Annual report of the Department of Irrigation, fiscal year 1926-27
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Study of underground water in the Las Vegas Valley and the drainage of irrigated land in the Moapa Valley. F. L. Bixby was Senior Irrigation Engineer of the Irrigation Division of the Government Bureau of Public Roads.
ANNUAL REPORT OF THE DEPARTMENT OF IRRIGATION FOR THE FISCAL YEAR 1926-37. Project #29, Purnell, at Las Vegas, Nevada. Based on cooperative agreement between the Nevada Agricultural Experiment Station and the Irrigation Division of the United States Bureau of Public Roads. by F. L. Bixby, Senior Irrigation Engineer, Project Leader, and W. L. Stockwell, Jr. Junior Irrigation Engineer for the Irrigation Division, and George Hardman, Assistant Research Prof. of Irrig. for the Experiment Station. The three major studies now being carried out under the above agreement together with their various subtopics are as follows: 1. Development of Underground Waters. a. The measurement of the wells and springs of the Las Vegas Valley add correlation studies of the precipitation on the surrounding mountains. b. The determination of the capacities of non-flowing and small flow artesian wells of southern Nevada by pumping. c. Development of springs. 3. Drainage of Irrigated Lands. a. Drainage investigations in the Moapa Valley. b. Mapping and classifying of lands in the Moapa Valley to determine feasibility of proposed flood control and water storage project. 3. Soil Fertility and Crop Adaptation. a. Fertilizer experiments with soil in pots. b. Cooperative Field Fertilizer Trials. c. Experimental Farm. Measuring Airways Well spring - 1927. flow - 1.72 cfs. Union Pacific Well summer - 1927. flow - 3.67 cfs. For the purpose of this report the engineering features of the work will be discussed under two general heads, namely: 1. Development of Underground Waters. a. The measurement of the wells and springs of the Las Vegas Valley and correlation studies of the precipitation on the surrounding mountains. b. The determination of the capacities of non-flowing and small flow artesian wells of southern Nevada by pumping. c. Development of springs. 3. Drainage of Irrigated Lands. a. Drainage investigations in the Moapa Valley. b. Mapping and classifying of lands in the Moapa Valley to determine feasibility of proposed flood control and water storage project. 1. The Development of Underground Waters. a. The measurement of artesian wells. There are several new wells in the Las Vegas Valley which are reported this year bringing the number measured to 55. There are possibly 150 to 175 wells in the Valley but the wells measured are those that are easily accessible and are considered as preventative of this artesian belt. For convenience the wells and springs have been grouped in four divisions, the first three being in the Las Vegas ^ / \ F L 0 '.V N .VINTE3 FLO'.YS GROUP I R3PR2S-1NT\TIV-: V^LLS 1326 TA'LOR LINDSAY SUND 1927 SULIi.^R ElOVS J ___j_ 192.^ 1924 1925 LEGEND SXOXE EG2HN1T0N SYNDICATE I SYNDICATE 3 Groupl Rt?presen1*jr<ve Wefts 1922 !923 ]923 t<?24- (9 24-)92J (925 !<?26 !f26 !<H7 Summer Wnfer Sunnnetl^tntcr Summer^nterSumm^r Wtnt'er^M^'neyWifnfer Summer Legend (5mohe 2 Eyttn^ton 3 Syndic, ate ! 5 5/n drcate 3 8 ho/)or ^ Lindsay i! Sund Valley and the fourth the wells and springs of the Pahrump Valley. I. The upper Mesa Group. II. The wells in and about Las Vegas. III. The wells in the southern end of the Las Vegas Valley, IV. The Wells and springs of the Pahrump Valley. Name 1 Smoke 2 Eglington 3 Syndicate 1 4 Syndicate 2 5 Syndicate 3 6 Syndicate 4 7 Syndicate 5 8 Taylor 9 Lindsay 10 Sund 11 U. P. 12 Jefferson 13 Tule Springs 14 Wickmans 15 Air Ways 1 Smoke 3 Eglington 3 Syndicate 1 4 Syndicate 2 5 Syndicate 3 6 Syndicate 4 7 Syndicate 5 8 Taylor 9 Lindsay 10 Sund 11 U. P. 12 Jefferson 13 Tule Springs 14 Wickmans 15 Air Nays Group 1. Wells of the Upper Mesa area. Summer Measurement in C. F. S. Year The wells of the upper Mesa Group as a whole have shown a decrease which may be attributed to a light rainfall in the Spring Mountains, and to the further fact that wells 14 and 15 were drilled and brought in with good flows. Although these two new wells do not seem to affect one another they have a considerable affect on other wells in the vicinity. The Wickman well when open reduces the flow of the Eglington and the Smoke Wells to a point where the water does rise over the top of the casing and the flow of syndicate numbers 1, 2, and 3 drop from 0.74cfs to 0.60cfs for no. 1, 0.94 to 0.78cfs for no. 2 and 1.08 to 0.84cfs for no.3. The air field well does not seem to have as quite as great an affect on the series but has reduced the flow of some wells south and east of it. Among these wells are the Jefferson well and the old Boul wells where the water surface drops to 3 feet below the top of the casing when this well is opened to its full capacity. The measurements on the Union Pacific well show that it has fallen off in flow to some extent. The most recent reading show that this well has a flow at this time of 3.95cfs against a flow of 5.86cfa. in March of 1925. This well's decrease may be due to sanding up and fact that the joints in the casing have become closed cutting off the flows of the upper strata that might have been seeping in before. Group 11 Wells in and about the Town of Las Vegas Summer Flows in C. F. S. Name Russell Dinsmore Tate Filbey Ullom Haggard Anderson Brown Dutton Sypdioate 7 Syndicate 8 Parkd Oppedyke Hunt Winter Flows in C. F. S. Name Russell Dinsmore Tate Filbey Ullom Haggard Anderson Brown Dutton Syndicate 7 Syndicate 8 Parks Oppedyke Hunt Croup LI Represented vVeN 1923 ^1924 1925 LEGEND UPSHIFTS ?ASNO lA'IKOrl ILA-'T) The wells in this group in many cases have shown decided decreases but in the main these are evidently nothing more than the usual seasonal variations. A number of new wells have been drilled in this territory but they have mostly tried for the deep water strata. Two of these wells are noted here for the reason that they were drilled along the lower edge of the artesian belt, and encountered two different formations and neither well found a great deal of water below the six hundred foot level. The Hunt well is now the deepest well in the Valley being 1150 feet deep and having a flow of 0.50cfs. Of this about 0.50 is from the upper flows of 300 and 600 feet, the rest from below the 600 feet depth. The formations in this well were alternate strata of limerock conglomerate and clay, which is the general strata-fication found in nearly all of the wells in this vicinity. The Parhieme well was drilled earlier in the year and was put down to a depth of 950 feet. This well, after the first 300 feet, was in clay formation all the way down, the water being found in narrow veins of sand in the clay. This formation is not often found in the Valley and would seem to indicate that there may be a clay dike on the eastern edge of the Valley which is holding up the water and giving the Valley its artesian flows. The walls of the third group are located in the southern end of the Valley. Although in general it is a stable group some of these wells have shown a tendency to fall off in flow this year to a considerable extent. One new well was drilled in this section in the last year and the formation encountered was so entirely different that it in mentioned and a log of the yell given. It will noted that this well struck basalt at a very shallow depth. In other places in the Valley this formation is found below 1000 feet. This well was drilled within a thousand feet of the McGriff well and near two wells that flow about 0.20 cfs apiece. The water in this well rose to within 18 feet, of the top of the hole but never flowed. The elevation is about 30 feet higher than the McGriff well. Log of Hunt-McGriff Well No. 1 0-40 Clay 40-340 Lime conglomerate 340-351 Red Clay and boulders water rose to 100 ft. 351-685 Basalt 685-690 Gravel, Water 18 ft. below