30 GENERAL CONSIDERATIONS 



in the beds or be worked into the soil in the bottom 

 of the planting furrow. 



Tillage. — This term is employed for all those 

 operations by which the soil is stirred about grow- 

 ing plants. The word " cultivation " is often used 

 as the equivalent of tillage, but in reality it has a 

 broader meaning and covers not only this, but all 

 the other processes required in the production of 

 crops. Tillage is beneficial and for most crops posi- 

 tively necessary for the following reasons. First, it 

 kills weeds. This is its most obvious utility and un- 

 fortunately it is the only one that is understood by 

 many farmers. All plants that come up of their own 

 accord in cultivated fields or in grass lands are 

 termed weeds. In fertile soils, especially if care- 

 lessly tilled, they usually spring up in great numbers. 

 They are very harmful, especially when the crop is 

 young and small, since they not only rob it of the 

 needed plant food and soil moisture, but by their 

 ranker growth they crowd and smother it by shut- 

 ting out light and air. Killing weeds is thus an ab- 

 solute necessity. Careful farmers will always see to 

 it that all weeds are killed before they produce seed. 

 In this way in the course of a few years their num- 

 bers can be very sensibly reduced. 



While the killing of weeds is thus the most obvious 

 necessity for tillage, it is by no means its only or 

 perhaps its chief benefit. The roots of plants re- 

 quire air as well as moisture for their normal devel- 

 opment. Tillage breaks the hard crusts formed on 

 the surface of most soils after rains and allows the 

 oxygen of the air to enter it freely and also provides 



