Land-Ditching, or Hollow-draining, is practised ch ief-ly in the counties of Essex and Hertford. It consists in digging both main and side-drains, similar to those generally adopted in draining land : the former are usually made from 22 to 24 inches, the latter from 20 to 22 inches, in depth. The soil is previously ploughed ; and the length to which the main drains may be protracted, without a vent, depends upon the situation of the land : when it has a regular declivity, the most proper method will be to carry off as much water as possible, by means of side-drains ; but, it the ground be irregular, it will be requisite to form additional main-drains, so that every advantage may be derived from the vallies, into which the latter must often be conducted to a considerable extent.
The length of the side-drains varies according to the elevation of the soil: in general, they need not be more than one rod apart from, each other; though, in very loose or porous grounds, they may be dug at a distance of one rod and a half. When the trenches are cut to a sufficient depth, they are filled up, and covered in the usual manner with straw and bushes. The expence of this method of draining is computed to be nearly 31. per acre.
Land-ditching not only carries ofF the water from wet or marshy soils, but also meliorates stiff loamy clays; which, being thus better enabled to resist the long-continuance of moisture on their surface during the winter, promote vegetation very early in the spring, and the grass is rendered of a superior quality. The weeds, etc. change their colour, and are totally divested of their rankness ; the corn also increases both in quantity and weight.—Another important advantage arising from this practice, is, that it will admit of the soil being ploughed at an earlier period of the spring, and later in autumn; while it may be tilled with greater facility, and kept clear from weeds at a very small expence.