ton of casing 690-715 Basalt 715-717 Water very brackish This last stratum was stopped off by filling in to a depth of 700 ft. The following graphs show in general the variations in the flow of the artesian yells in the Las Vegas Valley since 1922. Some measurements are given here of the wells and springs in the Pahrump Valley which lies on the western side of the Spring Mountain Range and receives the drainage from that side of the mountains. The artesian belt in this territory is not as well de-veloped as the Las Vegas Valley due to the sparsely settled condition of the Valley and the great distance from the Railroad. Group 4 Wells Measured in the Pahrump Valley. In 1937 Of these the Annse, Intermittent and Williams Springs are located in the Charleston Mountains and are fed from the melting snows and local showers on the slopes immediately above them. They have an intermittent discharge varying from a maximum in April and May to a minimum in late summer. The three mile and six mile springs are near the north edge of the Valley and apparently associated with the spur of the Charleston Mountains which here forms the north boundary of the Valley. The others are in the main artesian district. Tests on Logs of Water in Open Ditches. Three interesting tests were made in the loss of water in open ditches in different parts of this territory. The first one was made on the Gilcrease ditch 13 miles north west of Las Vegas. The measurements were made in July and August of 1926 to determine the losses that might be expected in a ditch that was run through a fairly loose soil. This ditch is one and three fourths miles long, with weirs set 9000 feet apart. The total fall in the length of the ditch between the weirs was 45 feet or the grade of the ditch was on half of one percent. The measurements on the ditch are as follows: Tests of Loss of Head in Gilcrease Ditch. This ditch showed an average loss of 0.33 cfs. over the period of the measurements or about one third of the total flow. At the time of the measurement the ditch had been in operation for a period of two years. Such leaks as gopher holes and breaks in the ditch were watched for and repaired as soon as found. The next test was carried on a ditch at the Pahrump Ranch in the Pahrump Valley. This ditch was 4363 feet between the weirs, with a fall of 22 feet. Readings on the ditch are as follows: 1 Tests of Loss of Head in Pahrump Ranch Ditch. Date Upper Weir Lower Weir Difference 3/13/27 OPS. OPS. 3FS 3.60 3.12 0.48 3/16/27 2.53 2.03 0.51 3/30/27 2.59 2.06 0.53 3/34/37 2.53 2.06 0.53 3/^8/37 2.59 3.06 0.53 4/3/27 3.59 2.09 0.50 4/6/27 3.53 2.10 0.49 4/8/37 3.59 2.09 0.50 The water in thi3 litch w e ueed for running a Pelton Wheel for ice machine and furth r measurements coull not be made as it was shut off. The avera e loss of 0.51 cfs constitutes about a fifth of the flow and considering that this test waa run in the coolest part of the year when there ?as very little loss due to evaporation and transpiration it aeeaa high. The ditch itself has been used for a number of years and runs' through a very heavy clay soil that was apparently nearly impervious to water and did not cut a ?reat deal. The testa on the third dit;h are still in progress, the measurements ^iven b low beinr taken during the month of June. The ditch^ a new one uaed to brin* water from a well of the upper mesa 'roup to the Taylor Ranch,is 15,492 feet in length with a fall of 102 feet in thie distance. Teat ; Loas of Head in Taylor Ranch Hitch. Date Upper Weir Lower Weir Difference 3PS CPS CPS 6/8/27 1.69 0.50 1.19 6/11/27 1.66 0.55 1.11 6/15/37 1.36 0.60 1.06 6/30/37 1.39 0.65 1.04 6/24/17 1.69 0.65 1.04 3/38/37 1.36 0.67 0.99 3/1/27 1.63 0.67 0.99 These Measurements would indicate that it is not practicable to car^y crater over such a long stretch of country in an open ditch as the lenses ar^ too Trent. The rump te?tn in this Valley have be^n nearly completed. The tests have a'nwn that the ortural flo-y if =iany of the<?e trails may be increased to some extent and that pumping will produce considerable vater if it has to be reported to. The fir^t *11 pumped t^ii yo r *as the Beckley Backl*y *ell fl. Vila yell had a flow of Well ?1 0.019cfs. at the start of t^e te^t. numped tith the Kimball deep well turbind. The te"t in aa Pump Te^t of Beckley Well PI. Data Draw d^sn R. P. V. Weir Reading 3?3. 7/38/S 61 1013 V. H. 0.335 0.204 45 750 * 0.305 0.131 30 810 * 0.333 0.093 15 330 * 0.13 0.038 The flow at the and of the te^t was 0.028 so a slicrht increase was afforded by ircpinr;* However the small am unt of water eveloped by pumping would not justify the expense) of imtalling an outfit. The ST3.il -ells in this particular section of the country do not see? to develop any re^t amount of *ater by pumpiag.---— Hunt- This was a shallow surface well and was pumped McGriff ^ ^ to determine whether the surface 3trata in this Nell section would produce sufficient water for domestic use. The deep well Kimball Turbine was use! in this test. Pump Test of Hunt-McGriff Hell % 3. The water surface in this well stood at 32 feet below the surface of the ground and the pump test was run for eight hours at 10 feet to determine whether the inflow to the well would be affected by continued pumping. This well was dug on the extreme south end of the Hunt- Valley on the edge of the Las Vegas Wash and was McGriff Well #1 intended to be used as a supply for developing clay deposits—and for making cement brick. The well is interesting in that the log of it shows an entirely different formation from any other well in the Valley. This formation outcrops in the lover foothills of the southern part of the Spring Mountain Range. The water level stood at 14 ft. below surface when drilling was stopped at 715 ft. in a very hard lime stratum. The well was pumped with an airlift outfit, the compressor supplying 9O cu. ft. of air a minute, with a submersion of 85ft. The well pumped 0.042 cfs at this depth and held up to this for four hours. This test was made on the 25 August 1926. Pump Test of Hunt Well # 1. Date Draw down Quantity Length of Run feet CFS hours 8/26/26 85 0.042 4 Beckley Well #2 Pump Test of Beckley Well # 2 The flow at the end of the test was 0.126 cfs showing no improvement from pumping. This was expected since very little sand was pumped. This well is located in the south eastern part of the Las Vegas Valley. It is east of the Las Vegas Wash and a little out of the artesian belt. No flows were encountered though water of good quality was struck at 140 ft. that rose to about 18 ft. from the surface. Several cavities or heavy veins were found at from 300 to 370 ft. These water veins were more like underground lakes than anything, the drill dropping 20 ft. at a time with no resistance. The water immediately arose to within 33 ft. of the surface and gave evidence of a sufficient supply to insure a pumping well. A test wss made in the latter part of September with the following results. Pumping the Taugher Well yield - 1.50 cfs, at 15 foot drawdown. This well proved to be one of the strongest pumping wells in the Valley but the water is so alkaline as to be almost unfit for use. A log of the wels is given the appended log tables. Valley and some results were obtained which were quite gratifying. The wells in this Valley are thought to obtain their supply of water from the eastern slopes of the Spring Mountain Range. They are somewhat higher in elevation than these in the Las Vegas Valley, the elevation of the Las Vegas water bearing area being from 1900 to 3300 ft above sea level while the Pahrump area lies between the 2600 and 2900 ft. levels. The wells in this Valley are used for irrigation and stock watering. There are only about 3500 acres under cultivation in the artesian belt in this area. Buol This well was first tested with the Kimball Well #1 deep well turbine and then shot with 30 pounds of 80% dynamite. The results of the tent are given in the following table. Pump Test of Buol Well #1. Date Drawdown in ft. Quantity in 0. F.S. Remarks 00 0.025 natural flow at start after 24 hrs. pumping flow at end of pumping flow after shooting. 