1919] FIELD CKOPS. 229 



from the nitrate used with the coinplele apr>]ication, but in tlie two preceding 

 years a sinj^le application appeare<l tlie more lirofitaltle. A similar experiment 

 with corresponding results was conducted with mangels, but in this case 150 kg. 

 of the nitrate were used. 



A comparison of Norwegian nitrate, anunonium nitrate, ammonium sulphate, 

 and lime nitrogen of German, Swedish, and Norwegian mamifacture was begun 

 in 1914 and complete*! in 1918. Swedish turnips and orchard grass responded in 

 general quite favorably to the use of the different substances, while sugar beets 

 and mangels responded very unfavorably, and oats, barley, and potatoes gave 

 intermediate results. In discussing these data the belief is expressed tliat the 

 sodiiuu of the nitrate of soda may have acted injuriously upon the Swedish 

 turnips and the orchard grass and favorably upon the sugar beets and mangels, 

 wliile it remained neutral witli reference to oats, barley, and potatoes. 



Experiments conducted for one year with superphosphate and Bornholra raw 

 phosphate used on different crops indicated that the raw phosphate had pro- 

 duced from 50 to SO per cent of the effect of the superphosphate on the basis 

 of the phosphorh- acid content of .the two substances. The raw phosphate was 

 most effective on lime-poor soils. 



In variety tests with different crops the following were the leading sorts: 

 Tystofte Small wheat II, Tystofte Prentice 2-rowed barley, Svalof Victory 

 oats, and Up-to-date and Richter Imperator potatoes. 



Of different methods tried for control of thistles deep plowing late in the fall 

 and subsoiling gave the best results. 



In connection with a rotation experiment in 191G, certain plats wei'e in 

 fallow while others were devoted to G-rowed barley, soiling crops, potatoes, 

 or turnips. In the fall of that year the entire series was sown to wheat and 

 rye, the wheat receiving barnyard manure and the rye superphosphate. In 

 the spring of 1917 one-half of eacli plat was given 100 kg. and the other 

 250 kg. of niti'ate of soda per hectare. Cropping as compared with fallowing 

 apparently reduced the yields of wheat and rye to a marked extent, the greatest 

 reduction being after G-rowed barley and the smallest after potatoes or turnips. 

 A comparison of the total production for the two years with the plats in fallow 

 showed the following average increase in the production of feed units per 

 hectare where the smallest quantity of nitrate of soda was applied ; 6-rowed 

 barley plats 2,480, soiling crop plats 2,510, and potato plats 4,331. On the 

 plats receiving 250 kg. of nitrate of soda tlie corresponding increases were 

 2,071, 2,GG9, and 4,4U7 feed units, respectively. In another similar experiment, 

 the largest increase in pro(hiction of feed units per hectare was also in favor 

 of the plats which had produced the root crops. 



Culture experiments conducted with wheat crops showed that plantings made 

 April 10 gave better yields than plantings made April 23. Mangels thinned at 

 the proper time gave a yield 8.800 kg. greater than that secured from a plat 

 11 days later, and plants thinned to 24 cm. apart in the row gave a yield greater 

 by 800 kg. per hectare than the yield from plants thinned to 30 cm. apart as 

 compared with greater distances between plants and later planting. Chicory 

 produced the best yield when set about 4 in. apart in the row on April 28. 

 Turnips grown for seed and not thinned did not produce as large a yield as 

 when derived from those thinned to 6 in. apart in the row. Cutting back 

 Swedish turnips to two-thirds their actual size about June 1 caused a marked 

 reduction in yield. Covering the rows on February 12 with seaweed at the rate 

 of 20 loads per tondeland (1.36 acres) increased the yield by about one-third. 



Tests with different grass and clover mixtures resulted in the best yields, 

 even the first year, from a seed mixture of 6 kg. of red clover and 16 kg. of 



