On Irrigation. 273 



exhausted, and run out into weeds and poverty ( 4 4 ). No- 

 thing else could be expected from such management. But 

 in other parts of Scotland, irrigation was not only practised 

 with considerable success ( 4 5 ), and for crops of grain, but 

 immense quantities of wild oats, formerly prevalent, were 

 completely extirpated, and for the destruction of which no 

 other means were known, previous to the introduction of 

 fallowing and of green crops ( 4 6 ). Water alone, however, 

 without the addition of other substances, will not bring 

 grain to perfection. Hence, though from year to year, it 

 may be applied to meadow and pasture grass with success, 

 yet it cannot be repeated with advantage to corn, except at 

 considerable intervals of time, or accompanied with ma- 

 nure ( 4 7 ). 



The system of irrigating for corn, seems likewise to have 

 succeeded in Somersetshire, where a large tract of country, 

 suffered to remain in pasture for two years, was, during that 

 time, at stated intervals, regularly flooded by a stream de- 

 scending from the adjacent hills. It was then subjected to 

 the following rotation of crops : 1. Wheat on the ley ; 

 2. Turnips; and, 3. Barley, with artificial grasses. The 

 produce of grain was very considerable, namely, of wheat, 

 from 40 to 50 bushels, and of barley, from 50 to 60 bushels 

 per statute acre ( 4 8 ). In a late publication on the utility of 

 water-meadows, a question therefore is not improperly put, 

 whether, upon particular soils, and under certain circum- 

 stances, irrigation might not produce similar effects upon 

 wheat, and several other plants of the field and the garden, 

 as upon herbage ? The author adds, that no good reason 

 can be assigned, why this valuable improvement should be 

 restricted to the cultivation of grasses ( 4 9 ). 



3. Plantations. It is recorded in the Statistical Account 

 of Scotland, that irrigation was in one instance used for a 

 very singular purpose. Captain Shand of Templand, in 

 Aberdeenshire, conducted water through his young planta- 

 tions, and found, that when done with judgment, it was the 

 cheapest and most effectual mode of encouraging the growth 

 of trees ( 41 ). To the alder, the willow, and even the birch 

 and the ash, it may be of use ; but unless in very dry soils, 

 it must be dangerous to forest trees. 



On the whole, the improvement of grass, seems to be the 

 great object to which the watering of land is peculiarly ap- 

 plicable. 



