UNIVERSITY OF CALIFORNIA COLLEGE OF AGRICULTURE AGRICULTURAL EXPERIMENT STATION CIRCULAR No. 257 February, 1923 THE SMALL-SEEDED HORSE BEAN Vicia fab a var. minor P. B. KENNEDY A valuable small-seeded uniform horse bean for cover crop purposes. INTRODUCTION The purpose of this circular is to introduce to the farmers of California the small-seeded horse bean as a valuable winter green manure crop, and to a less extent as a hay, silage and grain ration crop for stock. That there is need of a legume for green manuring purposes that will grow more satisfactorily during the cool winter weather than the bitter clover, Melilotus indica, and the vetches, is well known. The horse bean has been found satisfactory as a winter grower and the only objection to it has been the excessive weight of seed required because of the large size of the type of bean on the market. The follow- ing extracts bear out this statement. Z UNIVERSITY OF CALIFORNIA EXPERIMENT STATION R. McKee in Farmers' Bulletin 969, United States Department of Agriculture (1918), says: "Various varieties of horse beans have been tested in the United States for green manuring purposes in compari- son with other legumes. Very satisfactory results have been obtained in this work in the citrus districts of California and while the crop has not been used on an extensive scale as a green manure this has been largely due to the high cost of seed. The only seed available in com- mercial markets in the United States is that of the large-seeded varie- ties and while the price per pound is comparatively low, the quantity necessary for seeding, on account of the large size of the seed, makes ^JflfeJM HBHRfe* ,y lHElfc:l*» KflRMtafttl. ^ ^QhHhB^^^^I Fig. 1. — Horse beans are well adapted for green manuring purposes in the citrus groves of Orange County. Photo taken December 30, 1922. it an expensive crop to plant. The introduction and use of small- seeded varieties would overcome this difficulty, and it seems likely that this will be accomplished in the near future." G. W. Hendry, in Bulletin 294, Agricultural Experiment Station, University of California (1918), in referring to the large-seeded type, says, "it has been employed both as a green manure and an orchard cover crop, but because of the large amount of seed required (table 9) is an expensive crop for such use. ' ' Table 9, in the above mentioned publication, gives the average num- ber of seeds in a pound as 275. Of this large seeded type, therefore, if sown at the rate of one seed to a square foot, 158 pounds would be required to cover an acre. At this rate of seeding the cost at four cents a pound would be $6.32 an acre. Of the small-seeded type (see Circular 257] TI1E SMALL-SEEDED HORSE BEAN 3 frontispiece), 75 pounds of seed or less to the acre would be required, so that the cost may be considerably reduced. (See pi. 1.) In orchards much less seed is required, depending upon the space available for cover crop planting, which varies with the age and type of fruit tree. In some instances, as in old citrus groves, one-half the area is occupied by the trees. (See fig. 1.) HISTORY OF THE HORSE BEAN The horse bean is one of the oldest cultivated plants known, since its culture extends back to prehistoric times. Large quantities of seed were found in the excavations at Troy. The origin of the horse bean is obscure, but the evidence points toward Persia as its original home. The Romans probably brought it from Persia and distributed it throughout Europe. From Europe it was brought to the eastern United States by the colonists, and to the western part of the con- tinent by the mission fathers. Horse beans were utilized by the an- eients in a number of ways. Certain sects used them in judicial pro- ceedings. If the jury cast the white form of horse bean the prisoner was exonerated ; if the black, he was condemned. Beans were also regarded as a symbol of death and on this account were not eaten by certain Egyptian priests. Because of their black spots the flowers of the horse bean were regarded as an important decoration at funerals, and the beans themselves were considered an especially appropriate food on such occasions. Pythagoras, the ancient philosopher, is said to have forbidden his students to eat horse beans because of their un- favorable dietetic properties. UTILIZATION OF THE HORSE BEAN Numerous small plantings of horse beans have been found through- out the United States and Canada, being made especially by that class of our population which comes to us from the countries bordering on the Mediterranean. As human food they are used green or dry. The plant may be made into hay or silage, fed green, or plowed under as a green manure. The beans are used as a substitute for grain in rations of milch cows, and to some extent in rations of other stock. They are also ground up and form an ingredient of some prepared poultry foods. In some instances the seed is roasted and ground and combined as an adulterant with coffee. 