer tests with nitrate of soda 

 and sulphate of ammonia showed that the unit of nitrogen in sulphate of 

 ammonia represented from SO to 90 per cent of the value of the unit in nitrate 

 of soda. In other cooperative tests the action of lime was found quite marked 

 the first year on soil either unfertilized or fertilized with barnyard manure, 

 while on soil receiving commercial fertilizers the effect of lime was unim- 

 portant the first year but much more striking the second and third years. 

 In a cooperative series of 67 tests with lime, potatoes were not found bene- 

 fited by its use, while meadows, as shown by 4-year experiments, gave an in- 

 crease of 5.6 per cent in the yield of hay and barley fields of 4.4 per cent in the 

 yield of grain as apparently due to lime treatment. A larger increase from 

 liming wa.s secured with unfertilized than with fertilized crops of barley. 



Cooperative subsoiling tests in connection with the culture of different crops 

 gave varied results and did not allow drawing general conclusions. 



[Experiments with field crops], A. Sjostrom {Red. Ultuna Landtbr. Inst. 

 [Sweden], 1915, pp. 4^-52). — The results of cultural and variety tests with 

 cereals and root crops are briefly reported. Petkus rye sown at three different 

 rates gave practically the same yields' of grain and straw from the three differ- 

 ent seedings. The differences in yield resulting from sowing Hannchen barley 

 on the first, fifth, and twentieth of INIay, as well as from pulverizing the soil 

 to depths of 3, 5, and 7 cm. (1.2, 2, and 2.8 in.), were also insignificant. 



In a test of soiling crop mixtures the best yield in the green forage cut July 

 22 of dry matter and nitrogen, 4.6 tons and 83 kg. per hectare (4.1 tons and 

 .73.8 lbs. per acre) respectively, was secured from a seed mixture consisting of 

 120 kg. of oats, 175 kg. of field peas, and 40 kg. of vetch per hectare. Analyses 

 made of a part of the crop allowed to ripen and harvested September 8 showed 

 that the dry-matter content had almost doubled since July 22. 



In another experiment Petkus rye harvested and analyzed at weekly interval? 

 from June 1 to July 7 continued to increase in the yield of green forage until 

 June 22. The dry-matter production continued to increase and at the close of 

 the test was found to be four times as great as at the beginning, the average 

 weekly increase being 940 kg. per hectare. The a.s^h and nitrogen content con- 

 tinued to increase up to June 22. 



Crops of a seed mixture consisting of 110 kg. of oats and 160 kg. of vetch 

 per hectare and harvested weekly from July 7 to August 17 showed a continued 

 increase in dry-matter during the period, with the exception of the last two 

 weeks, when this factor remained constant. The percentage of vetch in the 

 yield of the crop mixture increased from 23 to 50.1 per cent during the ex- 

 periment. 



Turnips, swedes, and field beets grown in comparison produced 85.8, 70.3, 

 and 62.2 tons of roots per hectare, respectively. The average weight per root 

 was 1.17 kg. for the turnips, 1 kg. for the swedes, and 0.69 kg. for the field 



