AMERICAN INSTITUTE. 469 



This is not the case with lime— wherever agriculture has been 

 advanced, the presence of lime is indispensable — all classes of dry 

 soil are immensely benefited by its use — sandy, silicious, clay and 

 gravelly lands are almost barren if it is absent. All the analyses 

 of fertile soils tliat have come under my consideration, have uni- 

 versally shown lime to be present. If it is found in very small 

 quantity in the surface soil it will be abundant in the sub-soil, 

 because its nature causes it to sink. And notwithstanding it is 

 virtually necessary as a food for plants, still the quantity in a soil 

 need not be large, as a four years rotation of crops only carries off 

 about two hundred and forty pounds from an acre; but this quan- 

 tity is now indispensable to ripen and perfect cultivated plants, 

 and if not added artificially, infertility will undoubtetlly ensue. 

 It is often found in several states of combination, ar for example : 

 in chloride of calcium, which is soluble in water, and is detected 

 in the sap of plants; in sulphate, silicate, carbonate, and humate 

 of lime. I use from forty to two hundred bushels of shell lime to 

 the acre, and renew every six years, and have always found high 

 farming the most profitable, and land so tilled always grateful. 



The question is often asked whether green manuring will inva^ 

 riably prevent soils from becoming exhausted ? I answer, that 

 provided it is judiciously practiced, land may be secured from 

 exhaustion for an indefinite period of time, not by only plowing 

 under the green crop raised upon the same field, but that raised 

 on another, and spread upon it. Still the crop growing upon a 

 field may be advantageously turned under for a few years. Rye 

 I have found admirable for that purpose, because it is a sure crop, 

 grows rapidly in the spring, and covers the ground thoroughly. 

 When I use red clover, two crops are cut, and the third plowed 

 under in full bloom. You may alternate clover with a wheat 

 crop very advantageously without other manure for a, time ; but 

 notwithstanding that poor land may be brought to a remunerative 

 fertility, it will most assuredly go back to a state of nature, if it 

 does not receive sooner or later, saline matters in some shape. A 

 load of unripe dry straw will afford a far richer manure than ripe 

 dry straw, because in its partial green state it contains the sub- 



[Am. Inst.] 31 



