Field Experiments on Root- Crops. 515 



taken up on the 24tli of November. The weight of clean roots 

 was: — 



At A, witli potasli-salts, lOj cwts., or 10 tons 10 cwts. per acre. 

 At B, without potash, 9 cwts., or 9 tons per acre. 



There was thus an increase of 30 cwts, per acre in favour of 

 the potash-salts. It is, however, proper to state that the ground 

 upon which the experiments were tried was very much injured 

 during the course of preparation by drenching rains, which fell 

 again and again at night, after it had been ploughed, and also 

 after it had been scarified ; there was, however, no alternative 

 but to sow the crop when the weather became dry, and make 

 the experiments under very unfavourable circumstances. 



The space above the line C D is a stiff clay, and here the 

 crop failed particularly. 



About 7 acres on the west side of the field was also very 

 much injured by frequent rains happening to fall during the 

 working of the land, and this, and this alone, appears to have 

 spoiled the crop, irrespective of any particular system of 

 manuring. On this space, 7 acres, about 15 tons of good rotten 

 dung, and 2|- cwts. of bone superphosphate were used per acre ; 

 the average weight of the crop was under 10 tons per acre, 

 whilst the space marked E received dung alone, and produced 

 fully double the weight of roots per acre, in consequence of the 

 land having been worked during finer weather, and having been 

 in excellent order when the seed was sown. 



The space F was also in a fine state of preparation, and pro- 

 duced as much again as the 7-acre piece, although it had only 

 a dressing of 5 cwts. of bone superphosphate per acre. 



The spaces A, B, C, D were first sown (May 22nd), and could 

 not be hoed for nearly a month. E and F were sown on the 29th and 

 oOth of May, and singled July 3rd. The experimental swedes sown 

 on the 22nd of May were only ready for singling on July 31st. 

 The fly attacked all the swedes most virulently on the badly pre- 

 pared land ; there were scarcely a sufficient number of plants 

 left for a crop, and some of these died away or became mere 

 abortions after being singled. On the experimental plot (l-20th 

 of an acre) there were 550 swedes of all sizes, weighing each 

 about 2 lbs. on an average. On the part not manured with 

 potash-salts there were also 550 plants. On both plots the 

 swedes ranged from the weight of a few ounces each up to 8 lbs. 

 200 swedes averaged about 4 lbs. each, whilst the remaining 350 

 were only about a pound each. Large and small roots were 

 mixed indiscriminately, irrespective of distance. Three swedes 

 standing together, or 15 inches apart, weighed nearly 7 lbs. each ; 

 other similar spaces contained mere nuts in size. Had the plants 