4 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION That the seeds are very high in protein may be gathered from the following analysis given by Woll: 1 moisture, 11.3 per cent; protein, 26.6; fat, 1.0; fiber, 7.2; nitrogen-free extract, 50.1; ash, 3.8. Harz 2 gives the composition of both the large and small seeded types on an air dry basis as follows: Large-seeded Small-seeded Per Cent Per Cent Moisture 13.00 12.75 Protein 24.23 25.41 Fat 2.28 2.01 Fiber 8.11 11.57 Nitrogen Free Extract 49.74 45.43 Ash 2.64 2.83 Fig. 2. — Vigorous leafy growth of horse beans in citrus grove between Orange and Anaheim, Orange County. Photo taken December 30, 1922. Horse beans are used quite extensively as a cover crop in some counties in southern California at the present time. (See figs. 1 and 2.) The type of large-seeded horse bean known as Windsor has been grown in California for a long time. The green pods are frequently seen in vegetable markets, and the seeds are shelled from the pods and eaten in much the same way as green peas. The plants are fed green to cattle and the dry seeds used as concentrates by dairymen. Surplus seed not utilized locally is shipped to the large eastern cities where it is used in the foreign settlements as human food. This last i Woll, F. W., Productive Feeding of Farm Animals, ed. 2, p. 363. 2 Harz, C. D., Landwirthschaftliche Samenkunde, p. 664. Circular 257] THE SMALL-SEEDED HORSE BEAN 5 use was at one time quite important, but because of the large percent- age of bean weevil, Bruchus rufimana, in the seed shipping out of the state was considerably curtailed by the rulings of the Food and Drugs Act. The present ruling with regard to interstate shipment of horse beans is as follows: "151. Horse beans: 3 The bureau will regard as adulterated interstate shipments of horse beans, otherwise known as broad beans (Vicia faba), representing the field run, which contain more than 15 per cent of wormy or weevil-infested beans. The de- liberate addition to or mixture with sound horse beans of wormy or weevil-infested beans in any amount will be looked upon as a violation of the Food and Drugs Act. The limit of 15 per cent should be regarded as tentative only and may be made more strin- gent in case further investigations warrant. ' ' Horse beans may be shipped within the State of California for cover crop purposes, provided they bear a certificate from the county horticultural commissioner that they have been properly fumigated. The weevil does not materially affect the use of the seed as a cover crop within the state. If the seed is placed in a well sealed building soon after it is harvested and fumigated for forty-eight hours with carbon-bisulfid, using 2 to 3 pounds to 100 cubic feet of space, the larvae will be killed within the seed and will not emerge. Results of experiments by DeOng show that it is possible to kill the broad bean weevil if it is exposed for five hours to a temperature of 125° F. Shorter exposures are feasible at temperatures of 140° to 170° F., but this procedure is attended with greater danger to germination. This weevil is less susceptible to heat than is the common bean weevil, Mylabris {Bruchus) obtectus, and for that reason control by fumiga- tion is commonly recommended. Aphids or plant-lice sometimes seriously injure the young plant, especially if planting has been delayed so as to cause a vigorous growth during warm weather. The remedy is to spray the effected parts with a tobacco insecticide such as black leaf 40 (Nicotine sul- fate) at the rate of 1% teaspoonfuls to one gallon of water or with 1 pound of tobacco leaves or stems steeped in four gallons of water. 