662 Journal of Agriculture. [lo Nov., 1908. 



succulent fodder for stock during as much of the year as possible, and in 

 order that it may do this it is imperative that a large number of different 

 kinds of plants enter into its composition ; and these plants must have been 

 so selected that a suflficiency of early, medium, and late varieties is pro- 

 vided to supply a continuous succession of young leaves and shoots over 

 the whole paddock. If we examine any useful old pasture, natural or 

 artificial, we will always find that it consists not of one or two grass spe- 

 cies, but of several, and a like number of clovers, and in addition a num- 

 ber of other plants belonging to different genera. We may safely take a 

 lesson from nature's book, and make this condition our aim and ambition. 

 By using judgment it is in most mstances possible to secure a satisfactory 

 braird of well-mixed herbage, but the difficulty is to maintain it as such. 



Before proceeding to discuss the practical side of grass manuring we 

 will do well to review the results obtained by Lawes and Gilbert at their 

 famous Rothamsted Experimental Station. Their researches date from 

 1856, and have been conducted on about twenty different plots of mixed 

 herbage, occupying some seven acres in all. The soil is a stiff red loam, and 

 has carried grass continuouslv for as long as history relates. Up to 1874 

 the lattermath was grazed off by sheep, but since that time no stock have 

 been depastured there. A very complete series of manurial tests have 

 been carried out on these plots, and in summing up the whole question of 

 the influence of fertilizers on the character of the herbage, A. D. Hall, 

 Director of the Station, makes these pertinent remarks : — 



" The various species are differently stimulated by particular manures; 

 even among the grasses themselves such a difference of habit as a deep 

 or shallow root system will determine to which manure the grass will 

 respond. The aspect of any meadow represents the results of severe com.- 

 petition among the various species represented. The dominant species are 

 those most suited to their environment, that is to the amount and nature 

 of the plant food in the soil, the water supply, the texture of the soil and 

 other factors. If any of these factors be altered ... by manuring in 

 different fashions, the original equilibrium between the contending species is 

 disturbed ; some species are favoured and increase at the expense of the 

 others until a new equilibrium is attained, and the general character of the 

 herbage from a botanical point of view is completely altered. The fallacy 

 of the belief that grass land is not responsive to fertilizers is shown by a 

 glance at the unmanured plots, which have become sO' impoxerished that 

 weeds have come to form nearly 50 per cent, of the produce. On one por- 

 tion of this plot farm-yard manure was applied annuallv for the first eight 

 years at the rate of 14 tons per acre, and the good effects of it are still 

 to be seen in the yield — that is, after an interval of forty years ! " 



Nitrogen Only. — When nitrogenous manures were applied singly and 

 continuously, the effect was to squeeze the legumes out altogether. The 

 plot manured with ammonium sulphate became sour, and did not yield so 

 well as the nitrate of soda plot. The superiority of the latter is probably 

 due to the fact that it sinks deeply into the soil, thereby encouraging deeper 

 rooted plants, which axe better able to obtain moisture and nutriment in 

 times of drought. And further, the soda helps to make potash available. 



Phosfhoric Acid 'Only.- — On 'this plot the grasses and clovers have " run 

 out" to an even greater extent than on the unmanured plot. This illus- 

 trates the ultimate result of continuous single manuring. An occasional 

 dressing of phosphatic manure gives a striking result because plenty of 

 nitrogen and potash is lying latent in the soil, but when persistently 

 applied weeds usurp the place previously occupied by nutritious grasses. 



