394 LAND MAY BE SATURATKD WITH LIMK. 



than on such as are richer (Dr. Anderson.) This is also easily under- 

 stood, It is of poor soils in iheir natural slate of which Dr. Andersoa 

 speaks.* In this state they contain a greater or less quantity of organic 

 matter, but are nearly destitute of lime, and hence are in the most favour- 

 able condition for being benefitted by a copious liming. Experience 

 has proved that by ibis one operation such land may be raised in money 

 value eight times, or from 5s. to 40s. per acre ; but no practical man 

 would expect that arable land already worth £.2 per acre, could, by 

 liming or any other single operation, become worth MlQ per acre of an- 

 nual rent. The greater proportional improvement produced upon poor 

 lands by lime is only an illustration, therefore, of the general truth — 

 that on poor soils the efforts of the skilful improver are always crowned 

 with the earliest and most apparent success. 



5°. In certain cases, the addition of lime, even to land in good culti- 

 vation, and according to the ordinary and approved practice of the district, 

 produces no effect whatever. This is sometimes observed where the 

 custom prevails, as in some parts of Ayrsliire and elsewhere, to apply 

 lime along with every wheat crop (p. 384,) and on such farms especially 

 where the land is of a lighter quality. Where from 40 to GO bushels 

 of lime are added at the end of each rotation of 4 or 5 years, the land 

 may soon become so saturated with lime that a fresh addition will pro- 

 duce no sensible effect. Thus Mr. Campbell, of Craigie, informs me 

 of a trial made by an intelHgent farmer in his neighbourhood, where al- 

 ternate ridges only were limed without any sensibledifference being ob- 

 served. No result could show more clearly than this — that for one ro- 

 tation at least the expense of lime might be saved, while at the same time 

 the land would run the less risk of exhaustion. Another fact mentioned 

 by Mr. Campbell proves the soundness of this conclusion. The lime 

 never fails to produce obvious benefit where the land is allowed to be 4 

 or 5 years in grass — where it is applied, that is, only once in 8 or 9 

 years. The fair inference is, therefore, that in this district as well as 

 m others where similar effects are observed, too much lime is habitually 

 added to the land, whereby not only is a needless expense incurred, but 

 a speedier exhaustion of the soil is insured. Good husbandry, therefore, 

 indicates either the application of a smallerdose at the recurrence of the 

 wheat crop — or the occasional omission of lime altogether for an entire 

 rotation. The practical farmer cannot have a better mode of ascer- 

 taining when his land is thus fully supplied with lime — than by mak- 

 ing the trial upon alternate ridges, and marking the effect. 



Q^. On poor arable lands, which are not naturally so, but which are 

 worn out or exhausted by repeated liming and cropping, lime produces 

 no good whateverf (Anderson, Brown, Morton.) Such soils, if they do 

 not already abound in lime, are, at least, equally destitute of numerous 

 other kinds of food, organic and inorganic, by which healthy plants are 

 nourished, — and they are only to be restored to a fertile condition by a 



* " I never met," he says, " with a poor soil in its natural state, which was not benefitied 

 in a very great degree by calcareous matter when administered in proper quantities. But 

 I have met with several rich soils, which are fully impregnated with dung, on which lime 

 applied in any quantity produced not the smallest sensible effect." 



t " It is scarcely practicable to restore fertility to land, even of the best natural quality, 

 which has been thus abused ; and thia moorish soils, after being exhausted by lime, are 

 Bot to be restored." (IJrown.) 



