Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. Bad bi PEN:: OFT ELE USDEPARTMENT OPAGRICULTURE & (BA No. 10 ye Contribution from Office of Experiment Stations, A. C. True, Director. October 30, 1913. PROGRESS REPORT OF COOPERATIVE IRRIGATION ~ EXPERIMENTS AT CALIFORNIA UNIVERSITY FARM, DAVIS, CAL., 1909-1912. Mortars By S. H. BECKETT, : i lel ane : , Irrigation Engineer. f Y os e | / f oY De © # f INTRODUCTION. fi) at aces { The experiments herein described were planned and carried out for the purpose of determining the water requirements of Various stand- ard crops. For the purpose a tract of 25 acres on the University farm at Davis was set aside by the college of agriculture. The work was planned and carried on by the irrigation investigations of the Office of Experiment Stations, in cooperation with the department of en- gineering of the State of California, the California Experiment Sta- tion furnishing seed and a part of the labor in return for the crops. The University farm, comprising 779 acres, les one-half mile west of the town of Davis. The soil, which is typical of that of a great portion of the Sacramento Valley, is classed as Yolo loam, described by the Bureau of Soils of this department, as follows: The surface soil of the Yolo loam consists of a dark-brown loam of light to rather heavy texture. The soil is usually free from gravel. Below a depth of 24 inches the subsoil is generally made up of strata of silty loam or sandy loam. At greater depths this rests on clay loam or clay..* * #* Owing to the excellent drainage and comparatively open texture of this type it has proved to be well adapted to fruit, including peaches, almonds, prunes, and grapes. * * * While irrigation has not been in general use, it has been found to be beneficial to the tree and fruit where the lower strata of the soil lack the close texture and compactness necessary for the retention of mois- ture. It is one of the best general-purpose soils in the region and is adapted to a wide range of crops.* The mean annual rainfall, although slightly below the average for the Sacramento Valley as a whole, amounts to 16.54 inches, the greater part of which comes in December, January, February, and March, while from May to October very little rain falls. A mean temperature of 77.9° F. is recorded for the month of July, the mean +U. 8S. Dept. Agr., Bur. Soils, Field Operations, 1909, Eleventh Report, pp. 1657, 1658. 6137°—Bull. 10—13 1 - 2 BULLETIN 10, U. S. DEPARTMENT OF AGRICULTURE. minimum of 47.6° F. occurring in January. The maximum tempera- ture recorded is 112° F., and 16° F. has been registered as a minimum. These extremes are exceptional, however. As a preliminary step in starting the experiments at Davis, a 12- inch well was sunk near the northeast corner of the tract and a 4-inch horizontal centrifugal pump, directly connected with a 74-horsepower motor was installed, thus insuring a reliable water supply. Water was delivered to the various checks and field laterals through 8-inch galvanized-iron slip-joint pipe. When properly fitted together this was practically watertight, eliminating loss in transportation. Before starting each irrigation the discharge. from the pump was measured over an 18-inch Cippoletti weir, and the measurements were used in computing the amount of water applied. IRRIGATION OF ALFALFA. Operations were started in 1907, and in the fall of that year the major portion of the tract was leveled for alfalfa irrigation. Border, rectangular, and contour systems of checks were used, and at the time it was intended to rely upon the open-ditch system of the Yolo County Consolidated Water Co. for water. The accompanying sketch (fig. 1) shows the system of checks and ditches installed, the acreage of each check, ane its number, which will be used in future designation. During the whole of 1908 the land stood idle. Early in March, 1909, piete 1 to 28, 32, 33, 34, and the west half of 35, 36, and 37 were thoroughly disked, cross-disked, harrowed, and seeded to alfalfa, 2 pounds of Utah seed per acre being used. oO a z S w 5 «i he Aw A *, Lae IRRIGATION AT UNIVERSITY FARM, DAVIS, CAL. 13 - Were further conclusions to be drawn each season should be con- sidered separately, but in each case inspection of the value column will show that for each of these three seasons irrigation of grain