374 
Field Experiments on Root- Crops. 
G. That the dung — which, it may be stated, was well rotten, 
and of a very superior character — gave by far the heaviest crop, 
and that nearly as good a crop of swedes was produced when, 
instead of 20 tons of dung only, 10 tons of farmyard-manure 
and cwt. of superphosphate were used. 
The soil of the experimental field was in a good agricultural 
condition, but of a light character ; and on such land well-rotten 
dung, apart from its fertilising effects, is particularly useful in a 
dry season, as it has a tendency to preserve the moisture in the 
land, and thereby sustain the life of root-crops better than 
artificial manures. On light soils I also find nitrate of soda, in 
combination with superphosphate and potash-salts, generally to 
be more beneficial to root-crops than sulphate of ammonia 
mixed with the same fertilisers. 
Experiments on Sivedes made hy Mr. Charles Hunter, in 1869, at 
Blennerhasset Farm, Carlisle. 
The same series of experiments was likewise kindly under- 
taken for me by Mr. Charles Hunter, who superintends Mr. W, 
Lawson's experimental farm at Blennerhasset, in Cumberland. 
The soil of the experimental field was a light gravelly loam. 
It was in turnips in 1867, and in oats in 1868. It was exposed 
in ridges to the action of the atmosphere during the winter ; 
the ridges were twice split in spring, the land harrowed down, 
and the manures sown broadcast. The soil was then ridged up 
and the seed sown on the 19th of May. 
The swedes were taken up on the 8th of November, topped, 
cleaned, and weighed, when the results exhibited on the next 
page were obtained. 
The 3 unmanured plots yielded respectively 12 tons, 145- 
tons, and 16^ tons of clean swedes; and there was, it will be 
seen, a difference of 4^ tons of roots per acre in the weight of 
the crop on plot No. 1 on one end, and on plot No. 12 at the 
other end of the experimental field, and of 2\ tons between Plot 
1 and the central unmanured plot. These differences in the 
produce of roots on the 3 unmanured plots are too great to be 
overlooked ; they seem to point out clearly that the field was in 
a poorer condition in one end than in the middle, and best at 
the opposite end. Unfortunately, this Avant of uniformity in the 
agricultural condition, and probably of depth of soil in the experi- 
mental field, vitiates in a measure the results of the experiments. 
Still, with all their faults, these field trials prove distinctly that 
superphosphate alone has not nearly so good an effect upon 
swedes on light land than mixtures of superphosphates with 
potash-salts. 
