506 Field Experiments on Boot-Crops. 



3. It is difficult, however, to understand why the addition of 

 superphosphate to half the quantity of dung-, which was placed 

 on plot 1, should reduce the crop as much as it did. There can 

 be no doubt about the accuracy of the result, and it is therefore 

 placed on record as an example of the curious and unexception- 

 able anomalies which so frequently puzzle the experimenting 

 agriculturist. 



4. The crude potash-salts on plot 5, it will be seen, had a 

 very good effect, for they gave an increase of 3 tons 5 cwts. of 

 roots per acre. 



5. Exactly the same increase was obtained when the potash 

 salts were mixed with superphosphate. The addition of the 

 latter, one would have thought, should increase the produce 

 beyond what the salts used alone gave, but the result was other- 

 wise. It appears, however, that superphosphate, when combined 

 with ani/ of the other manures, produced a remarkable increase 

 in the weight of the tops, which may have been prejudicial to 

 the development of the bulbs, the ainount of available soluble 

 fertilising matters in the mixture of dung and superphosphate, 

 and in the mixture of potash-salts and superphosphate being 

 excessive, and causing the roots to run too much to top. I have 

 noticed before that soluble saline matters had this effect, though 

 not in all seasons ; and it appears to me, therefore, advisable to 

 apply readily soluble fertilising matters in moderate quantities 

 to root-crops. 



6. Common salt appears to have done rather harm than good 

 in these experiments, for the salted plot gave 2 tons 3 cwts. 

 7 stones and 21 bs. less swedes than the portion of the field which 

 received no manure whatever. 



7. The addition of superphosphate to common salt had a 

 much better effect than salt alone, but the increase in the crop 

 was not equal to that obtained by potash salts and super- 

 phosphate. 



Crude German potash-salts applied alone or in conjunction 

 with superphosphate, had a decidedly better effect than common 

 salt. The large increase produced by the German salts alone 

 certainly speaks favourably for the use of potash manures for 

 roots grown on light land, and encourages further trials on such 

 land. 



Experiments on Swedes in 1865. 



The same plan of manuring as that laid down for 1864 was 

 again adopted in 1865. The summer, however, was, if anything, 

 even more unfavourable for the cultivation of root-crops than 

 that of the preceding^year. The results then obtained cannot 



