6 



5. Surface Conditions. 



The best land for irrigation must have a uniform slope and be free from 

 ravines or depressions which increase the cost of the distribution system 

 and which are liable to be damaged by the accumulation of waste water. 

 Irregular slopes are difficult to irrigate. Land which is smooth is much 

 cheaper to prepare for irrigation. Slopes which are very steep can often 

 be well irrigated by running the furrows across the slopes. Very few 

 soils can be irrigated without excessive washing of the soil on slopes steeper 

 than 10 feet in 100 and usually the fall of furrows should be less than 2 

 feet in 100. The washing of the soil and in some- cases the leaching out of 

 the fertilizing salts from the upper part of the orchard may not be notice- 

 able at first, but the accumulation of this effect may do considerable injury 

 to the land. Steep slopes also have the disadvantage that they make culti- 

 vation, spraying and handling the fruit more difficult. 



6 . Drainage . 



The drainage of the soil is very important. The intending purchaser 

 who wishes to grow an orchard or other deep rooted plants should avoid 

 low lying lands. On a tract which is under a new irrigation system the 

 bottom land may be quite dry and the water table far below the surface. 

 The soil may be quite porous and underlaid with gravel. This may lead 

 to the belief that drainage conditions are very good. But with the exten- 

 sion of irrigation on the higher surrounding land, the drainage conditions 

 are often changed. The higher land is usually porous, absorbs water 

 readily and encourages a waste of water which is not always avoidable. This 

 effect, combined with the percolation losses from leaky ditches will cause a 

 .gradual rise of the water table, and unless there is a good natural drain 

 in the trough of the valley, the water table will soon rise until it is near 

 the surface and finally drown out the trees or plants. 



Land where the water table has not yet reached the danger height is 

 sometimes spoken of as sub-irrigated land and many advantages are 

 claimed for it, but as a rule this land will soon be injured by a continued 

 rise in the water table and should be avided for deep rooted plants 

 at least. 



While the higher lands are usually free from injury by water logging, 

 there are many instances where layers of hardpan may collect the water 

 and interfere with its downward percolation and cause a rise of the water 

 table too near the surface. 



The purchaser should investigate these conditions thoroughly and 

 examine the subsoil as well as the top soil by boring deeply with an auger. 



PREPARATION OF LAND FOR ORCHARD. 



1. Clearing the Surface. . 



Land to be irrigated is seldom heavily timbered and is generally free 

 from timber. To prepare land which is timbered the first operation is the 

 felling of the trees which are used for lumber or cut into firewood, the 

 value of which may partly pay for the cost of clearing. The removal of the 

 stumps is the next operation. This may be done by various methods, but 

 the process is always quite expensive. It may be done: First, By the hand 

 method with shovels, picks, mattocks and axes. Second, By the use of 

 stump pullers. Third, By the use of powder. Fourth, By the burning 

 method, which consists of boring auger holes at the foot of the stump into 

 which fires are built. Sixth, By the char pit method. This last method 

 which has been developed recently, has given very good results. The cost 



