Influence of Potash on Herbage. 177 



species, were represented on plots 9 and 10, but on neither 

 was the total number much more than half as many as with- 

 out manure. On plot 9, receiving potash, the six grasses 

 which have become most prominent are (somewhat in the 

 following order) Poa pratensis, Agrostis vulgaris, Festuca 

 ovina, Dactylis glomerata, Avena elatior, and Holcus lanatus, 

 and they together average more than 80 per cent, of the pro- 

 duce. The seven most prominent grasses on plot 10, with 

 the discontinued potash, are Festuca ovina, Agrostis vulgaris, 

 Alopecurus pratensis, Avena elatior, Poa pratensis, Holcus 

 lanatus, and Dactylis glomerata, which together make up 

 about as much as the six on plot 9. The chief differences are 

 that whilst Alopecurus has much increased on plot 10, there 

 is scarcely any of it on plot 9 ; Holcus and Poa pratensis are 

 the less prominent on plot 10 ; Dactylis glomerata has 

 decreased on plot 10, but increased on plot 9 ; Festuca ovina 

 has considerably increased on both plots, but the more on 

 plot 10. Avena pubescens, Avena flavescens, Poa trivialis, 

 Bromus mollis, and Lolium perenne have almost disappeared 

 on both plots. Leguminous species represent only a small 

 fraction of 1 per cent on both plots. Miscellaneous species 

 have considerably decreased, more in weight than in number, 

 on both plots. 



On plot 9, with the continuous potash, the grasses showed 

 much tendency to produce stem and seed, and to mature. On 

 plot 10, with the potash discontinued, the proportion of leaf 

 to stem was very much greater, the herbage was patchy, of a 

 much darker green colour, and matured unevenly and imper- 

 fectly. There was, in fact, a relative plethora of nitrogen, 

 and with the deficiency of potash a deficient assimilation of 

 carbon. 



Comparing the results on these plots with those on plots 

 7 and 8, where mixed mineral manure alone, with potash and 

 without potash, was employed, it was noticed that on both the 

 ammonia plots (9 and 10) the produce was chiefly grami- 

 neous, containing scar3ely any leguminous herbage, and but 