was made to pay. IRRIGATION EXPERIMENTS WITH INDIAN AND EGYPTIAN CORN IN 1910 AND 1911. For this work, which extended through 1910 and 1911, the 4-acre tract lying directly north of the west end of check 87 was used. During 1909 this tract was in sugar beets, and previous to that for a number of years it had been in grain. In the spring of 1910 it was plowed twice—March 1 and April 9— harrowed, and cross-harrowed. On April 29 the west 2 acres were seeded to Yellow Dent Indian corn and the east half to Egyptian corn (white durra), a sorghum. In seeding a corn’ planter was used and the rows were placed 40 inches apart. During*the season of 1910 no definite time for irrigation was set or definite quantities assigned, both being controlled by the needs and conditions of the growing crops. INDIAN CORN. Immediately after planting the field was divided into four plats, the water being applied as shown in the following schedule: Schedule of irrigation of Indian corn, 1910. Number of plat. Number of irrigations. | Date. aoe ted, | | | Inches ies Seb S kSS SoS ee eee INIOVIVE aig He oper Pe es iret ge ae AM ee os Coe eae [pees ene otal Pay score tt ate Ds Eb5ee = 8 Saas hoe Een eaae O)TIC Se ee Sra tr ever hoe: nay i ee Oe 24 3533 Wise sesce 3.3 ee TWO... .------- 22-22-2222 22 eee eee eee eee iuly 13 2.0 |(May 26 4.4 Ae eee Soe aE age ene disse eee ease BDRCC wc e as ment eascieheiice seem sneer ewan joane 24 Qed. \(\July 13 1.5 Thorough cultivation followed each of these irrigations, and at all times the field was kept free from weeds. In the middle of August, when the corn was in the milk, it was cut, weighed, and fed green. After the crop was removed the land was fall plowed, harrowed, and allowed to stand idle through the winter. The following March it was again plowed, harrowed, and seeded to * Yellow Flint ” corn and the experiment of 1910 repeated. The area was divided into four plats, which received the following amounts of water during the growing season. 14 BULLETIN 10, U. S. DEPARTMENT OF AGRICULTURE. Schedule of irrigation of Indian corn, 1911. ~ Depth of Number of plat. ee of Date. water Status of corn. gations. applied. a Inches 1 ee Sie ae ie INOMe@ = DRE Cs |E Lest pane Cl oan omer eee : OE RSE Geet ame ee eee One aaaes June 22 2.3 | Corn 20 inches high: 3 Two Nui 21 2. 2 KOC age picnic iaur ween ata || aoe a. Mehr re July =— 17 2.5 | Corn coming in tassel. jJune 21 2.3 | Corn 20 inches high. Aa incnie ane 2k imhreeseess July 17 2.4 | Corn coming in tassel. Aug. 8 2.4 | Corn coming into the milk. In each of these irrigations the furrow method was used, a small stream running in each furrow for a long period, thus avoiding flooding and, as in previous seasons, a thorough cultivation following each irrigation. August 16 and 17 the corn was harvested, weighed, chopped, and stored for winter use. | 2 3 The following table shows the results obtained for the two seasons: Summary of results of irrigation of corn. Value at | Cost of Season. ee Number of irrigations. | Depth. ee er! $2.50 irriga- Bot | * | per ton. | tion. } | Inches Tons. AD WeNOM G22 hk eet UR ee a oe a ed Sea eee | PRR 6.85 Cel) Week Seok. 1910 | Di SOMOS Fea eee oe a 3.3 8. 85 22003 $1. 50 Seis nici se tie Gite =o Se SDS O tn Gere A Oe oe ae eee | a3 10. 05 74ay J 2.60 | AUN reas ce: Ee a | 8.0 10. 45 26. 13 3.90 SAN MC Soh sn Sop ese ee ote een Nee epee ea Fa 3. 67 ON183 Gea 1911 YAP OW oY baheatenet et sates ted a CE CRE See 3.0 4. 86 L205 1. 40 wert eeese reese SAT wor ere. hae ke ern 4.8 5.21 13. 03 2. 45 | PW Ha Be 0 a2) = alee Renee ss etre Sea coe A | eal 6. 59 16. 48 3.65 Note.—Cost of irrigation taken at 30 cents per acre-inch for water and application, plus 50 cents per acre per irrigation for furrowing. The most noticeable feature in these results is the decrease in yield in 1911, when compared with the yield in 1910. This is due entirely to the character of the season. The late spring of 1911 was abnor- mally cold and very unfavorable to the production of a good yield, even in the presence of an abundance of moisture. During 1910 one and two irrigations were applied to advantage, while ihe third irrigation just before harvesting produced an increase of but 0.4 ton per acre green weight, and was spplied at a loss. The season of 1911 shows light yields and small increases, and if interest on the