HORTICULTURAL LABOURS ON THE SOIL. 231 



the first time, the whole of the soil turned over should be equally mixed 

 together, manure or compost being added and incorporated at the same time. 

 When the ground of a kitchen garden has been originally trenched in this 

 manner to the depth of three feet, a fresh surface may be exposed for cropping 

 every year, by the following practice, recommended by Mr. Nicol : " Take 

 three crops off the first surface, then trench three spits deep, by which the 

 bottom and top are reversed, and the middle remains in the middle ; take three 

 crops off this surface, and then trench two spits, by which the top becomes the 

 middle, and the middle the top ; and take also three crops off this surface, and 

 then trench three spits, by which that which was last the middle, and now- 

 top, becomes the bottom, and that which is now the bottom, and was the 

 surface at first, now becomes surface again, after having rested six years. 

 Proceed in this manner alternately, the one time trenching two spits, and the 

 other three ; by which means the surface will always be changed, and will 

 rest six years and produce three." (NicoTs Scotch Gardener , 2dedit., p. 202.) 

 536. In the operation of trenching, when the object is to reverse the surface, 

 the firm soil is loosened, lifted, and thrown into the trench in strata, which, 

 when completed, will hold exactly the reverse positions which they did in 

 the firm ground ; but when the object is to mix the soil throughout, or when 

 the surface soil is to be kept uppermost, the face of the surface of the moved 

 ground must be kept in a sloping position, hi order that every spitful thrown 

 on it may be deposited in the proper place, with a view to mixture. The 

 simplest and best mode of trenching, with a view to this object, and provided 

 only one man is to be employed for every other object of trenching, is to line 

 out the ground into an even number of strips of three or four feet broad ; to 

 open a trench at one end of one of the corners of the plot, and to proceed from 

 one end to another of the strips till the whole plot has been gone over. This 

 mode saves much wheeling of soil, and where the plot is already level, and 

 care is taken to leave no firm ground between the strips, it is then unobjec- 

 tionable. Where the spade only is used in trenching, the operator stands on 

 the surface of the firm ground ; but where the pick is rendered necessary, he 

 for the most part stands in the bottom of the trench. " Ridge trenching" is 

 the term applied when the surface of the moved soil, instead of being smoothed 

 and levelled, is laid up in the form of a ridge, in order to benefit by exposure 

 to the atmosphere. Whatever mode of trenching may be adopted, it is of 

 great importance that the bottom of the trenches should either be level, or form 

 one or more regularly inclined planes, in order to carry off the superfluous 

 water of the surface soil. In a very retentive subsoil, if the bottom is 

 trenched irregularly, the places marked a, &, c, in fig. 160*, would retain 



Fig. 160* Section illustrative of food and bad trenching. 



stagnant water injurious to the roots of trees, c. ; but if the bottom were 

 loosened so as to form a regular slope, as from d to e, the water would 

 gradually follow that direction. 



537. Forking soil is simply stirring the surface with the broad-pronged fork, 

 (fig. 84, in p. 135,) which is greatly preferable to the spade for working among 

 the roots of growing crops. For working with litter or dung, the 'forks with 

 round-pointed prongs are used ; the rotundity of the prongs diminishing fric- 

 tion, both in inserting the fork in the dung, and in discharging the forkful. 



