THE IEEIGATION AGE. 



Ill 



duits of about the same size and form began to take 

 their place. A machine laid these in a continuous 

 strip, little gates of galvanized iron at about every three 

 feet were imbedded in them; it cost ten to fifteen dol- 

 lars an acre, but it was well worth it. Evaporation 

 from the surface of water is of vejy little consequence 

 on any aqueduct, but many thought that it would pay 

 to save even this. So concrete pipes laid under ground 

 with small pipes rising above the surface to feed the 

 furrows came into use. Some iron piiies were fed from 

 stop cocks under pressure and were all right but for the 

 possibility of the head fluctuating from supplying other 

 consumers at the same time. A head measured into a 



Mr. H. L. Hollister, One of the Active Forces in the Twin Falls, 

 Idaho, Development. 



pipe flowing by local gravity only, without pressure 

 from any other source, will not fluctuate much. 



The number of furrows varied from five to seven 

 between two rows of trees, but six about a yard apart 

 made with two trips of a cultivator are about right. 

 If you can't make three at once with such a cultivator 

 comb the ground down until you can instead of re- 

 jecting the cultivator. From the effects of early flood- 

 ing it was plain that trees were injured by water 



touching the trunks, or rather standing there a few 

 hours. It was noticed first with oranges, but other 

 trees showed something of the same effect. The trial 

 of the small furrow system soon showed that the early 

 view was correct. Nowadays the water is not allowed 

 to come nearer than two feet and generally three or 

 over. One furrow was run beside a tree one year old, 

 two for the next and so on, coaxing the roots out into 

 the warm, rich top soil, but many put in all the fur- 

 rows for the young trees so as to get the roots out as 

 far as possible at the earliest moment. 



The regulation of the feed from these flumes is 

 primarily by the gates, which are always left in position 

 for the next irrigation. But when water begins to 

 run low in them the water is raised by brickbats or 

 cleats or something of the sort. The small discharge 

 holes are apt to clog with leaves and rubbish at first 

 and the best way to avoid that is a bit of curved pipe 

 four or five inches long inserted in the bottom of the 

 side and well below the water level, which should be 

 kept high purposely. When this pipe is turned so 

 that the lower end is toward the ground the discharge 

 is free and almost any rubbish is carried through by 

 the pressure. When it is turned half around so that 

 the outer end is upward it is above the water level in- 

 side and there is no discharge or inducement for float- 

 ing leaves, etc., to enter. 



When the ground is dry enough cultivation is at 

 once begun and continued in the best orchards without 

 intermission until the trees need water again. As soon 

 as the cultivator has finished going one way it is started 

 the other way, so that the top soil is kept like meal all 

 summer and is in perfect shape to furrow when the time 

 comes for the .next irrigation. Some have tried run- 

 ning a subsoil plow beneath these furrows so that very 

 little of the water shows above ground and less wets the 

 extreme top from which it is lost by direct evaporation 

 without reaching the roots. This works well on some 

 soils, though on others its utility is not obvious. It is 

 more a question of how much the roots may be cut 

 without injuring the tree too much. Some never plow 

 the orchard at all after the trees reach fair size, others 

 plow very shallow, most others depend entirely on the 

 cultivator, which is rarely run over five inches deep. 

 Where you find differences of opinion on these points 

 it is more a difference of soils or age of trees than any- 

 thing else. 



One would suppose that the upper side of an 

 orchard would show better results than the lower, be- 

 cause it gets water so much longer. But such results 

 are not apparent in a run of two or three days, though 

 the upper side must get more than the lower. To in- 

 sure thorough wetting of the lower ends of the fur- 

 rows a little is allowed to run over. But in many 

 orchards the work is so fine that this waste is practi- 

 cally nothing. In other cases a small patch of alfalfa 

 or something that needs little care is planted to take 

 up the waste. 



This system has been studied by experts from dif- 

 ferent parts of the west and is being adopted every- 

 where for fine fruit culture. What modifications there 

 are are only in the line of economy and do not affect 

 the principles which are simply: 



First That a small stream running a long time 

 does better work than anything that presses down the 

 soil or makes it muddy. 



