200 



THE EOTHAMSTED EXPERIMENTS. 



Arrange- 

 ment of 

 plots. 



Method of 

 ascertain- 

 ing results. 



Description 

 of tables. 



three. That is to say, each of the three differently manured 

 plots is divided into four as above described, and as indicated 

 in the heading of the several tables ; and, as the same form of 

 table will, as far as possible, be adopted throughout, it is very 

 desirable that a clear idea of the arrangement should be 

 formed at the outset. It will be seen that under each of the 

 three main divisions designated in the heading according to 

 the manuring, the results are subdivided, showing first the 

 produce obtained where the roots were carted from the land ; 

 and secondly, where they were fed (or left) upon it. Lastly, 

 under each of these two conditions so far as the disposal of 

 the turnips is concerned, there is again a subdivision into 

 two — one where in the third year of the course the land was 

 left fallow, and the other where either clover or beans was 

 grown. 



Each year the amount of produce on each of the various 

 plots is weighed ; samples of each crop are taken ; in all the 

 dry substance and the mineral matter (ash), and in many the 

 nitrogen, are determined ; in many cases also complete analy- 

 ses of the ashes of the crops have been made. Lastly, deter- 

 minations of the total nitrogen have been made in the surface 

 soils, and in the upper layers of the subsoils, at different 

 periods ; and the nitrogen as nitric acid has also been deter- 

 mined to a considerable depth. As to the results themselves, 

 only brief reference to the main indications of these various 

 investigations can be made. 



Tables 56, 57, 58, and 59, give the amounts of produce of 

 the turnips, the barley, the leguminous crops, and the wheat, 

 respectively, in each of the eleven years in which each was 

 grown, in the eleven completed courses. Each table is divided 

 into three main divisions — the upper one giving the roots, 

 or the grain, &c, as the case may be ; the middle the leaves, 

 or the straw ; and the lower one the total produce — roots and 

 leaves, or grain and straw, together. 



Table 56 

 explained. 



The Swedish Turnip Crops. 



Referring to Table 56, relating to the Swedish turnips, it is 

 seen that in the first year, 1848, there was, both without 

 manure and with superphosphate alone, much more produce 

 than in any subsequent year; showing that, at the commence- 

 ment, the land was in somewhat high condition, due to pre- 

 vious treatment. Then, again, as already said, for the tenth 

 and eleventh courses, salts of potash, soda, and magnesia were 

 used as well as superphosphate. For these reasons, the results 

 of the first and of the tenth and eleventh courses are ex- 

 cluded from the averages to which attention will chiefly be 



