909 U. S. DEPARTMENT OF AGRICULTURE. FARMERS' BULLETIN No. 263. PRACTICAL INFORMATION FOR BEGINNERS IN IRRIGATION. BY S. FORTIER, IHRIGATION ENGINKER. WASHINGTON : GOVERNMENT PRINTING OFFICE. 1906. LETITR OF TRANSMITFAL U. S. DKI'AKIMK.ST OF AoRicin/n UK, Oi'i'ici: oi' l'-\ri'.iti\iKN r SIATIONS, \\Hsi,hnih»i, n. r., Jtihj .i, 1006. SIR: I hiivf thr honor to tiansinit hmnvith tlio iiiiimiscript for a FariUi'i's' Biillrtin, t,nviii<4 piactirnl int'onnation for l)r<^finn('rs in in'ii;!i- tion. pr«>|>i>r*'tl l>y S. I'\>rti«>r, tMij^iniMT in char^o of Irrigation InvoHti- ^utions of thir> ()llitM> in tho Pacitic diHtrict. There is a rfrout wave of emigration to tht* Wt^st and activity in canal construction, throwing open to settlement large an^is of land which must bo irrigated. The greater numlxu" of the settlers for these lands vv ill (M)mo from regions Nvh(M't' irrigation is not jtracticrd, und the whole system of agi'iciilflire whii h thiviniist j)ru< I ice will he new to them. In thi> paper Pi'o- fi' -oi l''orti('r has atttMnpted to bring together tin' information which will be most needed by these beginners in irrigation. Its publication as a Farmers' iiulletin is recommended. IJespe<l fully, A. C. I'ui i;. D'lrector. lion. JAMES WILSON, Stcntary. 268 (2) CONTENTS. Pago. Introduction 5 Selection and location of an irrigated farm 5 The water supply 7 Farm <litches 10 Capacity 11 Form 11 Grade 13 Plan and location 15 Structures 16 Preparation of land for irrigation 19 Removal of native vegetation 19 Methods uted in preparing land 20 Surface grading and field laterals 20 Preparing land for furrow irrigation 22 Preparing land for check irrigation 24 Preparing land for border irrigation 26 Preparing land for garden irrigation 26 Irrigating different crops 28 Alfalfa 28 < I rain 31 Potatoes 32 Fruit trees 33 Small fruits and vegetables 35 How to lessen the wast« of water 36 Right quantity of water to apply 37 Proper percentage of soil moisture 37 (Quantity to apply in one irrigation 38 Conclusions 39 263 (3) ILLUSTRATIONS Paga Fi Tirm ditch No. 1 U .rm ditch No. 2 11 3. iiirm ditch No. 3 12 4. Adjustable " V " M<Tai>er or crowder 12 5. Farm .lit<-h \... 1 12 6. Farm ditvh N... 4 12 7. rami >litcl> No, r> 13 H. Funii aitrh Nu. 5 , 13 9. lloiiit'lllildf level 16 10. Lutenil »le:id gate 17 11. PlanM I if ueir box 18 12. division IM>X in lat«-ral 18 13. (frader 21 1 I I'"li)o<ling from tiel<l laterals 21 1'). I'looding from ditchcH running down steepest slope 22 16. l.«th pipe for dit. h l..iiik 23 17. Pi I >•• for ditch haul, ma Ic ;r .in half-iucli hoards 23 is. Woo-leli (hlMle 23 19. ('ro.-M .scctitiu of S-in<h cement tiume 24 20. Low and broad check levee 25 21. Constructing lateral ditrli with scraper 25 22. (iato in check lev. e 26 23. Plan of irrigatetl ganleii 29 24. ('anvas tlam 30 'J'>. Metal dam 30 • 'MH (4) PRACTICAL INFORMATION FOR BEGINNERS IN IRRIGATION. INTRODUCTION. There are several million acres open for settlement in the United States under irrigation works built by private enterprise, and works are being constructed by the National Government to provide a water supply for more than a million acres of arid lands. So large an area of fertile land provided with a water supply and the widespread inter­ est manifested in irrigation are certain to cause an influx of settlers into western America during the next few years. These settlers are likely to come from humid regions, where many of the methods used in irrigated farming are neither practiced nor understood, and unless an opportunity is given this class to become familiar with proper methods their efforts may result in failure. The purpose of this bul­ letin is to give such information as will best serve the interests of these new settlers. The chief difficulty encxjuntered in its preparation was to make it both accurate and applicable to a large number of localities. On account of the limited space, the extent of territory included, and the wide diversity in the soils, crops, and climate of the arid regions, it was found impossible to give as much detailed descrip­ tion as would otherwise seem desirable. The first few pages of the bulletin contain some suggestions to those who are confronted with the task of selecting a farm under an irriga­ tion system. Arid soils and water supplies are considered in a gen­ eral way from the standpoint of the irrigator. The greater part of the paper is taken up with a somewhat fuller description of how to locate and build farm ditches, how to prepare land to receive water, how to irrigate a few of the staple crops, and how much water to apply. SELECTION AND LOCATION OF AN lEEIOATED FABM. Climate and crops.