66 0.115 00 0.05 00 0.20 Pumping this well for 24 hrs. at 66 feet increased the natural flow, while the use of a small amount of powder in the bottom of the hole caused a further increase. The well is in a hard limestone formation, the water appearing in small openings in the rock. Shooting evidently has a tendency to open the water courses with a resultant increase in flow. Buol Well This well was first tested by pumping, then shot #3 and retested, and finally given a second shot. No pumping test was made after the second shooting. The results of the test are shown in the following table. Pump Test of Buol Wall #3 Pumping alone in this case causes the natural flow to increase about 100%, while shooting and pumping combined gave an increase in the flow of over 200%. The first charge of dynamite doubled the yield of the well under pumping, and it may be assumed that a further increase would have resulted from the shooting had the test been carried out. Buol A single run of 24 hours was made on this well. Well #3 The yield under the pump and the flow after the test are shown. r ^ Mc Donald Well, looking toward Mt. Charleston. Freak Wells-in Pahrump Valley, same depth, same size casing, eight feet apart. Raycraft Wells #2 and #3. f--7 Pump Test of Buol Well # 3. While the yield of this well at the drawdown limit of the pump was too small for economical pumping the increase in the natural flow after the test was sufficient to warrant the expense of such a test. McDonald This well is also located on the valley floor Well but is about 3 miles nearer the foot of the moun- tain slopes than the Stennett well. The water level in the well stood 18 feet below the ground surface at the time of the test. A single run of 8 hours with the Kimball pump was made, the discharge during this time at a drawdown of 66 feet averaging about 0.16 cfs. The yield was not considered sufficient to justify further testing. There appears to be considerable water under the central portion of the valley, but the artesian pressure is not sufficient to bring it to the surface and since it la found in thin layers of fine sand that does not yield the water readily the opportunity for successful pumping wells does not appear favorable. These three wells are located on the northern edge of the artesian belt and appear to be affected to a greater extent seasonal variations in the water supply than other wells in the basin. The owner reports a decrease in flow since other wells in the vicinity have been drilled. It appears from the results of the above tests that either pumping occasionally or shooting with heavy charges of a high percentage dynamite might pay in increased artesian flows. Which would be the more economical method would depend upon the facil-lties available, dynamite probably being cheaper at the present time. This well is situated about 6 miles east of Stennentt the Buol series on a clay flat near the center well of the Valley. Although the well is over 600 feet it was never a flowing well, the water standing 16 feet from the surface of the ground at the time of the test. The same is true of several other wells in, this immediate vicinity. Since the well is cased with 6 inch casing the Kimball pump could not be used. A 2-inch horizontal centrifugal, installed in a 10 feet pit, was made use of in this test. The discharge after a six hour run at a drawdown of about 23 feet below the bottom of the pit was 24 gallons per minute. Pahrump This well was drilled in 1912 and is on the Well # 5 southern edge of the Pahrump Ranch, a mile south east of the big Pahrump spring that as the original water supply of the Ranch. This well had been pumped with a centrifugal pump since years previous to the test. The well flowed 0.64 cfs at the start of the test with quite a heavy pressure head. This test was made with the 6-inch Kimball deep well turbine with results_as shown in the following table. Pahrump Well #5 flow - 0.64 cfs, lump Test of above Well. Yield at 47 feet, 2.23 cfs. IRRIGATION Water Application The length of time necessary for the water to be on the land to permit the desired depth of penetration should determine the size of head and the width and length of the checks. The factors which affect penetration are slope, texture, and subsoil conditions. The table below presents the recommended width and length of borders for light, medium, and heavy soils for heads of water from one to five second-feet. The time required to apply specified depth of water is also given. Head of Wa - (1) Light Soils OLA (2) Medium Soils 0MA (2) Heavy Soils 0HA ter for ea. 0LB 0MB OP [B Border Width Length Area Time Width Length Area Time Width Length Area Time (3) c.f.s. Ft. Ft. Acres Min. Ft. Ft. Acres Min. Ft. Ft. Acrea Min 1 15 220 .076 18 20 330 .152 54 30 660 .455 163 2 20 330 .152 18 30 440 .300 54 3 30 440 .30 24 30 550 .376 45 4 30 440 .30 18 5 30 440 .30 15 (1) Approximate time for 4" application (2) Approximate time for 6" application (3) c.f.s. (second foot) equals 40 miners inches A. R/'d.'Hca. t^^ey C fT Va.//ey C. /V. ^yjer /VeaJow V that in apparently all the available water has been developed. This ranch is one of the oldest in the Las Vegas Valley, being first occupied about 1850. The particular inducement here was an area of good soil watered by a series of springs. These springs had a flow estimated at about 12 to 15 miners inches (40 inches per sec. ft.). Little or no effort to increase the flow of the springs was made for many years. Recently a reservoir capable of holding the overnight flow was built, which permitted a larger irrigating head for a shorter time. A small well was drilled some distance back of the springs on higher land and piped to the house for domestic use. This is well # 1 in the accompanying sketch. In 1924 the ranch wan sold to Mr. Taylor who immediately began the development which ended this summer. The first effort was a well about 1/2 mile west of the springs and at an elevation nearly 50ft. higher. The flow obtained was small. It was ditched into the reservoir and becomes part of all subsequent measurements of the total flow of the springs. During the summer of 1925 two wells were drilled. These are about 150 feet from the edge of the reservoir and about 26 ft. higher than the level of the water in the reservoir. Neither of the wells gave a strong flow but responded fairly generously when pumped. Syphons leading into the reservoir were installed the following year on these wells and gave a fair increase over the natural flow. Previous to the drilling of the wells discussed above some development work had been carried out on two of the springs. Of these # 3 on the sketch was a small seep into which a trench was cut and a drain installed. A flow of about 2 inches was developed here, which was not led into the reservoir. No 1 spring had been tested by our department a number of years ago by pumping but had since been neglected and the flow obtained at that time largely lost. The present work consisted of running a trench into the spring at a depth of about 10 ft. sinking a wooden casing in the spring to keep the sand and muck out, and laying a pipe line in the trench from the spring to the reservoir. The flow increased following this development from about 2 inches to about 12 inches. Drilling with hand rig in old spring at Taylor Ranch. Pumping-Taylor Well #4 yield 1.90 cfs, at 23 feet drawdown. At the beginning of the year 1927 the following wells and springs were discharging into the reservoir; wells numbers 2 and 3 and springs number 1 and 2 and several small seepages. The total flow as shown in the following table was 0.83 cfs. In addition well #3, supplying the house and spring # 3 were flowing. Well #4 was then drilled on the upper bank of the reservoir as near the water as possible to set the drilling rig. This well came