70 AGRICULTURAL STUDENTS J GAZETTE. 



might be the possible history of this field in remote times, what was its 

 original fertility, what it has lost of its fertility, and also what it has 

 lost during its half-century of wheat growing. I do not intend to take 

 any notice of those important ingredients in the soil, phosphoric acid 

 and potash, because they exist in much larger quantities than nitrogen ; 

 and also because we have the evidence that when salts of ammonia 

 have been applied to one of the plots which have received no mineral 

 manure since 1844, the crop has been all along and is at the present 

 time larger than the crops which has been manured every year with 

 minerals only. 



The history of the field as far back as we have any absolute record 

 begins in 1623, when a map of that date gives the area of the field, and 

 the hedges as they are at the present time. It was then in arable 

 cultivation and had a broad band of grass round three sides, with a 

 still broader piece of grass at the bottom ; hence probably its name of 

 "Broadbalk." It is by a comparison between the composition of the 

 pasture and the arable part of this field that I propose to get some idea 

 of the original composition of the soil ; but although we have evidence 

 that the exhaustion of the land by continuous wheat crops takes place 

 in the first, second, and third nine inches from the surface, I only intend 

 to refer to the first nine inches. The determination of the nitrogen in 

 the soil of the wheat field was made as early as 1846, but the figures 

 are not to be depended on, as at that time we did not possess the 

 accurate mode of sampling the soil which we employ later on. For the 

 purpose of my present paper I will make use of the analyses which 

 were made in 1865 and again in 1881. The quantity of nitrogen per 

 acre upon the upper nine inches of the soil of the unmanured land 

 amounted to 2,507 Ibs. and 2,403 Ibs., showing a loss in sixteen years 

 of 104 Ibs., or between 6 and 7 Ibs. per acre per annum. The nitrogen 

 in the first nine inches of the pasture at the bottom of the field amounts 

 to 6,200 Ibs. per acre ; and this amount does not differ very much from 

 that contained in the permanent pasture of the park or of a meadow 

 close to the wheat field. Even if we had not the actual evidence as to 

 the field having been in arable cultivation in 1623 we should have no 

 difficulty in deciding that such was the case ; for knowing what we do 

 of the farming of that period it would be impossible to attribute to any 

 other cause such a loss of nitrogen as has taken place since then. The 

 history of agriculture at very early periods gives us very little 

 assistance in endeavouring to trace what would be the character of a 

 soil when it was first taken into arable cultivation. Broderick, in his 

 work upon English land and English landlords, tells us that the soil of 

 England had been very little disturbed by the plough before the 

 invasion of Julius Caesar ; and he says further on, " the practice of 

 agriculture was an instinct and a tradition among the bodies of settlers 

 who formed Roman colonies, nine at least of which were established in 

 Great Britain." During the first four or five hundred years of the 

 Christian era, when the Romans occupied this country, their chief city 

 was " Verulanium," now St. Alban's. Possibly the site might have 