3 Bureau of Food and Drugs. California State Board of Health, p. 53, Sept. 1916. UNIVERSITY OF CALIFORNIA EXPERIMENT STATION DESCRIPTION OF THE HORSE BEAN PLANT The horse bean plant is an annual legume belonging to the vetch group, with erect coarse stems and large leaves without climbing tendrils. The leaves, consisting of from one to three pairs of large oval leaflets, (see fig. 3), are distributed from the base to the tips Fig. 3. — Horse beans have large leaves and succulent stems. This plant is only three weeks old. Circular 257] THE SMALL-SEEDED HORSE BEAN of the stems. The white or purplish flowers, with their spots verging on black, are borne in clusters on short stalks in the axils of the leaves. In the small-seeded types from two to five pods develop from a cluster of flowers, while the large-seeded types bear only one or two Fig. 4. — A typical root of horse bean with its many lateral branches. The strong central tap root on decaying leaves channels of humus in the soil. Fig. 5.— The small- seeded horse bean has an unusually large number of pods per plant. This single stalk has 64 pods. pods in each place. There is usually one strong central root (see fig. 4), with numerous spreading lateral rootlets. These may or may not be covered with nodules, according to whether there are suitable bacteria in the soil or not. The size of the plant varies very con- 8 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION siderably according to the variety, climate, soil, rate of seeding and methods of culture. A growth of three feet may be expected on average orchard soils, and seven or more feet under favorable soil, moisture, and temperature conditions. The large number of tender ^^S^^^ v x^^^9ka \ I W- 'ASM* 4 Fig. 6. — Horse bean roots are well supplied with numerous large nodules. (Enlarged.) Circular 257] THE SMALL-SEEDED HORSE BEAN 9 leafy stalks to a plant and the taller growth greatly favor the small- seeded horse bean for green manure purposes. There are about sixty pods (see fig. 5), to a stalk on the small-seeded type, and only about fifteen pods to a stalk on the large type. The average number of seeds in a pod is about the same for both types, viz., three or four. The seed of the small horse bean is oval or nearly round and about one-fourth to three-eighths of an inch long, while that of the large horse bean is more or less strongly flattened and about one inch long. Great variation in size exists among the different strains, grading from very large seeds to very small ones. (See pi. 1.) A similar con- dition obtains with regard to the color of the seeds, which ranges from black to purple and green with various shades of brown pre- dominating, in both the large and small-seeded types. The weight of the commercial small-seeded Bell horse bean, No. 37, (see table 1 and pi. 1), is sixty-four pounds to a bushel, and that of the commercial large-seeded horse bean, No. 3, fifty-two pounds to a bushel. The Bell bean is uniform in size and can be seeded with a bean planter, while the large commercial horse bean varies very considerably in size, so that the seeds may be broken or the planter gets clogged. Because of this difficulty the large-seeded horse beans are usually sown broad- cast. This type of sowing entails the use of a larger amount of seed than when a planter is employed and usually results in the seeding of from one-third to one-half of the desired amount of ground only. The orchardists commonly sow about ninety pounds to the acre, but they would prefer to sow 125 pounds if the cost were not so great. INOCULATION OF THE SOIL To obtain the full benefit from a legume it should have on its roots nodules (see fig. 6) that contain the bacteria which enable the plant to use the free nitrogen of the air. Without these nodules the legume will take most of the nitrogen for its growth from the soil, thus depleting rather than replenishing or increasing its nitrogen content. The horse bean belongs to the vetch group 4 so that in most in- stances it will be found that the bacteria it requires are in the soil. Should there be any doubt, however, the soil or seed should be inocu- lated. One method is to obtain soil from a field that has recently grown horse bean plants known to have had nodules on their roots. * Kennedy, P. B., Legumes as Organic Fertilizers in California Agriculture. Univ. of Cal., Agri. Exp. Sta. Circular 255, 1922. 