Before concluding this chapter, we must say a few words in reference to flooded meadows. These will be found on the banks of the larger rivers or on streams of sufficient importance to be called rivers, as distinguished from brooks or streamlets. Here the flooding is caused by the water overflowing the banks, as the result of sudden thaws or an unusual quantity of rain. Here then the flood is not under control, and as it may happen at any and all times of the year, the grass may be spoiled by being covered with silt and drifted materials, or even the hay may be carried away by the flood.
These river flats, then, have seldom the requisites for carrying on irrigation, although the waters are of course more abundant than those supplied by the smaller streams; for even if we could by embanking so far control the water as to get it over the field when we might wish, yet alluvial flats like those of much of the Thames and Severn would not readily drain.
From facts like these it will at once be seen that there is a wide difference between irrigation and flooding; and we have hence endeavoured to separate what is too often confounded.
CHAPTER XIV.
ON THE LAYING DOWN OF PERMANENT PASTURE.
If we reflect upon the fact that much of the meadow of Great Britain is ribbed by the ridge and furrow of former arable culture, we shall conclude that the laying down of land to permanent pasture is an ancient no less than a modern process.
Formerly new pastures were made by sowing the collected seeds from a hayloft, but as in modern farming no one in his senses would let his grass get ripe enough for seed before cutting, present practice necessitates the mixing of such seeds as may be considered best in suitable quantities for our purpose. We shall have, then, in this place to consider:—
1. The preparation of the land;
2. The kinds of seed best adapted for different places; and
3. The after-treatment of the new meadow.