in with a flow of about 0.69 cfs. However, the total flow from the reservoir measured only about 1.04 cubic feet per second, thus showing a gain of 0.21 cfs. only, and indicating clearly that this well was obtaining its supply from water that would otherwise largely have appeared in the previously developed wells and springs. The old spring in the center of the reservoir, # 2, suffered the most severe loss, the spring # 3 and well # 2 showed a reduction in flow. Since these are both north of the new well and on somewhat higher land the conclusion drawn was that the water flow was coming from the southwest and that the new well with its lower outlet was intercepting the flow. The spring in the reservoir which was once the chief source of supply had now practically ceased to flow. In an effort to restore this flow the driller put down a line of three inch casing directly into the center of the old spring. Many reports of the depth of these mound springe, varying from several hundred feet to bottomless pits, have been received, but in this case the quicksands were penetrated at 30 feet. At this point a stiff clay was encountered and from there down it was necessary to use a jet pump and hand spudding rig. The casing was sunk to about 40 ft. before the spring flow returned, and then to the extent of only a few inches. It was believed at this time that the limit of the water supply had been reached at this place, but to further test this assumption a pump test was installed and operated at full drawdown capacity of about 23 feet for hours. The discharge of the pump at the beginning of the tent was 1.90 second feet dropping to 1.38 second feet at the end of the tent. The interesting part of the experiment, however, was the behavior of the other wells and springs during the test. Spring # 2 in the reservoir stopped flowing immediately. After about 13 hours pumping spring # 3 was dry and the syphon on well # 3 broke. At the end of 24 hours pumping the water dropped sufficiently in well #3 to break the syphon, and spring # 1 decreased about half, but did not cease flowing at any time during the test. Before the end of the test well # 1 leading to the house ceased flowing. Some time elapsed after the pump was stopped before the total flow returned to the normal. The story of the entire development and pump test is told in the following table. Table showing Discharge of the Taylor Springs at Various Stages of Development. Table of Results of Final Pump Test at Taylor Ranch. Before ending the test practically all the water from the whole series of springs and wells was coming thru the pump on # 4 well. The flow in spring # 1 has returned somewhat, but spring # 3 remains dry. The house well, # 1, has regained a part of its flow, but neither of the syphons has yielded enough to keep them primed and they both have been abandoned. The Muddy River occupies the lower extremity of The Muddy a rather large drainage basin, through which River at an earlier date the ancient White River flowed. Springe The principal topographic features of the valley, such as the flood plains or present valley floors, the deep, narrow, steep walled canyons and high excarpments that border the valleys are all the work of this old river. Except for a very brief period following exceptionally heavy storms the bed of the old White River is dry for the greater part of its length, the only surface floor occurring where springs appear. The most important of these spring systems are those in the White River Valley, the Pahranagat Valley and the Moapa Valley. The springs that feed the Muddy River issue from limestone and conglomerate at the foot of a low limestone hill. Other seepages occur in the bed of the river. The flows from the larger springs readily find their way to the main stream but many of the smaller springs and seepages fail to reach the stream, the water being lost through evaporation and transpiration. There is also an area of land adjacent to the springs that is somewhat swampy and from which some water appears to be lost by evaporation. The total flow of the Muddy River, with a drainage area of 1080 square miles, as measured over a weir a short distance below the springs is about 50 second feet, varying rather widely with the seasons and somewhat from year to year. The rainfall over much of the drainage basin is very light and the runoff practically nil. There are, however, several mountains ranges upon which the precipitation is sufficient to permit some runoff and it is from these mountains that the bulk of the supply for the Muddy River Springs comes. It is not believed that a large supply of water is escaping underground and that this water can be brought to the surface to increase the flow of these springs but rather that the very small flows may be consolidated and the seepages cut off and in this manner all the water conserved. The present development was carried out on a group of springs known as the Bloedel Springs. These springs issue from the foot of a slope at an elevation of 10 to 15 feet above the valley floor. The work consisted of starting at the lowest feasible point and trenching toward the source of water. The first work in the development was the drilling of 3 series of holes along the slope of the hill about 50 feet back of the springs. These holes were about 10 feet deep and 5 feet apart, and the holes in each series staggered so as to cover as much of the territory as possible. The rise of the water surface in the holes directly back of the springs showed the fastest rise. The channels were then dug toward the holes showing the greatest rise. The accompanying sketch illustrates the position of the various springs on which work has done together with the weirs used in measuring the flow increases. The springs are numbered while the corresponding weirs are lettered. Measurements were made of the flow from each individual spring and of the total discharge of the group before any development was started. The flows of the various springs and the group are shown in the following table. Diacharge of Bloedel Springs before Development. The measurement marked # 12 over weir 1 was made in the ditch leading from the springs. This total also includes a small stream from another series of springs, but this doss not affect the final results since this stream is included in all the measurements of the total flow. Springs numbers 1, 3 and 3 were not worked on because of the fact that they had strong flows nd showed evidence of having been developed at some previous time. Springs 4, 5, 8 and 7 were trenched back first, but when the trench of number 6 reached the level of numbers 4 and 5 these ceased to flow, indicating that these were merely seepages of the surface gate^ filled tna ground above the outlets of numbei 8 and 7. The flows in number 6 and 7 inore^s^d materially and finally when a le^ge of rock was reaohed at a deoth of 10 feet from the surface and 50 feet back from the starting point a crevice was found which Aas opened and the work on these two -topped. The inci asea obtained on these two Borings are K own in the following table. Development of Bloedal Springs # 8 and % 7. Bate Spring 0. 8. Rem rka No. 5/28/37 6 0.085 Original flow 7 0.080 * * 8/14/37 3 0.33 Ledge of rook reached. 7 0.21 * ' " 6/18/27 6 0.73 Ledge of rock broken. 7 0.438 * * * " 6/30/37 6 0.72 Last measurement. 7 0.428 * " Springs jSand 9 were next orked on. These were started at the bottom of an old talus slope and carried back by trenohing to a vertical ledge of limestone from under which the water seemed to be coming. A section was broken out of thia wall *nd a conaider-able increase in flow obtained. The table given below shows the increaaea obtained by development of theae springs. Development of Bloedel Springs # 8 and # 9. Date Spring No 0. F. S. Remarks 5/38/27 8 & 9 0.125 First Reading 8/30/37 8 & 9 0.503 Lime reef appeared 8/31/37 8 & 9 0.745 Lime reef broken 6/33/J7 3 & 9 1.40 Trench completed 8/30/37 3 & 9 1.44 Last reading. Spring number 10 next developed by trenching. Thia t? nch 3ras dry except for a small flot? in the bottom of the ditoh until a ledge of rook pas reached. The trench iras deepened along t^e f^oe of this ledge until a crevice was found at a depth of 9 feet from the ground surface and 5? feet froi the ctartinp point. Thia crevice was enlarged by drilling nn' brc3l<ing cut r. 3mall piece of rock. The table belO'<" givoR the ntory of the development oftthis npring. Development of Bloeoel Spring ^ 10. Date C. ?. 