—The intending settler, in decidingwhere to locate, will be guided to some extent b}-^ the climate and the crops which can be profitably grown. Those who prefer a mild winter climate will be juitu- rally attracted to the southern belt of the arid States, which includes 263 (5) 6 Texas, New Mexico, Arizona, and tlie greater part of California. Those who pref«»r cooler summers, coupled with short winters of frost and snow, will tiud a location suited to their tastes in the central belt, extending from westtirn Kansas through Colorado, Utah, Nevada, and north on the Pacifii^ slope to eastern Oregon and Washington. Those who come from uorthtMn hititudes will do well to consider Nebraska, the Dakotas, Wyoming, Idaho, and Montana. The soil and climatic conditions will detorn)ine to a large extent the crops to be grown. Character and depth of soil.—In choosing land which is to be irrigated a careful examination should be made of the character and depth of the soil, its behavior when irrigated, the slope and evenness of the surface, the presence of injurious salts, and the facilities for drainage. One of the best indications of the character of the soil is the native vegetation which grows on it. When sag(d»rush, bulbilo grass, or cactus is fdiuid <iii 11 triu't, it is reasoniiMy crrtuin that the soil is fertile, easily tilled, and well drained. The ])lunts named are hut a few out of a large group which grow on good soil, easily irrigated. On the other hand', the presence of greasowood, saltwort, salt weeds, or other similar plants is indicative of a heavier soil, less easily cultivated, and contain­ ing more or less of the injurious salts usually grouped under the eoiiiinoii imnn' of alkali. In arid regions cultivated plants are deep rooted. They draw their supply of plant food and moisture from consideral)le depths, and the deeper the soil the larj:;*'!' is the feeding o-roimd for the roots and the greater is the capacity to store water. In the warmer parts of the West the top layer of soil is used chietly as a sort of blanket to protect the nloi-^t soil ))riii'alh, w hirh furnishes hoth food and water to the fibrous roots. Th(> presence of any hard, impervious stratum lying between the first and fifth foot prevents deep rooting and the storage of mois­ ture. .V hard •stratum lying between the fifth and tenth foot is like­ wise injurious, hut to a less extent. On the other hand, a porous stmtum of coarse gravel may waste largo quantities of irrigation water by penuitliiio' ii to percolate beyond the root zone. It, howevi^r, insures good drainage, and is more desirable than an impervious sub- s(.il. The character of the subsoil may bo readily determined by bor- iiio- holes with a suitable soil auger to a depth of 10 feet, if necessary, and ttikiiig sampU's of soil at different depths. Absorption of water by the soil.—Easily irrigated soil will absorb sutlii ieiit water in twenty four hours after an irrigation to become moist to a th'pth of J or '•> fin^t. Some soils are so impervious that it is difficult to wet nu)re than a few inches below the surface and others are .so pt)roiis that the water soon percolates through them beyond the reach of the dt^^pest roots. The surface of other soils bakes and cracks after each wetting, which renders cultivation ditticult. It will usually he possible fo find similar soils under irrigation in near-by ::o3 7 fields, but if this is not possible, a trial may be made on a small scale to determine how the soil acts under irrigation. In general, sandy loams irrigate well, while clay is hard to cultivate when wet, does not absorb water readily, and bakes and cracks when drying. Surface conditions.—^The intending purchaser should likewise exam­ ine with much care the nature of the ground surface. The best con­ ditions are a smooth surface, with a uniform slope of 10 to 20 feet to the mile. Such land costs little to put in shape for the spreading of water over it, and the slope insures good drainage. At the other extreme, one finds land full of buflfalo or hog wallows. These alter­ nating heights and hollows are difficult to reduce to an even gnide. Again, the land may be cut up by ravines, thereby increasing the labor and cost of putting water upon it, or it may have too much or too little slope.