10 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION This soil is sprinkled over the land at the rate of about 200 pounds an acre and immediately harrowed in, or it may be mixed with several times its weight of soil taken directly from the field to be planted and drilled in. Another method is the soil suspension method. It consists in placing the soil containing the proper bacteria in a tub or barrel and mixing it thoroughly with two to three times its volume of water. The mixture should be agitated vigorously with a shovel several times a day for one or two days. After that the soil should be allowed to settle and the liquid, which will contain the organisms poured or dipped off. The seed as it is contained in sacks should be dipped in this liquid for a sufficient length of time, say about ten minutes, or it may be sprinkled with the liquid, after which it should be spread out to dry, preferably in the shade. Where the soil to be used has to be shipped this method is easy, effective, and less costly. A third method of inoculation is to use one of the many commercial products for the inoculation of legumes. On making application for the bacteria the kind of crop to be seeded should be stated. Full directions accom- pany the material. CULTURE OF THE HORSE BEAN Horse beans are not exacting in regard to the type of soil they require, but they do best on well-drained heavy silt or clay loams. They will also do fairly well on sandy soils, provided there is ample moisture. Seed several years old germinates as well as new seed, so that there is no necessity for increasing the rate of seeding if old seed is used. The time to sow the seed for cover crop purposes under irrigation is September, October, or November, the exact preference, among the three months, if there is any, not having been fully demon- strated. In localities with severe winters of ice and snow, spring plant- ing must be practiced. The plant flourishes in cool frostless weather (fig. 7), and dislikes the summer heat of our interior valleys. Under the latter circumstances it is also more subject to fungus and insect at- tacks. Seeding may be done by machine or by hand. An ordinary field bean planter may be used for the small horse bean, and a lima bean planter for the large horse bean. A corn or sorghum planter may also be used by providing a special plate when it is used for beans or by filing the grooves or holes to suit the size of the seed. The rate of seeding varies from 195 pounds for the large commercial horse bean (see No. 3, table 1 and pi. 1), to 79 pounds for the small commer- Circular 257] THE SMALL-SEEDED HORSE BEAN 11 cial horse bean (see No. 37, table 1 and pi. 1). This computation is made on the basis of one plant for every square foot when the bean is used as a green manure. For beans used in seed production, where cultivation is necessary, the rows should be 3 feet apart and the seeds placed from 8 inches to 1 foot apart in the row. (See fig. 8.) For beans used for green manure purposes on land under irrigation cultivation is not necessary, but if the land is so badly infested with weeds that they would choke the young horse bean plants, cultivation Fig. 7. — Small-seeded horse bean plantings flourishing in the cool coast climate of San Gregorio, San Mateo County, California. 12 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION should be given them during the early stages of their growth. Under conditions where there is not an ample supply of water for irrigation, care should be taken to plow under the green material at an early date so as to allow for plenty of moisture in the soil to aid in the decomposition of the green manure. The plowing should be done early, even if the green manure crop has not attained the desired height, as permitting it to grow and further rob the soil of moisture will have a detrimental effect both on the soil and the crop being grown, or to be grown, on the land. This precaution is especially Fig. 8. — A dense stand is produced for seed purposes by sowing in rows 3 feet apart. necessary where the green manure crop is being grown with the natural precipitation as the only moisture supply. If the crop is being grown for its seed care must be exercised or a large amount of seed will be lost through shattering. The seed crop may be cut by hand, with an ordinary mower, or with a drop-rake reaper. The field should be cut when the lower pods are fully mature and the upper ones well developed, but not yet ripe. A cloudy