8. Remarks 5/39/37 0.0^3 ^ir?t reading 8/38/37 0.336 Lime ledge reached 8/^7/17 0.934 time ledr-e broken 3/10/37 tant reading. Tha 1 :t re d a^? of the year were made on June 30th .'.ith the results as shown in the follo-siat? table. Disch^r ! f Bloedel Springs following Development. Pate Spring No. Weir Reading 0. F. S 3/30/37 No. Type 1 A V. M 0.39 0.340 3 & 3 B ' rcct 0.43 1.7H 4 & 5 C V. N. 0.00 0.000 P i 1' rect 0.77 0.717 7 E 1'. rect 0.25 0.404 8 & 9 F 1 rect 0.45 1.44* 10 0 rect 0.44 0.934 1^-11 H reot 0.33 13 1 3' reot 0.78 8.33 The total increase obtained from cleaning out these three springe was from 3.32 cfs the total flow of all the springs at the start of the work to 8.33 cfs at the completion of the development. This gain of 3.01 cfs will undoubtedly fall a little as the water bearing area works off the excess head. In order to determine the permanency of the present development it will be necessary to continue the measurements of the flows for at least another year. During this time the trenches will have to be kept free from all debris and in approximately the condition they were when development stopped. The possibility of future extensive development of the whole group of the Muddy River Springe depends at least in some measure upon the records of the present development, hence it is particularly important that accurate records should be obtained over as long a period as possible. The Muddy Valley Irrigation Company and others interested in the flow of the Muddy River may agree to continue this work after a year complete record of the present development and the flow of the Muddy River has been obtained. To this end a new weir crest and water stage recorder were installed on the 12 foot Home Ranch weir at the head of the Muddy River. This weir is below all the inflows to the Muddy River except the Meadow Vallay Wash. The water master for the Muddy River will attend the instrument and change the record sheets weekly when he makes hia rounds of the upper river territory. An increase of 3 second feet in the flow of this river during the hot part of the season might mean one of two things to this vallay: the addition of about 200 acres of land to the productive area of the valley with a sufficient amount of water to grow crops, or the shortening of the period between water turns considerably during the season of greatest use. There is undoubtedly more water to be developed in this area by the cleaning out of the other springs that feed the Muddy River, or by the drilling of a number of wells in this area to intercept the flows of these springs. The present development by our department may lead to more extensive efforts at a later date. 3. Flood Control and Drainage. The drainage work this year has a. Drainage Investigations in the Moapa Valley. been that of collecting data on the depth of the water table over the Muddy Valley. This information may than be used by the Muddy Valley Irrigation Company in determining the means to take in ridding these lands of alkali and in lowering the water table of the valley to a poiht where it will not be injurious to crop productions. The work included the sinking of a number of additional wells in the valley in areas that showed a high water table, and the reading of all the wells by a resident of the valley about three times a month. There are now 64 wells in this area, spaced about one half mile apart and usually located near roads or fence lines for easy accessibility for observations. The avarage depth of the water table over this area seems to be about 4 feet below the surface during the summer and shows a rise for nearly 3 feet during the winter months when the lands are not in use. The area covered by the wells should be extended to include lands farther up the valley which do not at this time show many indications of waterlogging but which may be affected in the near future, b. The Mapping and The field work of mapping the Moapa Classifying of lands Valley lands to assist in the determina-in the Moapa Valley. tion of the cost which these lands might stand under the proposed irrigation district plan was well under way by the first of July. The lands to be included in this survey are the lands in the valley already under ditch and those not under ditch that might be brought under cultivation if additional water could be obtained. The information desired includes the total area of land now under ditch, the acreage of tilled and tillable land, the acreage of land actually cultivated and the acreage of waste land in the area. Similar data on the land proposed to irrigate under the enlarged canal system is likewise desired. The area of land needing drainage should be determined and mapped. The above information when used in connection with the economic survey recently completed by Mr. Headley of the Experiment Station, the soil survey of the Moapa Valley by the Bureau of Soils and additional studies of the producing power of the various soils which are to be made soon, and the detailed surveys of the proposed flood control and storage reservoirs should be very valuable. Such studies are necessary in arriving at the feasibility of any project. 3. Soil Fertility and Crop Adaptation. a. Fertilizer experiments The corn crop on the pots this past with soil in pots. 1926-27. season was almost a total failure. The crop started nicely but the extreme heat /r Cannon Series sour clover ^ /i/ ^ /r Houseman Series sour clever Experiments with soils in Pots - 1927. Jefferson Series sour clover ^ ^r las Vegas Series sour clover Jeiiersoh Series sweet clover in July and August caused the crop to wither and it made practically no growth. It was very difficult to cultivate the small surface area in the pots and the soil takes on a very hard, unfavorable texture from the frequent irrigations. A winter crop of clover was seeded in September, sour clover being used again on all the pots except numbers 1 to 6 and 13 to 18 of the Jefferson series which were seeded to Hubam clover. The growth on all the pots was satisfactory, though as in previous years phosphorous was the only element living a marked stimulation. The story of the growth of the clover is told very clearly in the following series of pictures. b. Cooperative field fertilizer The cooperative field trials with fertilizers trials. 