236 Suggested Changes af Farming System. 



attraction, to be, of course, at once evaporated. Bach patch, then, 

 though only as big as half-a-crown, starves all the adjacent plants, 

 and as these plants are commonly thinly planted in the land, and 

 consist of the shallow-rooting ryegrass, it can easily be understood 

 why my field, well supplied with humus, and thickly shaded with 

 plants, many of them of deep-rooting character, remained luxuri- 

 antly green while those of my neighbours were dried up. 



Let me now briefly enumerate the other effects of humus. It not 

 only supplies nitrogen, but, as it decomposes, renders available 

 some of the phosphoric acid and potash of the soil. By keeping the 

 soil more open it aerates the land, and so sets free more plant food. 

 It enables the soil to retain manurial matter which would otherwise 

 leach away. This is particularly the case with ammonia, and it has 

 been found that a soil destitute of humus will contain scarcely any 

 nitrogen. The importance of humus to light soils is enormous, as 

 they are much less retentive of manure than heavy soils. By 

 keeping the land open humus enables superfluous water to drain 

 through the soil, and by keeping it more open prevents it being 

 soured. Air, moisture, and warmth, which are all so necessary for 

 the germination of seeds and the growth of plants, are but little 

 influenced by the chemical constituents of the soil, being all more 

 dependent on its physical condition, which can only be effectively 

 influenced by large quantities of humus, which, I may observe, can, 

 by us, be most cheaply supplied by deeply-rooted turf. It is 

 important to notice that, as a consequence of growing a deeply- rooted 

 turf, you can deepen the soil above and add to it below. In the case 

 of the Inner Kaimrig field, enclosed from the hill about seventy 

 years ago and never manured since, the ploughing depth had sunk 

 to about 6 inches. It is now about 9 inches, 2 inches being gained 

 above from the admixture of turf with the soil, and i below from the 

 action of the deep-rooting plants, and this depth can certainly be 

 added to as time advances. When growing a good deeply-rooted 

 turf, then, you wi^l not only be supplying much more and much 

 better food for stock, but you will derive from it, when ploughing 

 up, a long train of most valuable consequential results, which will at 

 once favourably influence anything you may subsequently grow, and 

 ensure that the utmost economy of production is arrived at. Perhaps 

 one of the most important results is that, through the agency of 

 deeply-rooted plants, and those with a large root system, you can, 

 and at no additional cost, most minutely and deeply till the soil. 

 The amelioration of the soil from root action is indeed most marked, 

 and our attention has been frequently called to it, and more especially 

 in the case of the Outer Kaimrig. When we ploughed our first turf 

 the work was of such difficulty that, in my " Agricultural Changes," 

 I suggested that it might be better to begin the rotation with rape, 

 in order that time might be given for the decay of the turf; but the 