day or early morning while the plants are still moist should be selected for mowing. Shocking may be done by hand the same day. (See fig. 9.) When the crop is sufficiently dry, the small-seeded horse bean may be threshed with an ordinary bean thresher without difficulty, a process which usually requires several days of bright weather. The large- seeded types are more difficult to thresh with a machine, the rolling process being found more satisfactory. A yield of from one to two tons of cleaned seed an acre may be expected. m a ikjii 3 ? m - ITS o -I S3 - pg Plato 1. — Variation in sizes of d I • + * 9 o* rs« © O ' :" ^ : brent types of horse bean seed. Circular 257] THE SMALL-SEEDED HORSE BEAN 13 WORK OF THE CALIFORNIA AGRICULTURAL EXPERIMENT STATION As early as 1903, Stubenrauch reported test plot experiments with horse beans to be used for green manuring purposes. Of the 8 varie- ties tested at the Amador Foothill substation at Jackson, only 2 proved to be too tender to warrant further trials. The lowest tempera- ture recorded was 21° F, which occurred in February. Only 2 of the varieties tested proved to be sufficiently frost resistant to serve Fig. 9. — The windrows of horse beans are being placed in bunches to prevent excessive shattering. for winter growth in the foothills. The estimated yield of green stuff to the acre was 11,003 pounds for No. 7943, and 9,755 pounds for No. 7035. At the San Joaquin Valley substation near Tulare, which is located on land containing more or less alkali, in the case of experi- ments made during an exceptionally cold winter, the horse beans were disappointing and produced comparatively low yields. The plots were all irrigated, but were sown too late. The two best varieties were No. 1453 which produced 7,481 pounds and No. 1454 which produced 8,348 pounds to the acre. At the Southern California sub- station at Chino, San Bernardino County, the horse beans were the most promising green manure plants tested, making a rapid winter growth. No. 7943 produced the highest yield, with 44,528 pounds of 14 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION green stuff to the acre. These estimates were calculated from weigh- ings of the growth on one or two square yards, and may perhaps be considered maxima in all cases. The heavy succulent root growth was particularly noticeable, and it assisted greatly in opening up the soil and adding materially to the humus. At the central station at Berkeley sixteen varieties were planted. The experiments there demonstrated that horse beans require from about ten to fourteen days to germinate, the length of time being dependent upon the season when they are grown. The date of planting was October 28, and the green stuff was plowed under about the end of March. The test plots demonstrated that the horse bean was one of the most promising of winter-growing legumes for green manure purposes, giving the highest yield of green stuff on record. The estimated yields of green stuff calculated from small weighings were as follows: No. 1454, 68,970 pounds to the acre. 121 No. -T^r 58,624 pounds to the acre. No. 7942, 55,750 pounds to the acre. No. 1453, 51,727 pounds to the acre. EXPERIMENTS MADE AT THE UNIVERSITY FARM AT DAVIS Plantings of 23 varieties were made at Davis in the fall of 1916 and 31 in the fall of 1917. Most of the seed for these test plots was secured from the office of Grass and Forage Plant Investigations of the United States Department of Agriculture. They were grown without irrigation and planted in December 11 and 12, 1916, and December 22, 1917. The growth of the different varieties when they were in blossom, about May 1, ranged from 18 to 36 inches. This is a small growth and indicates that Davis is not very well suited to the growing of horse beans without autumn irrigation. The beans were found to be especially resistant to frost injury. The leaves, although frosted at night, would recover during the day. There were from 10 to 24 pods on each plant, with an average of 3 seeds in a pod. The lowest yield of seed to an acre was estimated to be 1150 pounds and the highest 1830 pounds. No weights were taken to estimate tonnage for green manure. The growth and yields obtained at Davis are very much less than those obtained on the coast, where there is more rain- fall and the winter conditions are less severe. Circular 257] THE SMALL-SEEDED