plots produced three qrs. per acre, and many of them were below 

 two. Naturally with these low yields the effect of the manurial resi- 

 dues was almost inappreciable. 



The trials of the new nitrogenous fertilisers were repeated, but 

 the yields in this field were all so low that much weight cannot be 

 attached to the results. Both the nitrate of lime and cyanamide gave 

 poor results, nitrate of soda being the most effective source of 

 nitrogen applied. 



For some years on the same field plots of mustard, vetches, 

 crimson clover and rape have been grown and ploughed in, in order 

 to ascertain which would have the best effect in preparing the 

 ground for a subsequent straw crop. The last straw crop was in 

 1907; the green crops were repeated during 1908 and 1909, and 

 wheat was again taken in 1910. After vetches a good yield of wheat 

 was obtained, in fact this plot, with 3^ bushels of dressed grain per 

 acre, yielded more wheat than any other experimental plot. As 

 in the previous trial the value ol the leguminous crops as a pre- 

 paration for wheat was very marked, the yield of grain being 60 per 

 cent, better after either vetches or crimson clover, than after rape 

 or mustard. The yield of straw was even more favourable to the 

 leguminous crops, and it was noticeable that on all these plots 

 following green manuring there was none of the blight which 

 characterised the wheat elsewhere. 



In the Laboratory, the pot experiments, in which the continual 

 growth of certain plants was compared with the growth of the same 

 plants in rotation, have been carried a year further. The results 

 are now being put together, but the experiment has been stopped 

 as the method adopted does not promise to yield any definite answer 

 to the question for which it was designed, i.e., What is the effect of 

 a plant upon the soil in which it grows whereby it makes the soil 

 less fitted to support a second growth of the same plant ? 



The experiments upon Clover Sickness have also been continued, 

 though no solution of the problem is yet in sight. 



The investigations on the effect of heating and of antiseptics 

 upon the fertility of soils, which were described in the last report, 

 have been continued. Some trials were made in the field, though 

 none of them yielded positive results, while other attempts towards 

 the practical application of the previous investigations have not yet 

 reached the stage for report. Mr. T. Goodey, M.Sc, of the Birming- 

 ham University, Mackinnon Student of the Royal Society, has been 

 working on the zoological side of the problem, and he and Dr. 

 Hutchinson have now accumulated a good deal of material regarding 

 the life history and numbers of the protozoa associated with the soil. 



