I860.] 



THE 



SOUTHEKN PLANTEK. 



473 



Second. — Land once improved by irriga- 

 tion is put into a state of perpetual fertility, 

 without any occasion for manure or trouble 

 of weeding, or any other material expense. 



Third. — It becomes so productive as to 

 yield the largest bulk of hay, beside "abun- 

 dance of the very best support for ewes and 

 lambs in the spring, and for cows and other 

 cattle in the autumn of every year. 



Fourth. — In favorable situations, it pro- 

 duces very early grass in the springy when 

 it is doubly valuable. 



Fifth. — Not only is the land thus render- 

 ed fertile without having any occasion for 

 manure, but it produces food for animals, 

 which is converted into manure, to be used 

 on other lands; thus augmenting, in a com- 

 pound proportion^ that great source of fer- 

 tility. 



The subject of irrigation is one of im- 

 mense importance in a dry, arid climate, 

 such as characterizes portions of the western 

 plains particularly. It is paramount, and 

 may be employed throughout the continent 

 with advantages greater than any other ag- 

 ricultural application. It is an important 

 art of itself, and one that requires special 

 acquirements for its adaptation.* 



The direct action of tlie fertilizing con- 

 stituents of water are not the only influences 

 which that substance exerts upon our fields 

 and growing crops. Its simple percolation 

 through a soil has an important influence, 

 by displacing gases and thus creating circu- 

 lation of air and bringing a fresh supply of 

 ameliorating agents. 



A little reflection will teach us to prevent 

 the disastrous consequences of the sudden 

 and powerful rains that fall in our climate. 

 If the ground is cultivated shallow, we 

 must sufi'er from washing. A hill-side 

 plowed two or three inches would meet with 

 the same fate that we Would expect if we 

 were to expose an inclined looking-glass, 

 upon which we had sprinkled sand. The 

 deeper a soil is stirred the better rain will 

 will be absorbed, instead of running off"; 

 and the deeper the furrow the longer will 

 the moisture be retained. . The alternate 

 infl uence of showeis and sunshine upon 

 deeply-stirred land brings about another 



* See Stephens's Practical Irri;<ator, Smith's 

 Observations on Irrigation, Brown's Treatise on 

 Irrigation, Sir John Sinclair's Code of Agricul- 

 ture, Voyage en Es{)agne, par M. Jaubert de 

 Passa, Anieitung zum praktischen Ackerbau 

 von Schwerz, Lr. 1. 



(important effect, which cannot be obtained 

 without it : we allude to aeration — an influ- 

 ence of great importance, by which not 

 only the organic portions of the soil are, by 

 aid of air circulation, brought into a state 

 of decomposition; but gases are evolved, new 

 combinations formed, the inert mineral con- 

 stituents are also decomposed, new salts are 

 created, and numerous chemical actions take 

 place, producing active food for plant-life. 



It is, of course, necessary to distinguish 

 between a wholesome humidity and destruc- 

 tive saturation; while the one is to be che- 

 rished, the other must be avoided. On the 

 subject of under-draining we shall not enter; 

 its importance is too great for a cursory no- 

 tice in a paper of this kind, and we refer 

 our readers to the many valuable publica- 

 tions written upon the subject. 



Liebig makes the following beautiful re- 

 marks : 



" There is not to be found in chemistry a 

 more wonderful phenomenon, and which 

 more confounds all human w^isdom, than is 

 presented by the soil of a garden or field. 



" By the simplest experiment, any one 

 I may satisfy himself that rain water, filtered 

 through field or garden soil, does not dis- 

 solve out a trace of potash, ammonia, silicic, 

 or phosphoric acid. The soil does not give 

 up to the water one particle of the food of 

 plants which it contains. The most contin- 

 uous rain cannot remove from the field, 

 except mechanically, any of the constituent 

 elements of its fertility. The soil not only 

 retains firmly all the food of plants which 

 is actually in it, but its power to preserve 

 all that may be useful to them extends much 

 further. If rain, or rather water, holding 

 in solution ammonia, potash, phosphoric and 

 silicic acids, be brought in contact with the 

 soil, these substances disappear almost imme- 

 diately from the solution. The soil with- 

 draws them from the w^ater. Only such 

 substances are completely withdrawn by the 

 soil as are indispensable articles of food for 

 plants. All Others remain wholly or in part 

 in solution." 



In connection with this interesting sub- 

 ject, it may be remarked that the absorbent 

 power of soils varies according to their com- 

 position. It is greater in clays than those 

 which are silicious or sandy, but belongs to 

 all, more , or less, not excepting those of a 

 calcareous nature. Liebig tells us that if 

 the phosphate of lime be dissolved in weak 

 carbonic acid water, and the solution filtered 