HORSE BEAN 15 INFLUENCE OF THE WEIGHT OF SEED ON THE RATE OF SEEDING The chief drawback to the extensive use of horse beans as a winter cover crop has been the large size of the seed ordinarily obtainable on the market, which makes the rate of seeding prohibitive. Table 1 shows Fig. 10. — Height of small-seeded horse beans at the time of harvesting for seed. that the largest seed, No. 1, weighs 3.13 grams. A pound, therefore, would contain 145 seeds, and the rate of seeding necessary in this case would be 300 pounds to the acre. This calculation is based on a rate that would allow one plant to every square foot of ground, or 16 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION what we would consider an ideal spacing for a cover crop. The method of seeding proposed is to plant the beans in two-foot rows with the seeds placed 6 inches apart in the row, or if it is more convenient they might be sown in rows 1 foot apart with the seed 12 inches apart in the row. It has been proved in our test plots that the size of the seed does not influence the size of the plants, the smaller seeds having a tendency to produce plants with a greater number of stems. No. 64, table 1, the smallest of the seeds, weighs only 0.12 gram and gives 3775 seeds to the pound, so that only 11% pounds of seed an acre would be required. Our experiments are being conducted with a view to selecting No. 64 so as to introduce it into the seed trade. The cost by the acre to the fruit grower would then be very considerably reduced. Taking the commercial horse bean as No. 3 (pi. 1, table 1) with 223 seeds to the pound and a requirement of 195 pounds to the acre, the cost at 4 cents a pound would be $7.80 an acre, while No. 64 (pi. 1 table 1) at ll 1 /^ pounds an acre and 10 cents a pound would cost $1.15 per acre, or if the beans could be raised for 4 cents a pound, the cost would be 46 cents an acre. Comparing the small-seeded horse bean with vetch at 6 cents a pound, with a requirement of 70 pounds of seed an acre, the cost would be $4.20 an acre. To all appearances there is a discrepancy in plate 1, a seed which is apparently smaller in some cases preceding a larger one. The table and illustration, however, are based on the weight of the seeds, so that while No. 30 appears larger than No. 29, by actual weight it is less. Table 1. — Influence of weight of seed on rate of seeding: Wt. of 1 seed No. of seeds *Lbs. required Number in gms. per lb. per acre 1 3.13 145 300 2 2.37 191 228 3 2.03 223 195 4 1.97 230 189 5 1.91 237 183 6 1.82 243 179 7 1.78 254 171 8 1.66 273 160 9 1.64 276 157 10 1.64 276 157 11 1.63 278 155 12 1.61 281 154 13 1.58 287 152 14 1.49 304 143 15 1.49 304 143 16 1.39 326 133 ]7 1.38 328 132 * Seeding rate figured on cover crop basis with one plant per square foot on area actually sown to cover crop. Circular 257] THE SMALL-SEEDED HORSE BEAN Wt. of 1 seed No. of seeds *Lbs. required Number in gms. per lb. per acre 18 1.37 331 131 19 1.27 351 122 20 1.22 371 117 21 1.20 377 115 22 1.15 394 110 23 1.14 397 109 24 1.12 404 107 25 1.06 427 102 26 1.03 440 99 27 1.02 444 98 28 1.01 448 97 29 .97 467 93 30 .93 487 89 31 .92 492 88 32 .91 498 87 33 .88 515 84 34 .87 520 84 35 .87 520 84 36 .85 533 82 37 (Bell) ( .82 552 79 38 .81 560 78 39 .79 573 76 40 .75 604 72 41 .73 620 70 42 .69 656 66 43 .60 755 57 44 .58 781 56 45 .56 809 54 46 .53 855 51 47 .50 906 48 48 .48 944 46 49 .46 985 44 50 .45 1000 43 51 .43 1053 41 52 .42 1078 40 53 .40 1132 38 54 .38 1190 36 55 .36 1258 34 56 .35 1294 33 57 .34 1332 32 58 .31 1461 30 59 .31 1461 30 60 .25 1812 24 61 .22 2060 21 62 .18 2516 17 63 .17 2664 16 64 .12 3775 11.5 17 * Seeding rate figured on cover crop basis with one plant per square foot on area actually sown to cover crop. 18 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION CO-OPERATIVE EXPERIMENTS A small-seeded type of horse bean has been grown for home use at San Gregorio, San Mateo County, for thirty-five years, the seed having been brought originally from England by Jesse Palmer. Two years ago his grandson, Frank P. Bell, decided to multiply the beans on a field scale for cover crop purposes. (See fig. 10.) Up to this time the horse bean commonly grown in the vicinity had been the large flat Windsor type. Mr. Bell's plants were examined in the field and Fig. 11. — The small-seeded horse bean attains a height of more than when ready