406 



THE SOUTHERN PLANTER. 



[July 



and dear that he uses as little as possible 

 for his purposes. Besides this considera- 

 tion, his climate is more suitable to grass than 

 to grain, and his other large crops are much 

 more generally broad-cast than tilled. 

 These are sufficient causes why, in general, 

 the culture of land in the Northern States 

 should be less exhausting than in the 

 Southern, without detracting anything from 

 the superior advantages which we of the 

 South enjoy, in the use of African slave- 

 labour. 



At the risk of uttering what may be 

 deemed trite or superfluous to many of those 

 who now honour me by their attention I 

 beg leave to state concisely, the fundamen- 

 tal laws, as I conceive them to be, of sup- 

 ply and exhaustion of fertilizing matters to 

 soils, and aliment to plants. 



All vegetable growth is supported, for a 

 small part, by the alimentary principles in 

 the soil, (or by what w^e understand as its 

 fertility,) and partly, and for much the 

 larger portion, by matters supplied, either 

 directly or indirectly, from the atmosphere. 

 More than nine-tenths usually of the sub- 

 stance of every plant is composed of the 

 same four elements, three of which, oxygen, 

 nitrogen, and carbon, compose the whole at- 

 mosphere. The fourth, hydrogen, is one 

 of the constituent parts of water; and, also, 

 as a part of the dissolved water, hydrogen 

 is always present in the atmosphere, and in 

 great quantity. Thus, all these principal 

 elements of plants are superabundant, and 

 always surrounding every growing plant; 

 and from the atmosphere, (or through 

 water in the soil,) very much the larger 

 portion of these joint supplies is furnished 

 to plants ; and so it is of each particular 

 element, except nitrogen ; much the small- 

 est ingredient, and yet the richest and most 

 important of all organic manuring substances, 

 and of all plants. This, for the greater part, 

 if not all its small share in plants, it seems is 

 not generally derived even partially from the 

 air, though so abundant therein, but from the 

 soil, or fiom organic manures given to the soil. 



But though bountiful nature has offered 

 these chief alimentary principles and in- 

 gredients of vegetable growth in as inex- 

 haustible profusion as the atmosphere itself, 

 which they compose, still their availability 

 and beneficial use lor plants are limited, in 

 some measure, to man's labours and care to 

 secure their benefits. Thus, for illustration, 

 suppose the natural supplies of food for 



plants furnished by the atmosphere to be 

 three-fourths of all received, and that one- 

 fourth only of the growth of any crop is 

 derived from the soil and its fertility. Still, 

 a strict proportion between the amount of 

 supplies from these two different sources, 

 does not the less exist. If the cultivator's 

 land, at any one time, from its natural or 

 acquired fertility, affords to the growing 

 crop alimentary principles of value to be 

 designated . as five, there will be added 

 thereto other alimentary parts, equal to 

 fifteen in value, from the atmosphere. The 

 crop will be made up of, and will contain, 

 the whole twenty parts, of which five only 

 were derived from, and served to reduce, by 

 so much, the fertility of the soil. These 

 proportions are stated merely for illustra- 

 tion, and, of course, are inaccurate. But 

 the theory or principle is correct; and the 

 law of fertilization and exhaustion, thence 

 deduced, is as certainly sound. 



Then, upon these premises, there is taken 

 from the land, for the support of the crop, 

 but one-fourth of the aliment derived from 

 all sources for that purpose. And, if no 

 other causes of destruction of fertility were 

 in operation, one green or manuring crop, 

 (wholly given to the land, and wholly used 

 as manure,) would supply to the field as 

 much of alimentary or fertilizing matter as 

 would be drawn thence by three other 

 crops, removed for consumption or sale. 

 But in practice there are usually at work 

 important agencies for destruction of fer- 

 tility, besides the mere supply of aliment 

 to growing crops. Such agencies are, the 

 washing off of soluble parts, and even the 

 soil itself, by heavy rains, the hastening of 

 decomposition and waste of organic matter, 

 by frequent tillage processes and changes 

 of exposure — and plowing or other working 

 of land when too wet, either from rain or 

 want of drainage. Also, a cover of weeds 

 left to rot on the surface, or any crop plow- 

 ed under, green or dry, as manure, is sub- 

 ject to more or less waste of its alimentary 

 principles, in the course of the ensuing de- 

 composition. Therefore it is nearer the 

 fiicts, that two years' crops or culture, for 

 market or removal, would require one year's 

 I growth of some manuring crop to replace 

 'and to maintain undiminished, or increas- 

 ing, the productive power of the field. 

 The poorest and also the cheapest of such 

 manuring crops, will be the natural or 

 " volunteer" growth of weeds on land left 