investment in pumping machinery and cost of leveling the land be added to the cost of irrigation no financial gain would be realized. EGYPTIAN CORN. This investigation followed along the same lines as the investiga- tions with Indian corn, the preparation of the land, time of seeding, and entire procedure being the same up until the time of the first IRRIGATION AT UNIVERSITY FARM, DAVIS, CAL. 15 irrigation. It was noticed, however, that the Egyptian corn (white durra) was much slower in coming up, and in the early stages of growth developed very slowly, especially during the cold spring weather of 1911. The area originally was divided into three plats, No. 1 containing 0.9 acre; No. 2, 0.46 acre; and No. 3, 0.67 acre. About the middle of June it was seen that the yield from the unirrigated plat, No. 1, was going to be small, and it was then subdivided into plats 1-A, 1-B, and 1-C, of 0.3 acre each. Plat 1-A was not irrigated, plat 1-B re- ceived one irrigation, and plat 1-C two irrigations. Following are the dates of irrigation and the quantities of water applied: Schedule of irrigation of Egyptian corn, 1910. Number of plat. | EE oe oie Date. | Depth. | Status of corn. i _ Inches Ate eae ee ce INOnOM ae at sea emcees ee teh 1B aes sage ast ONE aaa. eee ao 15 | 3.75 | comes inches high. .-- do 3.75 0. 1-C...-. 2.222222 ee | TWo..-..-..-.---- {iuiy 14 1.75 | Corn forming heads. DRM es. 882 Ones eat | July 13 3.10 | Do. 3 Tie ae 28 3.25 | Corn 4 inches high. THRE LS he ee ae Re ee July 14 2.10 | Corn forming heads. During 1911 the experiment was repeated on the same soil. The first seeding on April 18 was a failure, and only about one-fourth of a stand came up. The plat was replowed, harrowed, and reseeded May 13 and a good stand obtained. The area was then divided into four equal checks and the following irrigation schedule outlined : Schedule of irrigation of Egyptian corn, 1911. Number of plat. ent aes | Date. | Depth. Status of corn. | | Inches a ee INON GTS Hote ee TRG iy ene | Pema tae ae Sal Be AN a Reef. Onewe atte eS | June 21 1.8 | Corn 6 inches high. 3 Te ‘ doe EN: 2.6 a Do: ; ES 1 rae |: a ae ee July 18 2.0 | First heads forming. June 22 2.3 | Corn 6 inches high. Co ae ene IEATreeeee ean eee fouls 18 1.9 | First heads forming. Aug. 8 1.5 | Corn in the dough. In all irrigations the furrow method was practiced, the water being applied in alternate furrow spaces. A thorough cultivation followed each irrigation, and the whole area was kept free from weeds during both seasons. In harvesting, which occurred the first of October, the heads were picked, hauled, and thrashed, and later the stalks were cut with a mowing machine. 16 BULLETIN 10, U. S. DEPARTMENT OF AGRICULTURE. The following table shows the results of the two seasons’ work: Summary of results of irrigation of Egyptian corn. Z se Value at Cost of Season ESIaE ‘ Number of irrigations. Depth. ¥ st $1.50 per | irriga- : ; 100 pounds.) tion. Inches. Pounds. I-A None-22. 2. 2 ee eee 1,335 $20: 03 >| -2o2e ei cB spain OnelAk. Bice = 2S eeu aye fa) 2,670 40.05 $1.52 AOIQis. es Ae IGE TWO SPS ee ee ee eee 5. 50 27 40. 50 2.65 2 See Onan a. ne ee 3.10 2° 510 37. 65 143 [BEaae ae WO? Les ce Se ee ee 5.35 3,340 50. 10 2.60 (3 Mee INOHE: < Seo ee eee eee Eee eee 1,100 16:50; 5250 a KIYIs [) ote e Bice 2 egg Ec. ae Orie te ok a eee Been 1.8 1,690 25.35 1. 04 E E Stee SUS oe WG See. eee eee eee ae ete 4.6 2, 650 39.75 2.38 “ee RATES. oe ae Pees ee eee a5 T/ 2,964 44.48 3.20 Note.—Cost of irrigation is taken as 30 cents per acre-inch for power and attendance, plus 50 cents peracre per irrigation for furrowing. The accompanying diagram (fig. 5) shows the results for 1911, platted graphically, the yields with the corresponding amounts of water apphed being shown. With this crop, as with the Indian corn, a greater yield is pro- duced in 1910, with less amounts of water applied, than in 1911, due entirely to a warmer spring and much more favorable growing season. The results for 1910 show but a small variation in the yields from plats 1-B, 1-C, and 2, and a large increase in plat 3. This is due to the time of irriga- tion, plat 3 receiving one early and one midseason irrigation, the first apphed before any effects of drought were shown, thus keeping more or less of a constant moisture percentage in the soil during the entire period of growth. In 