1926-27. were started in 1925 in an effort to secure some data on the effect of the various mineral fertilizer elements upon several different soils and crops in the Las Vegas and Moapa Valleys. Under this cooperation the Experiment Station furnishes the fertilizer materials and supervises their application. The farmer is expected to apply the fertilizers according to the plan furnished and keep a complete record of the growth and production of the various plats. The cooperative trials for this year are five in number, two in the Moapa Valley and one in the Las Vegas Valley. The work has been successful and the relations between the Experiment Station and the cooperators cordial. The general plan for the application of the fertilizers as worked out with the help of Dean Stewart of the College of Agriculture is given below. PLAN FOR FERTILIZER APPLICATIONS IN FIELD TRIALS. In the Las Vegas Valley two plats of peaches E. G. McGriff and one of grapes were originally selected on Orchard. the farm of Mr. E. G. McGriff. Out of the original selection one plat only of peaches is now retained. This is a plat of early Albertas, which was kept because of the marked effect of the fertilizers upon the trees and the convenient location of the plat. The applications of fertilizers have been made according to the general plan, except that the fertilized rows were not duplicated and the amount of material given each tree has been varied somewhat from year to year. In regard to the duplication of treatments it was felt that in effect each tree could be considered an individual unit and that there would be no practical benefit obtained from further duplication. The first applications of minerals was made in 1924-25 April, 1925 at the following rates, ammonium sulfate 2 pounds, acid phs8phate 2 1/2 pounds, potassium sulfate 2 pounds and the complete fertilizer 6 1/2 pounds per tree. Late frosts almost completely destroyed the fruit crop so there was mean of estimating the effect of the fertilizers upon the fruit crop. However the effect of the ammonium sulfate, both alone and in combination, upon the vegetative growth was fast and startling. Within the first two weeks after the application of the fertilizers the growth on the trees receiving this treatment was greater than the average growth of the orchard for the season, and this rate of growth continued until the new wood on these trees averaged at least four times greater than on the unfertilized trees. There was little visible effect from the use of the other two elements. The rate of application of the ammonium sulfate appeared to be a little too large, especially when used in combination with the phosphorus and potash, and caused too great a stimulation of the trees. However there was no winter killing and the trees appeared in good condition the following spring. The second application of fertilizers to the peach 1925-26 trees was made in February, 1925. It consisted of about one pound to each tree of ammonium sulfate and potassium sulfate, and one and three fourths pounds of acid phosphate, and three and three fourths pounds of the complete fertilizer. Believing the results of the test the past season sufficiently conclusive Mr. McGriff gave all the trees in the orchard, except the trees in the experimental plat, a light application of ammonium sulfate. For this reason the trees in the experiment did not stand out from the rest of the orchard as they did the past season. This year an excellent crop of peaches gave an opportunity to observe the effect of the various fertilizer elements upon the fruit crop. In this connection it was noted that the phosphorus and potash appeared to hasten ripening while the ammonium sulfate seemed to retard. It was the opinion of the owner that this latter would be a most favorable factor toward producing a good quality of fruit as it tended to allow a more natural ripening. The more abundant foliage on these trees protected the fruit from the hot sun in June and reduced the percentage of sun scald. The application of fertilizers were again made in 1926-27 February, and at about the same rates as in the proceeding season. Due to an error ammonium sulfate was applied to the check row and since all the remaining trees in the orchard received a small application of this material there is really no check left in the orchard. The two rows receiving phosphorus and potassium given such negative results the two previous seasons that Mr. McGriff figured a small amount of ammonium sulfate might do no harm and gave them all a light application of this material. The experience of this season confirms the conclusions of the two preceeding years. The set of fruit on the trees receiving the ammonium sulfate was excellent and the June drop lighter than usual. The effect of the denser foliage in protecting the fruit from the direct rays of the sun and in this manner allowing a more natural ripening was again demonstrated. The direct effect of the nitrogen may also be in this direction. According to Mr. McGriff this is a desirable tendency, the fruit from the fertilized trees having a better flavor and keeping qualities. The picking season is also extended somewhat which is a favorable effect when the fruit is consumed locally. The exact increase in the yield of fruit from the use of ammonium sulfate was not determined but from observations on the growth of the trees, the number of fruit spurs and the apparent amount of fruit per tree it is estimated that the use yield of peaches on of this material has easily doubled the this orchard. Mr. McGriff has estimated that the use of ammonium sulfate to the value of about $250 has given him an increased Asparagus, Wells Bros. spring - 1927. return in fruit to the value of about $2500. In addition to the direct return the use of this material has given new vigor to the trees and promises to greatly prolong the useful life of the orchard. It is our intention during the coming season to have Mr. McGriff discontinue the application of ammonium sulfate to the check, phosphorus nd potash rows and restore the experiment to its original basis. Some idea of the lasting effect of the application of ammonium sulfate may be gained from a study of the behavior of the trees in the check row. The field of asparagus on the farm of the Wells Wells Brothers Brothers now being used for the fertilizer work is Asparagus one of the oldest in the Moapa Valley. It has been fertilized several times in the past with barnyard manure and is now in a fair state of fertility, though at the time the experiments were started the yield had fallen somewhat from the peak production. It was selected because the soil is uniform, the stand well established and the field small enough to handle as a unit. The soil on which this experiment is being conducted is a heavy, dark loam, underlain with a dark peaty material. It is a vary good asparagus soil. The fertilizers are applied according to the general plan as given above. The initial application of fertilizers was made in 1924—25 April, 1925. The first cutting of the asparagus having been started by this time it was of course too late for any benefit to the current crop. Moreover, the harvested part of the asparagus crop depends largely upon stored up food in the roots, which in turn depends upon the previous season's growth. Hence an application of fertilizers at this season was expected to benefit the growth after the cutting season and this benefit should be reflected in increased yields the following year. Mr. Wells kept a record of the yield of each plat for comparison with the production of succeeding seasons. Observations were made on the growth of the plants at intervals during the summer, and while it is extremely difficult to rate the differences in growth of such a crop as asparagus from visual observations the growth appeared stronger and continued longer on the plats which received an application of potash or phosphorus. That is, plats 3, 4, 5, 8, 9 and 10 appeared a little better than the checks. The second application of the fertilizers to the 1925-26 asparagus was made in February, 1926, at the same rate as previously. The record of the production of each plat is shown in the table given below. Mr. Edwin Wells reports that for some unknown cause a portion of this field including plats 6 to 10 appeared to suffer from drought to a greater extent than the balance of the field though every effort was made to give each plat the same amount of water. The fertilizers were applied in February this season. 