PECULIAR BENEFITS TO WHEAT, ETC. 171 



from rust, the most frequent and destructive of all its diseases. 

 This, much more than any other grain crop, seems to be especially 

 favoured by calcareous earth in the soil. The product is not only 

 always much increased, but other accessary effects are produced, 

 for want of which on the lands most highly manured, but still defi- 

 cient in lime, the wheat crop is made feeble, and in danger of great 

 loss or destruction from different disasters. Thus, if a heavy 

 growth of wheat is produced by putrescent manures only, the straw 

 is weak, and the crop is almost sure to be laid by its own weight 

 before ripening, even without stormy weather, and is very much 

 reduced in value. On limed or calcareous land, the crop is far 

 safer ; and is seldom laid, even when very heavy, unless by violent 

 storms, which is owing to the greater strength of the straw.* The 

 opening of the texture of close clay soils by the operation of cal- 

 careous manures, by permitting the better percolation of surplus 

 water, serves in some measure as drainage, and especially enables 

 wheat better to withstand the always redundant wet of winter on 

 such soils, which is much more the cause of " winter-killed" wheat, 

 than the severity of cold, or alterations of temperature. Wheat 

 also profits by the absorbent power of marled land (by which sands 

 acquire, to some extent, the best qualities of clays), though less 

 so than clover and other grasses that flourish best in a moist 

 climate. 



Indian corn does not need more time for maturing than our sum- 

 mers afford (except on the poorest land), and can sustain much 

 drought without injury, and therefore is less aided by these quali- 

 ties of marled land. Most (if not all) the different plants of the 

 leguminous or pod-bearing tribe, including all the varieties of clo- 

 ver, peas, and beans, derived such peculiar benefit from marling, 

 that it indicated some peculiar operation on these plants. What 

 this is, has recently been made clear by the researches of chemists. 

 The analyses of the ashes of leguminous plants show that they 

 contain very large proportions of lime, and far exceeding those of 

 any other cultivated plants. Of course, they need a larger and 

 ready supply of lime in the soil ; and they profit in proportion to 

 their wants, by such supply being furnished. 1845.] 



On acid soils, without heavy manuring, it is scarcely possible to 

 raise red clover ; and even with every aid from putrescent manure, 

 the crop will be both uncertain and unprofitable. The recommenda- 

 tion of this grass, as part of a general system of cultivation and 

 improvement, by the author of i AratorJ is sufficient to prove that 

 his improvements were made on soils far better than such as are 

 common. Almost every zealous cultivator and improver (in prospect) 

 of acid soil has been induced to attempt clover culture, either by 



* This effect is also affirmed by Johnston, p. 392. 