1911 the yields increased quite uni- formly with the increased amounts of water appled, until the third irriga- tion, when there was a slight falling off. When this last irrigation was applied the heads were fully formed and the grain ripening, and the only effect of this irrigation was probably in preventing any pinching or shrinking in the grain. Inspection of the value column for each season shows that the irrigation of this crop may be made to pay, even if 6 per cent interest on an investment of $50 per acre for leveling the land and developing water be added to the cost of irrigation. Here, as in the irrigation of other grain crops, no definite duty of water can be established. The amounts of water required and the time of irrigation will always vary with the season, and the intelli- WATER APPLIED-INCHES | o | 18 | 46] 57 | ul ce oO <= om ul oa (op) Q z => Oo jae = (A ay “Wl = Fie. 5.—Yield of Egyptian corn with different quantities of water. IRRIGATION AT UNIVERSITY FARM, DAVIS, CAL. Ave gence of the irrigator along these lines is always going to be the con- trolling factor in success and failure or profit and loss. That the time of applying water is of as great importance as the quantity of water applied is shown plainly in 1910, in plat 1-C, where two irri- gations followed in close succession and the increase in yield due to the second irrigation did not pay for the cost of the irrigation. IRRIGATION AND CROP ROTATION EXPERIMENTS IN 1912. It was decided in the fall of 1911 to turn under a part of the alfalfa as green manure, and in the spring of 1912 to start a crop rota- tion of grain, sugar beets, corn, and potatoes, following alfalfa, these crops to be investigated from an irrigation standpoint, showing the increase in yield, with the increased amounts of water apphed. Com- parison also was to be made with the returns obtained from the un- fertilized soils in previous years. Early in November, 1911, plats 1 to 15 and 32 to 37 were plowed to a depth of 8 inches with a two-gang plow. At this time the alfalfa had about a 6-inch top growth, and a good covering of green manure was turned under. Following this plowing the land was harrowed, cross-harrowed, and disked, leaving it in a finely pulverized condition to receive the winter rains. On February 1, 1912, the land was replowed to a depth of 6 inches, harrowed, and cross-harrowed. Owing to the light winter rains the green manure had not thoroughly rotted, although the soil turned up in a fine, mellow condition, presenting the appearance of recently hav- ing been given a heavy application of rotted stable manure. Owing to the checking system of plats 1 to 15, it was necessary to relevel them for furrow irrigation. This area was later seeded to sugar beets, Indian corn, and Egyptian corn. GRAIN FOLLOWING ALFALFA. Following the replowing and harrowing on February 1, the east halves of checks 32, 33, and 34 were seeded to 60-day oats, 75 pounds of seed per acre being planted. At the same time the west halves of these checks were seeded to Australian white wheat, at the rate of 85 pounds of seed per acre. All of the seed was drilled in, the drills running lengthwise with the checks, and a good stand came up on all of the checks. 18 BULLETIN 10, U. S. DEPARTMENT OF AGRICULTURE. The following plan of irrigation was outlined and carried out: Schedule of irrigation of grain following alfalfa in 1912. OATS. Number of plat. Number ofirrigations. Date. Depth. Status of oats. Inches. SDE Ste om eee Se INone<<2. + tsa ee en ee ee 3 Apt eee One os nae April 9---- 13.2 | Oats 12 inches high. fApril 13... 13.2 O. Se aie ie a Ge May 10. .-- 7.2 | Oats heading out. WHEAT. Sede ns gee Saar ae INONG 2252 aoa oe eee eee See at set oy hues One fae 2 ee April 25... 10.00 | Wheat 24 inches high. 34 Two fApril 15... 9.15 | Wheat 18 inches high. Ie ig age ran ae Sake dest pe TIM BYio 8.40 Wheat coming into full head. Tn each irrigation water was added at a time when it was thought that the best results would be obtained, and in no case was irriga- ong be L2trrgenens | | 4 c -S = -\ - C = Fic. 6.