Show WATER TO ALFALFA Furrows Method Is Confined to Comparatively Small Area It t Has Been Shown Water Is Rarely Distributed Evenly In Furrow Irrigation and Much Is Lost by Deep Percolation Alfalfa native meadows and anti grain are most commonly irrigated by one of ot the methods previously described rather than by the furrow method which Is the usual method of Ing orchards gardens root crops and vegetables The Irrigating or of alfalfa from rom furrows Is at present confined to o the Yakima valley Washington to of ot the Snake river valle valley in southern Idaho and to comparatively small areas in other states In the localities named the soil soli Is a fine clay loam Joam oam which runs together puddles when wet and bakes and cracks when dry Flooding the surfaces by any of ot the he customary methods tends to pud pud- dle die the top layer larer of soil soli which be becomes ie- ie comes quite hard when the moisture moistures Is s evaporated writes Samuel Fortier chief of irrigation United States department department de tie- of ot agriculture in Irrigation Age The and and baking processes pro pro- ceases Injure alfalfa and it was with the he object of keeping AS much as possible pos pos- sible ible of the surface dry that furrows were Introduced When a small stream streams Is s permitted 10 lo run in the bottom of a furrow for several hours the soil soli beneath be- be neath and for some distance on each side ide becomes wet while the surface may remain nearly dry The alfalfa grown in the Yakima valley alley In Washington is practically all Irrigated by means of ot furrows The grading is usually done by buck scrapers while a long rectangular drag removes most of ot the surface Inequalities inequalities inequalities In in- equalities that remain after the surface sur- sur face ace has been leveled roughly by the scraper craper The float is made of two 2 by y 6 G Inch timbers about twenty feet long ong held in position by crosspieces ot of f the same size six feet long The common practise is to run the furrows across the entre width or length of ot a field and In consequence thEir heir length varies from 20 rods to less ess In small smaIl fields to 80 rods in large fields As a rule the furrows are too long ong Farmers object to cutting up a afield afield field by head ditches but in a climate like Ike that of ot the Yakima valley in midsummer mid- mid summer ummer summer by far the most essential element element ele ele- ment In plant production Is lB water andall and all other considerations should give place to it It has been shown that water is rarely distributed evenly In furrow irrigation and that much Is lost ost by deep percolation To Increase the he the length of ot a furrow beyond feet teet or one eighth mile not only increases increases in in- creases the loss but renders s a uni uni- form orm distribution more difficult to se se- se- se cure Except in rare cases this distance dis- dis tance ance should be regarded as to the limit for the length of ot furrows In Inight light ight sandy soils soUse having a porous gravel stratum beneath the length may well 1 be reduced to feet A good method of ot dividing an ta fa a field for furrow irrigation is by placing lumber head flumes fiumes either 8 S by y 8 inches or G 6 by G 6 inches along the upper boundary of each strip Auger holes loles are bored through one side of the he flume fiume flush with the bottom at points joints where water is to be delivered to o the heads of ot furrows A short piece of lath revolving in a nail controls the flow from each opening On steep grades a cleat on the bottom of ot the Inside of the flume fiume nailed on crosswise Just below each opening will wm dam back the he water and increase the discharge When flumes are considered too costly the water Is di distributed among the furrows through wooden spouts set In the bank of an ordinary earthen ditch These head ditches when In operation are divided into a series serles of ot level evel spaces by means of drop boxes which hold the surface of ot the water at atthe atthe atthe the desired elevation The spacing of ot these drop boxes depends on the grade of or the head ditch and their cost averages about each Spouts are made usually by nailing together four lath ath There Is a special lath on the market somewhat heavier than the ordinary ordinary or or- dinar one used for plastering buildIngs build build- Ings being 05 inch thick two O inches wide and three feet long Four of these when nailed together cost about 35 cents and each spout in place Illace costs about 65 cents |