FALLOWING. 57 



4th. Clay and calcarious soils, require less watering 

 than others. 



5th. Irrigation is of less importance in northern than 

 in southern latitudes : and, 



6th. In cold climates, or in situations of much eleva- 

 tion, irrigation is most usefuilj employed in the spring 

 and autumn ; and in hot climates and sandy soils in the 

 summer. 



Where a good head of water can be made without too 

 great an expense ; or where a brook, or part of a river, 

 can be so diverted from its course, as to be made to 

 spread its waters over the neighbouring grass grounds, 

 it should be attended to, as a matter of no small impor- 

 tance. The means of watering the ground, or of taking 

 it off, should be completely under controul ; for, if too 

 much be suffered to run on, it may do more hurt than 

 good. The quantity should be proportioned to the na- 

 ture of the soil; as sandy grounds require more, and 

 stiff soils less. The channels should be so made as to 

 carry the water to every part, except where the ground 

 is naturally wet. The main channel should just have 

 descent enough to cause the water to run ; and the late- 

 ral branches should be run in such directions as that the 

 descent be very moderate, and at the same time convey 

 the water to every part of the ground. Sometimes it 

 is necessary to carry off the surplus water by other 

 channels, where the ground has little hollow through it. 

 When the weather is hot, the water should be taken 

 off the ground. The night, and days which are cool 

 and cloudy, are the best times for applying it. In the 

 spring, it should not be applied till the ground is some- 

 what dry; and after the grass begins to start let the 

 quantity be diminished, and let it also be stopped during* 

 rainy weather. When the grass is pretty well grown, 

 no water should be applicfl, except in cases of drought. 

 After taking off the second crop, the water may be 

 thrown on more plentifully : but it mist be taken off some 

 time before the winter frost com'nences. Mr. Van 

 Rensselaer considers a month, a suficient time to let it 

 remain on in the fall. 



It is the easiest and cheapest mode of fertilii'Ing poor 

 land. It promotes a perpetual fertility without tiie ex- 

 pense oi manare. It may be made to vield t'le greatest^ 

 6* 