—Yield of oats and wheat, with different quantities of water. tion delayed until the crop was suffer- ing for moisture. It will be noticed that in all cases large amounts of water were used. This was necessary in order to cover the checks completely and was due to the open, porous con- dition of the soil, the result of turn- ing under the green manure. Early in June, just before harvest- ing, several days of heavy north wind occurred, badly shattering both crops, and it was estimated that 30 to 40 per cent of the grain was lost. This loss is not included in the table of yields. June 15 all plats were cut with a binder, stacked in the field, and later thrashed with a stationary thrasher. The table following shows the yields in hay and grain in pounds per acre, the quantity of water applied, and the cost of irrigation. The accompanying diagram (fig. 6) shows the yields of grain platted with the corre- sponding amounts of water applied to each check. IRRIGATION AT UNIVERSITY FARM, DAVIS, CAL. 19 Summary of results of oats and wheat irrigation. ‘Yield per acre. Grain x5 Number} Numberof | pepih Fine value at ue of P- of plat. irrigations. pt. ae $1.50 per ti a Hay. Grain. 8 * | 100 pounds. ; Inches. | Pounds. | Pounds. | Per cent. Be aacoae INOTe es Re Seen eer 1,380 435 31.8 SONU ES eee cane ater ied N33 tee ten Oneness aa 13.2 4, 900 1, 420 28. 0 21.30 $3. 96 Oy ae ene ae UNiOadus scares 20. 4 5, 820 2,040 35.1 30. 60 6. 12 By ata IN OTE we ye reroll ee se eae 1, 730 560 32.4 Sed Ores aS Wheat....... Bonn ate One ee Ss 10.0 3,920 1,210 30.9 18.15 3.00 Cy elas ale Twos eseues eee 18.4 6, 300 1,935 30.8 29.03 5. 52 NoTE.—Irrigation cost figured at 30 cents per acre-inch for power and attendance. With the oats the single irrigation of 13.2 inches increased the yield 225 per cent, giving a gain in returns of $14.77 per acre, at a cost of $3.96 per acre for irrigation. Two irrigations, totaling 20.4 inches, increased the yield 370 per cent, with a gain of $24.07 per acre in grain value, at a total cost of $6.12 per acre for water and attendance during irrigation. Figuring on the same basis with the wheat, one irrigation of 10 inches increased the yield 116 per cent, with a gain in returns of $9.55 per acre, at a total increased cost of $3 per acre. Two irrigations increased the yield 245 per cent, giving an increase in returns of $20.63 per acre, at a total expense of $5.52 per acre. It will also be noted that in all cases the percentage of grain to hay remains about the same, showing the grain production to increase uniformly with the total weight of matter produced, No definite conclusions can be drawn from this one season’s work. A decided advantage, nevertheless, is shown in favor of irrigation. All of the water was applied at a financial gain, and an idea is obtained of what may be accomplished in years of light rainfall when conditions are unfavorable to dry-land farming. SUGAR BEETS FOLLOWING ALFALFA. Following the early spring preparation of checks 1 to 15, the land was replowed on February 22, then harrowed and cross-harrowed. The area was divided into seven plats, 5, 6, and 7 to be seeded early, and 1, 2, 8, and 4 seeded later. March 11 the first plats were seeded in drills 20 inches apart, 15 pounds of Wankaka seed per acre being used. March 27 the remaining checks were seeded in the same manner. Spacing, thinning, and hoeing followed when the beets were in the third and fourth leaf, and this was followed by .a thorough cultivation. The dates of irrigation depended upon the needs of the crop, and sufficient water was added to give the soil a thorough wetting. The furrow method of irrigation was practiced, the water being applied in alternate spaces between the rows, and as nearly as possible the water was confined to the furrows and kept away from the beets. 20 BULLETIN 10, U. S. DEPARTMENT OF AGRICULTURE. As long as the size of the beets permitted, thorough cultivation fol- lowed each irrigation, and all plats were kept free from weeds. Following are the dates of irrigation and the amounts of water apphed: Schedule of irrigation of sugar beets in 1912. : ¥y é Number - Se es ae Depth Time of seeding. of plat. Number of irrigations. | Daie. snpled: | | ra a a = : . Inches. 5 (3 ONG: s2. 2h. kes F. See See Ae Be ts Marly Mar, adie 2 22-2 ees et Dy MBSE 5s Seek [4252 e hs Soe 555s May 21 10.5 | - lh és May 21 9.2 Lae Ran aos apaarpe eee June 21 4.4 1 ENO eee Se ee elo cio ee 2 On xc eint Me Soe i ee SE ee | May 24 6.1 z | - \[May 26 6.1 Meera Mar eso eee | 3) EO. es 3a ss SS Ses5 TPE, ST 54 May 24 6.1 A CERTee 2 ee! 5b Sk a eee \