28 



THE CONTINUOUS GKOWTH OF LEGUMINOUS CROPS. 

 3. In rich Garden soil. 



Some account of this experiment is given in the 

 " Memoranda? and the results have frequently been 

 discussed more or less fully in various papers as 

 for example in Nos. 38, 51, and 60 ; but they are given 

 in more detail in No. 81. 



The experiment was commenced in 1854, and is still 

 in progress, so that this, 1891, is the 38th season of the 

 growth of red clover year after year on rich garden 

 soil. The plots are very small, so that estimates of the 

 amounts per acre, of the produce, or of the nitrogen in 

 it, can only be approximate. The crops are, however, 

 always weighed ; samples are always taken for the de- 

 termination of dry matter, ash, and sometimes nitrogen ; 

 and it is estimated that the amounts of produce were, 

 in the early years much more than, over the whole 

 period also more, and, even in many of the later years 

 as much as, is usually obtained on ordinary arable land 

 only once in 4, 6, or 8 years ; and the yields of nitrogen 

 in the crops are, accordingly, correspondingly large. 



Samples of the soil have also occasionally been taken, 

 and the results point to the conclusion that much of 

 the nitrogen of the clover crops has been derived from 

 the soil. 



The plot of land upon which these experiments are 

 conducted, is not transferred to the Trustees, but it is 

 very desirable that they should be continued until 

 decided failure is manifested. The crops should always 

 be weighed and sampled, as heretofore ; the dry matter 

 at once determined for the estimation of the crop ; the 

 ash also determined ; and samples reserved for " mixed- 

 crop " and " mixed-year " samples, for nitrogen deter- 

 minations, with a view to the estimation of the yield of 

 nitrogen in the produce. The soils were last sampled 

 in 1879, and it would be of interest again to take 

 samples and determine the nitrogen in them, before 



