48 



The determinations of nitrogen by soda-lime in the 

 surface soils consistently show, as before, a higher per- 

 centage where clover had grown than where only barley 

 had grown. As in the case of the subsoils from other fields, 

 the natural irregularities were such that the differences 

 in the amounts of nitrogen by soda-lime in the subsoils 

 of the differently cropped portions cannot be referred to 

 the differences in crop history ; but, as before pointed 

 out, the significance of the difference in the amounts of 

 nitrogen as nitric acid at the different depths is much 

 less affected by the natural irregularities of the subsoil. 



The cropping and manuring of this field are still 

 arranged more or less with a view to provide data in 

 reference of the alternation of clover with a cereal, and 

 the amounts of crop are, accordingly, always deter- 

 mined. Owing, however, to the foulness of the land 

 during the growth, and after the removal, of the barley 

 crop in 1890, it was decided to work it, and clean it 

 as far as possible in the autumn, and leave it for 

 summer fallow cleaning in 1891. It is proposed to 

 re-sample the soils of the different plots (especially for 

 the determination of nitrogen and nitric acid), in the 

 autumn of 1891 ; to sow barley and clover on all four 

 plots in 1892 ; again to sample the soils after the 

 removal of the clover in 1893 ; and then probably to 

 discontinue the experiment altogether. 



The results of the experiments above described have 

 not been made the subject of a separate report, but 

 abstracts of the numerical results have been given in 

 several papers, and their interest and significance 

 pointed out. (See Nos. 38, 51, 60, 67, and 81.) 



XII. EXPERIMENTS ON THE AMOUNT, AND ON THE COM- 

 POSITION, OF EAIN, AND OF LAND-DRAINAGE WATERS. 



The rainfall has been collected and measured at 

 Kothamsted, almost from the commencement of the 

 field experiments ; for more than 38 years in a gauge of 

 one-thousandth of an acre area, also in an ordinary 

 funnel gauge of 5 inches diameter; and, commencing 



