AGRICULTURAL TEXT-BOOK. 343 



a mora equal and probably a higher temperature and greater 

 command of moisture. A field plowed three or four inches 

 deep is easily exhausted; while such manures as are applied, 

 soon escape beneath the reach of the roots ; and, in many soils, 

 in process of time, the plow passing at one equal and shallow 

 depth forms an artificial and impervious /tard-pan. According 

 to Mr. Delafield in 1850, in Seneca county New York, &quot;The 

 evidence of every successive year, has clearly manifested the 

 economy and profit of deep tillage ; the mechanical operations 

 on the soil require less force and labor ; less seed is necessary ; 

 and all manures produce their full effect. Many of the best in 

 formed farmers are firm in the opinion that deep plowing and 

 subsoil plowing are more effective on wheat soils when a judi 

 cious system of drainage has been adopted ; for though deep 

 tillage by the plow allows the roots of plants to seek their food 

 at a greater depth from the surface, yet they will extend them 

 selves (in some soils,) to the cold influences of retained waters, 

 where drains do not exist, and be deprived of that full measure of 

 health and vigor which the principle of deep tillage is intended 

 to afford.&quot; 



The Jointer Plo&amp;gt;v, invented in Michigan, is forcing its way into very 

 general use. It is a miniature or small plow, which can be attached and 

 detached from the beam of any other plow at pleasure, and is placed a 

 short distance in advance of the main plow. It turns over 2 to 4 inch 

 es of the soil which is buried deeply and neatly under the furrow 

 formed bj the succeeding plow ; and with four oxen or horses, 10 to 12 

 inches can easily be reached (See Transactions of Michigan State A(j- 

 ricuttural Society, Vol,iv,p 147.) 



7 1 2. Horses cannot draw a plow for any very great distance 

 without stopping. A length of 250 yards is believed to be the 

 best for the size of a field, allowing the horses to rest at the 

 turning. The following table shows the quantities of land 

 plowed at different speeds, at given breadths of the furrow-slices. 

 (Stephen*,) 



