94 The Principles of Vegetable -Gardening 



(1) it gives different treatments to the land, the fault 

 of one year tending to be corrected by the manage- 

 ment in another year; (2) no one element of plant -food 

 is exhausted, the rotation tending to even up the 

 demands on the soil; (3) one crop leaves the land 

 in good physical condition for another ; (4) it incor- 

 porates humus; (5) it destroys pests and weeds; (6) 

 it economizes labor; (7) when green crops are turned 

 under, available or digested plant -food is incorporated 

 with the soil, and nitrogen may be supplied. The rota- 

 tion of crops means, also, rotation in tillage, manuring 

 and other treatment; and one of these may be quite as 

 important as the other. 



The philosophy of the "resting" of land is hereby 

 explained. It is not due to any need of recuperation 

 in the soil ; but the good effects which follow are the 

 compound results of the various benefits which are 

 derived from tilling and rotation. Gardeners find that 

 when soil becomes unproductive for a particular crop, 

 a change to some other crop may result in profit. 

 Soils which have been long kept in market- gardens may 

 be benefited by seeding down for two or three years. 

 Whenever possible, attempts should be made to prac- 

 tice some kind of a rotation in the market- garden area. 

 Now and then, a part of the land may be laid down to 

 clover for a year or two. 



2. THE FERTILIZING OF THE LAND 



When the soil has been thoroughly fitted and im- 

 proved by all the foregoing means, a gardener may 



