Field Experiments on Root-Crops. 



507 



therefore be relied upon as a good general guide ; indeed, my 

 swede experiments turned out more or less complete failures ; 

 I therefore give only one series, that tried by my friend Mr. 

 Robert Vallentine, near Leighton Buzzard, on a light sandy soil, 

 as an illustration of the difficulties with which the field experi- 

 menter has to contend, and on account of the useful practical 

 remarks which accompanied Mr. Vallentine's report : — 



" ExPEEiMEXTs witli ARTIFICIAL and Farmyard-Manures at Burcott Loige 



Farm, Bucks. 



Plots nn of an Acre each. 



jSTo. I 



Farmyard-manure 1 ton 



JFarmyard-manure \ ton ^ 



(Mineral superphosphate 22^ lbs.* . . . . / 



Mineral superphosphate 22^ lbs 



Nothing 



Crude salts of potash 22^ lbs 



Common salt 22 J lbs 



(Mineral superphosphate 22^ lbs "1 



I Crude salts of potash 22 J lbs j 



("Mineral superphosphate 22 j lbs. . . 

 \Common salt 22^ lbs 



" The experiments were tried in the middle of a field of light 

 sandy loam, to which no farmyard-manure had been applied for 

 fourteen years. Each plot contained 3 rows of about 5 chains 

 in length. Ridges were first formed, and then rolled down, so 

 that the manure might not be placed too deep. The land was 

 ridged, the manure and seed sown within the space of two hours, 

 on the 17th of May, with Sutton's Swede ; elevation of field 

 above the sea-level about 500 feet. The ground was moist when 

 the seed was sown, and was rolled down almost immediately. 

 No rain fell till nearly a fortnight afterwards, when, although 

 the quantity was considerable, it fell so rapidly that a very large 

 proportion ran off the land by the channels between the ridges 

 which were formed down hill. After this there were but slight 

 showers before the period of protracted drought set in, by which 

 time all the turnips began to suffer from mildew, from which 

 the crop never recovered. The crop was singled on June 30, 

 when the plants were large. The most forward plants, when 

 singled, were those after superphosphate alone, mixed super- 

 phosphate and crude potash, and nothing; the potash and com- 



* Equivalent to 4 cwts. per acre. 