1926-27 It had bean hoped that a small fertilizer drill would be available for spreading the materials but could not be obtained so the fertilizers ware again spread by hand. The yield this season was slightly less than in the immediately preceding years. This decline may possibly have been due to the late cool spring, tho more likely to the lighter growth of the preceding summer. T&e blame for this light growth may be laid in part to the extremely hot, dry summer with its accompanying scarcity of irrigation water and in part to the attacks of rust. Asparagus rust had never been known in the Moapa Valley before this season, and in normal years the danger from thin disease is probably negligable. The summer of 1925 witnessed an unusually severe attack of rust on grains, grasses and native vegetation, and the asparagus did not entirely escape. The yield in pounds of each plat of the experimental field for the years 1925, 1926 and 1927 is shown in the table below. Table Yields - Wells Bros. Asparagus. It is not possible to draw any conclusions from the data gathered to date on this experiment. All the plats with the exceptions of numbers two and three, show decrease in yields when compared to the 1925 production. The average decrease of the three check plats la 50.1 pounds per plat as compared with the average increase of the two plats receiving nitrogen alone of 0.2 pounds and of phosphorus alone of 2.05 pounds. Potash alone gave about the same production as the check plats while the yields on the plats receiving the complete fertilizer were lower than the checks. Since the asparagus experiment on the Wells ranch Jess Whipple, is being conducted on a dark, heavy, peaty loam with Asparagus, a very light coating of river flood silt it was felt 1926-27. that another field on a lighter type of soil might be valuable. Moreover considerable attention should be paid to this crop in the Moapa Valley because it is undoubtedly destined to attain a rank of first importance in the agriculture of the valley. The location chosen for the new trial is in a field of two year old asparagus. The soil is a river flood silt underlain at a depth of about three feet with the dark peaty material common to this section of the valley. The stand of asparagus is excellent and the growth of the tops very strong. A very light cutting was taken from the field this season but the experiment was laid out too late to obtain figures on the yield from the various plats. Each plat in this field is made up of three rows, each six feet apart and 242 feet long, and contains exactly one tenth of an acre. The fertilizers were applied by hand in the furrows on each side of the center row. In this way the center rows receive double the application given the outside rows but there seems no way to avoid this and yet retain the fertilizers on the desired area when applying the materials by hand. The plan followed in making the applications was the same as the general plan given above except that two extra plats were added. These two receive manure at the rate of 20 tons per acre and are to be known as the manure checks. The plan is identical with that used on the experimental farm at Las Vegas. The first cuttings for record will be made next spring. This experiment, started in April, 1925 was Bert Mills, Cantaloupes. intended to test the effect of commercial fertilizers upon the cantaloupe crop. The soil is a river drift with a base of peaty clay. The fertility appears about average for the upper valley. Cantaloupes with an occasional green manure crop have been grown on the land for several seasons. The experiment followed the regular order determined upon for all the cooperative field trials, namely one tenth acre plats of nitrogen, phosphorus, potassium and complete fertilizer with duplicate plats for additional checking. In this field the Plats are made up of two rows the full length of the field, except that the check plats are of one row only. The first application of fertilizers was made 1924-25 in April, 1925. The stand of melons at this time was excellent and the growth throughout the season very good. Close observation failed to show any apparent differences in the growth of the vines on the various plats that could be attributed to the effect of the fertilizers. The melons from each plat were picked separately and counted. The summary of the count failed to show any significant differences between the variously treated plats or between the treated and the check plats. The experiment was repeated in 1925. This was a 1925-26 very bad season for melons, the extremely hot weather in July bringing on a sort of blight that had many of the appearances of the melon wilt such as is common in the Imperial Valley. The experimental field was so badly effected that the yield was reduced to practically nothing. No Count was made of the number of melons picked, but careful observations throughout the season failed to show any marked differences between the plats. The field was seeded to Hubam clover in October, but the stand was too poor to permit of any check being made of the residual effect of the fertilizer upon the clover crop. The crop of Hubam was plowed under in February. The season of 1937 started very inauspiciously. The 1926-27 stand of melons at the time the fertilizers were applied in March was ragged and uneven. The spring was cold and late but the warm weather came on gradually, there was a notable absence of insects and the melons made a strong normal growth. The yield was excellent. Observations were made both by Mr. Mills and myself throughout the growing and picking seasons. No differences in the color or growth of vines or in yield of melons could be detected. Count was not kept of the number of melons harvested. The need for a small tract of land upon which certain 3. c. Experimental experiments could be carried out under the complete Farm. control of the Station has been felt ever since work was started in the Las Vegas Valley. But it was not until after the passage of the Purnell Act that sufficient funds were available for that purpose. The Union Pacific Railroad was approached through Experimental Farm view of head ditch, roadway and buildings. Experimental Farm buildings. Mr. J. H. Burtner, Agricultural Agent, and Mr. Walter Bracken, Manager of the Las Vegas Water Company, regarding the loan of a tract of land and water. The request was regarded favorably and a ten acre tract on the old Las Vegas Ranch selected. This tract of virgin land was partly in mesquite, but mostly covered with a heavy growth of shad scale and other desert plants. The soil is a clay loam of fair depth, 5 to 6 feet to hardpan, and in general is fairly typical of the better class of virgin lands in the Las Vegas Valley. It is better than the poorest soils, which are hardly worthy of consideration for agricultural purposes, but scarcely as good as the better ones. It was felt that this soil was poor enough to show the effect of the fertilizers and other treatments and yet with sufficient depth and body to hold moisture and be capable of improvement. This soil is classified by the Bureau of Soils as a Spring clay loam. A typical analysis of this type of soil is given in the following table: Mechanical analyses of Spring clay loam (Copy from p.233 of soils survey of Las Vegas area) The alkali content of this soil is fairly high, one analysis of a sample taken about 600 feet from the Experimental tract showing 0.53% total alkali. The distribution, however, is very uneven, giving rise to a spotty condition in the soil. The work of putting the farm into condition was 1926—27 continued this season. An office and garage building of concrete was begun in July and finished in August. Later a machine shed was added. This building serves as headquarters for the work in this territory. It also permits the keeping of such supplies as gasoline, oils and fertilizers in a safe, dry place. Tools and equipment can be housed under lock. The office is comparatively cool and comfortable on the hottest days of summer. Such farming equipment as our funds permitted were obtained and the work of laying out and putting into production the various plats carried on. The Hubam clover that was seeded in the preceeding February was plowed under in July. The growth was quite heavy in places, making it necessary to disk it down before plowing. After plowing the field was disked, floated and furrowed for irrigating. The land was then given a good soaking and allowed to remain undisturbed about two months. When the field was then disked up preparatory to the