PLANTS. 173 



roots can penetrate no farther into it unless reopen- 

 ed by new tillage." 



Tull's work was published a hundred years ago. 

 ft has been quoted and commented upon by most 

 of the subsequent writers upon agriculture ; and the v 

 facts above stated have never been controverted nor 

 doubted, either by these writers, nor, so far as we 

 have learned, by practical farmers. They are. there- 

 fore, undisputed. Why is it that cultivated crops 

 upon the margins of fields, and about stumps and 

 fast stones, give more dwarfish plants and less pro- 

 duct than the well-tilled portions of the field 1 It is 

 not owing to the poverty of the soil ; for these por- 

 tions abound most in the elements of fertility, by 

 reason of the plough, on being raised from the fur- 

 row, depositing there the finest and richest mould. 

 Why do meadows deteriorate 1 Is it not because 

 the roots of plants have not a sufficient range in 

 mellow earth to supply the requisite food ; and be- 

 cause the unbroken soil " becomes so hard and close, 

 that the weak sort of roots can penetrate no farther 

 into if?" 



There are some practical improvements which we 

 would draw from the preceding facts. And, 



First : In regard to the use of the plough in Indian 

 corn and other hoed crops. The roots of Indian 

 corn are known, from repeated observation, to ex- 

 tend in the soil at least six, eight, and ten feet ; and, 

 if planted in squares four feet apart, each hill has 

 virtually a pasture of four feet square to feed upon. 

 Now if the plough is run both ways through the 

 crop, this pasture is reduced to at least two square 

 feet, for the roots which furnish sustenance are 

 within reach of the plough, and must be cut by it. 

 Hence the plough, where it is employed, reduces 

 the pasture of each hill from sixteen to four square 

 feet, or three tourths. 



Secondly : In regard to the application of manure, 

 whether it should be applied in hills and drills, or 



