PRESIDENTIAL ADDRESS. 371 



sulphate of ammonia had distinctly more influence in the first five than in the 

 last five years, and this not only when used alone, but also when it was added 

 to phosphates only, to potash only, or to phosphates plus potash. It would 

 appear, therefore, that here at least — and there must be many other instances — 

 the persistent use of phosphates has not only not tended to exhaust the soil 

 of nitrogen, but has positively increased it. By way of measuring the extent 

 of the stored-up fertility in grass land that has been treated with phosphates, 

 I carried out a series of pot experiments on the following lines : Five lots of 

 soil and turf from treated and untreated land from the same fields were placed 

 in pots in which five crops of cereals and mustard were subsequently grown, when 

 it was found that on the average the yield was increased by 27 per cent. This 

 result was quite in conformity with the increase of nitrogen in the soil as 

 disclosed by chemical analysis.-' 



Turning now to the improvement of pastures, as contrasted with meadows, 

 it may be remarked that while no sharp line can be drawn between these two 

 classes of grass land in respect of ameliorative treatment, there are certain 

 distinctions which must be kept in view. In a meadow the plants are allowed 

 to grow up to full maturity, whereas in a pasture they are cut over daily, or at 

 least very frequently, by the grazing of the animals. It is difficult to arrive 

 at a decision as to whether a larger gross weight of dry material is got from a 

 given area treated as pasture, in contrast to being hayed, but the probability 

 is that the aggregate quantity is greater. Take the analogy of a patch of 

 lucerne. Cut three or four times in the season it may yield six tons of dry 

 matter per acre, cut once it would certainly yield much less. Or take the case 

 of cocksfoot ; this springs so quickly in the aftermath that the foliage may shoot 

 up six inches almost in as many days, whereas there would be no such growth 

 were the hay not cut over. It is a matter of observation, too, how quickly 

 red clover springs up after cutting, and trees and shrubs which may be grow- 

 ing only a few inches annually when unrestrained may send up stool shoots 

 several feet in length if cut over. It is difficult, however, to bring the question 

 to the test of figures. I have tried to do so by cutting over an area at short 

 intervals by means of a lawn mower, but the presence of extraneous matter, 

 especially worm-castings, vitiated the results. 



If there is any doubt as to the grjCater weight of dry matter produced under 

 a system of grazing, there can be none in respect of its digestibility. This 

 would appear to be the reason why sheep and cattle will fatten on a pasture, 

 whereas the animals would only remain in store condition on the herbage if made 

 into hay. 



At one time experiments on the improvement of pasture took the form of 

 temporarily enclosing an area, to which different methods of treatment were 

 applied and of determining the results in terms of hay. Supplementary to such 

 quantitative determination, chemical analysis and botanical separations were 

 often made, but it is evident from the work of the investigators already quoted 

 that the results so obtained may be a very unreliable index of the feeding value 

 of the herbage. In any case the competition between the various classes of 

 plants may be very different in a hay field and in a well-grazed pasture. Again, 

 in a hay field the produce is reaped and cleared off with all the plant food which 

 it contains. In a pasture, on the other hand, there is the daily conversion of 

 vegetable substance into manure and its immediate return to the land. Reflec- 

 tions of that sort induced me in 1896 to arrange a series of experiments where 

 a direct appeal was made to the animal. We all know that in a lot of animals 

 there are certain individuals which possess idiosyncrasies which result in their 

 thriving better or worse than the others. By careful selection, however, and 

 especially by keeping them under observation for a probationary period, this 

 objection may be largely eliminated. The greater the number of animals the 

 more completely is any disturbance due to individual peculiarities got rid of. 

 and for this reason sheep are usually employed in preference to cattle. No one 

 who looks into the details of these ' manuring for meat ' experiments can doubt 

 that, not only in broad outline, but even in the finer details, the results are per- 



°' ' Accumulated fertility in Grass Land in consequence of phosphatic 

 manuring,' Jour. Board of Agric, September 1914 and March 1916. 