final leveling the material turned under was found to be quite thoroughly decomposed. The final layout of the fields and plats was determined upon and the leveling of the fields completed to fit the finished Experimental Farm plowing under Hubam Clover, July 1927. Experimental Farm sour clover on series A, 1927. \ scheme. The appended drawings show the layout of the fields and plats, together with the treatments. One series of plats was ready to receive the first Series A. crop and was planted to Sour Clover in November. The weather was colder than usual for the time of year which retarded germination and several spots in the field showed a tendency to cement up and refuse to take the irrigation water. Both of these factors tended to cause an irregular stand of clover. However, by the latter part of April when the crop was turned under there was a fair crop on all the plats. After plowing under the clover the plats were re-levelled and prepared for the corn crop to follow. By the time -it was necessary to plow for the corn the green manure crop was found to be well decomposed, the field was prepared and the fertilizers applied about June 18th. Following the application of the fertilizers the ground was laid off for planting to the corn. In laying off the furrows were 1aid open rather deeply with one disk of the tractor plow, and then a stream of water turned into the furrow. This was allowed to run until the bottoms of the furrows were thoroughly wet, but was turned off while there was considerably dry soil on the surface of the ground. Then as soon as the bottoms of the furrows had dried until fairly firm the corn was dropped by hand into the wet soil. Covering was accomplished by harrowing lengthwise, of the furrows until the seed was covered lightly and then cross-wise until the furrows were well filled. A second harrowing several days later served to check the weed growth and loosen the surface soil. Practically a perfect stand of corn was obtained. It is expected by frequent cultivations to carry the crop nearly to tasseling time without further irrigation. The field for these two series were prepared, Series B and C the fertilizer applied and the seed sown in March. A good stand of Sweet Clover (Melolotis alba) was obtained on the B series but a bad soil condition combined with a spell of hot weather resulted in a rather spotty stand of alfalfa on the C series. The growth of the sweet clover has been satisfactory though some weeds and grasses made their appearance. Frequent clipping to prevent the grasses going to seed, and the stronger growth of the clover should remedy this condition. The behavior of the alfalfa plats had not been quite so satisfactory, and it is possible that the spotted condition of the stand may necessitate plowing up and rereading. Experience indicates that the depth of water used Irrigation and Soil Moisture on new raw desert soils rarely if ever gives a true measure of the duty of water for the same lands after they have been under cultivation for several years and have become thoroughly subdued. However, the amount of water used, especially when coupled with careful studies of the moisture retained in the soil after irrigations, should be of value as an indicator of the improvement of the soil condition under the several crop rotation systems and various fertilizer treatments. With these considerations in mind plans were made to measure the quantity of water applied to each plat, and to check the amount retained in the soil through moisture samples taken before and after each irrigation. Measurement is accomplished Experimental Farm head weir Experimental Farm division weir. by running the water over a weir at the head of the plats. This weir is fitted with a water stage register which gives a permanent and continuous record of the flos. The division of the main stream to the various plats is accomplished by small division weirs set in the bank of the head ditches. By setting these small weirs with their crests on an exact level a vary fair division of the stream between the various plats can be made. It is not contemplated that each plat should receive exactly the same amount of water as all the others because slight soil and crop differences make necessary some slight variations in the amount of water given. Rather the plan is to irrigate each plat in a normal manner, giving the amount of water that good practice dictates. Moisture samples are taken immediately before and as soon after irrigations as the moisture in the soil has become thoroughly disseminated. With normal applications this is usually about 48 hours after irrigating. The moisture equivalents, which were determined for each foot of each plat by the Irrigation Division of the Bureau of Public Roads, are helpful in determining when the moisture in the soil has reached a stage of equilibrium. With known volume weights it is simple matter to convert the moisture percentages into inches of water and thus to determine the exact amounts retained in the soil from each irrigation. The moisture sampling is one with an especially designed tool, somewhat on the order of a miners spoon. This tool takes a small sample, leaves only a small hole in the ground and reduces the amount of labor necessary in taking the samples. Three borings are made for each sample, the whole amount of soil from the three holes thrown together, thoroughly mixed, and the sample for the moisture determination taken from this composite. A regular order in taking the samples is followed so that successive borings are made within a very small space. The following diagram illustrates the order in which the samples are taken. An electric oven, heated to about 105 degrees, is used in drying the samples. Before starting the moisture work moisture equivalent determinations were made for each foot to a depth of 4 feet on each plat. The samples for these determinations were made with a special sample which cut a hole about 2 inches in diameter. Five borings were made to each plat as shown in the appended diagram. After the small amount of soil needed for the moisture equivalent determinations had been taken out the remainder of the sample was placed in a labelled canvas bag and stored for future chemical studies. The chemical studies should be started as soon as proper facilities are available. The volume weight determinations have proven difficult to conduct. Owing to the sticky, elastic nature of the soil the ordinary volume weight soil tube is hard to operate and the samples secured show a very wide variation in weight. With the coming of winter more time will be devoted to this feature and it is hoped that a workable method of taking the necessary samples may be developed.
- Hardman, George, Bixby, F. L, Stockwell, W. L
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- Las Vegas Valley (valley), Clark (county), Nevada , United States (nation)
Moapa Valley (valley), Clark (county), Nevada , United States (nation)
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- Chicago citation style
- Hardman, George, Bixby, F. L, Stockwell, W. L. Annual report of the Department of Irrigation, fiscal year 1926-27. 1927. Retrieved from the Digital Public Library of America, http://utah-primoprod.hosted.exlibrisgroup.com/primo_library/libweb/action/dlDisplay.do?vid=MWDL&afterPDS=true&docId=digcoll_unl_14hln/810. (Accessed November 15, 2018.)
- APA citation style
- Hardman, George, Bixby, F. L, Stockwell, W. L, (1927) Annual report of the Department of Irrigation, fiscal year 1926-27. Retrieved from the Digital Public Library of America, http://utah-primoprod.hosted.exlibrisgroup.com/primo_library/libweb/action/dlDisplay.do?vid=MWDL&afterPDS=true&docId=digcoll_unl_14hln/810
- MLA citation style
- Hardman, George, Bixby, F. L, Stockwell, W. L. Retrieved from the Digital Public Library of America <http://utah-primoprod.hosted.exlibrisgroup.com/primo_library/libweb/action/dlDisplay.do?vid=MWDL&afterPDS=true&docId=digcoll_unl_14hln/810>.