FIELD CROPS. 455 



Experiments in the preservation of barnyard manure by means of chemicals gave 

 negative results, and the authors recommend keeping manure moist and well packed 

 under cover, or using peat and soil to prevent deterioration. 



Green manuring with peas, beans, and vetches after summer or winter barley gave 

 good results with beets, but was less effective with potatoes. This result is consid- 

 ered due to the shorter period of growth of the potato and its lower nitrogen require- 

 ments, and also to the cultural conditions of the crop, which favor the accumulation 

 of available nitrogen in the soil during the vegetative period to a greater extent than 

 is the case with beets and cereals. 



A number of plats received no nitrogen, and although the experiments have been 

 in progress for several years the yields have not diminished, and the same quantities 

 of nitrogen have been taken up by the plants during the different years. Beets, 

 potatoes, and wheat have given comparatively high yields, while barley after the 

 beets, which draw heavily upon soil fertility, gave the lowest yield. 



For the Lauchstadt soil the following quantities of nitrogen per hectare are recom- 

 mended: For sugar beets (1) 60 to 75 kg. in two applications, either both in the form 

 of nitrate of soda or the first one as ammoniacal superphosphate, and if barnyard 

 manure was applied the year before the application should be a little less; (2) 

 40,000 kg. of barnyard manure and 200 kg. of nitrate of soda, or preferably 30,000 

 kg. of barnyard manure and from 200 to 300 kg. of nitrate of soda; (3) green manur- 

 ing and from 200 to 300 kg. of nitrate of soda. For potatoes (1) 45 kg. in the form 

 of nitrate of soda and ammoniacal superphosphate; (2) 30,000 kg. of barnyard 

 manure and, if the same is of jjoor quality, from 100 to 200 kg. of nitrate of soda in 

 addition. For winter wheat (1) 20 kg. of ammoniacal nitrogen given in the fall; (2) 

 the second spring after applying barnyard manure, a top-dressing of 100 to 150 kg. 

 ' of nitrate of soda, and the third spring a top-dressing of 200 kg. of nitrate of soda. 



For barley, the first year following a heavy application of manure no nitrogen 

 should be given; the second year 20 kg., and the third year from 20 to 30 kg. of 

 ammoniacal nitrogen should be applied. For oats, the second year after manuring 

 30 kg., and the third year 45 kg., partly in the form of ammoniacal nitrogen. A 

 top-dressing of sulphate of ammonia, especially on highly calcareous soils, was not 

 found beneficial, and the results indicated that, in order to prevent the loss of nitro- 

 gen through the volatilization of ammonia, this substance should be mixed with 

 ammoniacal superphosphate and worked into the soil immediately upon application. 



Phosphoric acid increased the yields but little and proved unprofitable when used 

 with barnyard manure. Heavy applications on plats receiving no barnyard manure 

 were also unprofitable, and it is concluded that, for beets and potatoes grown without 

 barnyard manure, from 50 to 60 kg., and for cereals, under the same conditions, from 

 40 to 50 kg. of phosphoric acid per hectare is sufficient for the particular soil. 



Potash was effective wherever the crops were grown without the use of barnyard 

 manure. Annual applications, however, are not recommended on account of the 

 injurious effect upon the mechanical condition of the soil which is likely to result. 

 Of the different crops the potato showed the greatest potash requirements. The fol- 

 lowing quantities of potash per hectare are recommended: Potatoes, 300 kg. of 40 

 per cent potash salt; beets, 300 kg. of 40 per cent potash salt, or from 800 to 1,000 kg. 

 of kainit; cereals, from 400 to 500 kg. of kainit. The potash in sugar-house refuse 

 was much less effective than that in 40 per cent potash salt. 



The roots of fodder beets removed the greatest quantity of potash from the soil as 

 compared with potatoes and sugar beets, the potatoes removing much more than 

 the beets. The leaves of the sugar beets contained more potash than the leaves 

 of the other root crops. On soil receiving only commercial fertilizers with no 

 potash, sugar beets removed 225 kg. of potash per hectare, and potatoes only 

 44 kg. This result shows that the sugar beet is better adapted than the potato 

 to the use of the potash in the soil, and it also explains why the potato has 



