PRESIDENTIAL ADDRESS. 



n37 



popples, neither of which were prevalent in the adjoining arable fields; the 

 causes of this are under investigation. 



Thus, the movement in favour of ploughing up some of our grass land is 

 eminently sound. But sooner or later the organic matter now stored in the soil 

 will be much reduced, and trouble may then be anticipated. The difficulty 

 ought not to be insuperable ; the way out seems to be the North Country system 

 of alternate grass and tillage; leaving the land in arable cultivation for four or 

 five years, and then in grass for four or five years. 1 think that a few demon- 

 strations started on these lines in heavy-land districts would resolve many of 

 the farmers' doubts as to the advisability of breaking up some of their grass- 

 land. Some grass, however, there will always be on the clays, and the great 

 need is to improve it. Methods have been worked out in several places, and 

 thi-y should now be more generally applied. In most cases basic slag is sufficient 

 to "begin with, and it produces an improved herbage which may well repay 

 further treatment. 



We now turn to the loams. These present no special difficulties to be over- 

 come, but their productiveness is, of course, subject to all the usual factors 

 influencing plant-growth, viz., sufficient supply of water, air and plant 

 nutrients, proper temperature, root-room, and absence of injurious factors. 

 Water-supply, air supply, and temperature do not usually cause much trouble, 

 but the crop may be hampered by laclv of root-room, in which case periodical 

 deep ploughing or subsoiling may bring about a substantial improvement. It is 

 not necessary always to plough deeply; the point is to vary the depth, and once 

 in about four years to go deeply, so as to stir up the subsoil. On our land we 

 have done this for potatoes, and we found that subsoiling at a cost of a_bont 3.?. 

 per acre was followed by an increase of 10 cwt., worth 35s., in the yield per 

 acre. One of our neighbours does much more, and once in every five year.s 

 ploughs 17 inches deep with a steam plough: this is done in July, and the results 

 appear to be satisfactory. 



Once these great fundamental things have received attention, all these soils — 

 loams, sands, and clays — can be further improved by proper treatment with 

 fertilisers. A great deal of good work has been done on this subject, and the 

 results are steadily being diffused among farmers. 



When the results of field experiments are plotted they fall into two groups : — 



1. An increase in the fertiliser causes an increase in crop production, but 

 beyond a certain stage the increase falls off. This is especially the case with 

 nitrogenous fertilisers. 



The Rothamsted experiments with wheat give the following results : — 



In the Irish experiments carried out on a uniform scheme at a large number 

 of centres, when the quantity of sulphate of ammonia was varied, the yields of 

 potatoes were : — 



Standard Manure of Potash and Phosphates + 



