4 Experiments upon Swedes. 



or no more service* to the produce than inferior and all but 

 worthless manures. 



With a view of verifying these general conclusions, and ob- 

 taining at the same time information on some other points on 

 which I shall have to speak presently, I made the following 

 experiments. 



Part of a 40-acre field, marked Nos. 6 and 10 in the map of 

 the farm attached to the Royal Agricultural College, was divided 

 into 20 plots, of 8 poles each : 



No. 



1 was manured with farmyard-manure, at the rate of 20 tons per acre. 



2 20 tons of farmyard manure and 2 cwts. of superphos- 



phate per acre. 



3 3 cwts. of superphosphate. 



4 1 cwt. of superphosphate. 



5 6 cwts. of superphosphate per acre. 



6 3 cwts. of gypsum. 



7 2 cwts. of superphosphate and 1 cwt. of guano per acre. 



8 3 cwts. of Peruvian guano per acre. 



9 1 cwt. of sulphate of ammonia per acre. 



10 was left unmanured. 



1 1 was manured with 3 cwts. of bone-dust per acre. 



12 2 cwts. of sulphate of ammonia per acre. 



13 3 cwts. of dissolved bones per acre. 



14 ,, 1 cwt. of nitrate of soda. 



15 2 cwts. of superphosphate, 1 cwt. of salt, 40 Ibs. of 



nitrate of soda, and 40 Ibs. of sulphate of ammonia 

 per acre. 



16 3 cwts. of common salt per acre. 



17 3 cwts. of superphosphate per acre. 



18 3 cwts. of superphosphate and 1 cwt. of sulphate of 



ammonia per acre. 



19 3 cwts. of sulphate of potash per acre. 



20 3 cwts. of superphosphate and 1 cwt. of nitrate of soda 



per acre. 



The artificial manures were all finely powdered, and before 

 sowing mixed with red ashes (couch-ashes and burnt soil) at the 

 rate of 10 cwts. per acre. The manures mixed with the ashes 

 were sown on the 19th of May, and the seed (Liverpool or 

 Skirving's swede) on the 21st of May. The plants came well up, 

 but were eaten by the fly, and the field had to be resown on the 

 7th of June. Each experimental plot measured one-twentieth of 

 an acre, and comprehended 4 rows of drills of equal length. 

 The distance from drill to drill was 26 inches. The plants 

 were singled out 12 inches apart. Unfortunately the experi- 

 mental swedes, as well as the roots adjoining, after having 

 passed the ordeal of the fly, were afterwards attacked by a black 

 caterpillar, the black-jack,' as it is called here. Every exertion 

 was made to prevent the ravages of this pest, but without effect, 

 I .then tried to make good the bare places by transplanting 

 young swedes, and succeeded tolerably well ; but as I had to 

 repeat the transplanting of the roots several times when the 