to cut for hay. feet a number of different forms, all small-seeded but varying very consider- ably in size of seed, leafage, number of pods on the plant and flower characters, were found. With a view to standardizing some of these, selections have been made with two main objectives in view — size of seed and amount of leafage. The field run of the Bell type is represented by No. 37, table 1, plate 1. These beans are now being grown on a commercial scale on heavy soil without irrigation. A Black Hawk planter is used for seeding after filing the ridge off as is shown in seed plate No. F348. Any corn or bean planter could be used by adjusting the seed plates. The rate of seeding was 25 pounds an acre, the rows being 3 feet apart with the seed 12 inches apart in the row, which is a sufficient space for seed purposes on good soil, but not for a cover crop where Circular 257] THE SMALL-SEEDED HORSE BEAN 19 maximum leafage is desirable. The date of seeding was December 12, 1921. The plants were well up and the rows showing by December 28. The full blossoming period was about April 10, 1922. The fields were being cut for seed on July 20, and the plants averaged 6 feet in height. (See fig. 11.) Estimates from small weighings of plants taken June 26 indicated 20 tons of green stuff to the acre. Other plantings made in February and March, 1922 matured seed in August. COMPOSITION OF THE GREEN MATERIAL The following analysis (table 2), were kindly furnished us by the Division of Nutrition. The samples were gathered in the field and represent three stages in the growth of the small horse bean. Table 2. — Analyses op Green Material, Small-seeded Horse Beans Sample No. Date of Seeding Moisture per- centage Protein per- centage Ether Extract per- centage Ash per- centage Crude Fiber per- centage Nitro- gen Fr. Ex. per- centage Condition of Growth, June 26 3953* Dec. 12, 1921 79.43 3.51 0.37 1.10 4.41 11.18 Height 75 inches Pods, no blossoms 3952* Feb. 12, 1922 83.38 3.55 0.46 1.23 3.72 7.66 Height 53-60 inches Blossoms and pods 3951* March 25, 1922 86.59 3.00 0.59 1.34 3.28 5.20 Height 40 inches Blossoms, no pods * Samples taken June 26, 1922. The analyses show that the percentage of moisture is greatest when the plants are in blossom, decreasing as they reach maturity. Figured on a dry basis, the percentage of nitrogen would be 2.72 for No. 3953, when the plants were past the blossoming period; 3.37 for No. 3952, when the plants had both blossoms and pods; and 3.58 for No. 3951, when the plants had a large number of leaves and blossoms but no pods had been formed. The amount of nitrogen contained in 100 pounds of the material would be .56 for No. 3953, .57 for No. 3952, and .48 for No. 3951 ; or approximately % pound of nitrogen for every 100 pounds of material turned under. Estimating the yield of green material as 20 tons an acre, we would be adding to the soil approximately 200 pounds of nitrogen an acre. 20 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION These figures represent the nitrogen in the tops of the plants only and do not include a considerable amount of it which is present in the roots with their nodules. Sample No. 3953 from the crop planted on December 12, 1921 was taken June 26, after the blossoming period, when the plants were 75 inches high with their pods well filled. Sample Fig. 12. — Horse beans and oats make a palatable and nutritious silage. No. 3952 from the crop planted on February 12, 1922 was taken June 26 when the blossoms and pods were about equally represented and the plants were from 53 to 60 inches high. Sample No. 3951 from the crop planted on March 25, 1922 was taken June 26, when the beans were in blossom with no pods present and the plants were 40 inches high. Circular 257] THE SMALL-SEEDED HORSE BEAN 21 SILAGE FROM THE SMALL HORSE BEAN In order to determine whether horse beans would make good silage, some green material grown at San Gregorio without irrigation was chopped up when well podded, after the blossoming period, and mixed with 50 per cent of red oat hay in the milk stage and pressed into a barrel. (See figs. 12 and 13.) This was done on June 26, 1922. On opening the barrel on November 19 the contents were found to be moulding on top and the side, owing to the air's getting in at the ■3 a ^t \V -^s.w5^99hiNh - \ \ A ' H^HBSi^j H -• ^T^^M Fig. 13. — The material is coarse, but analyses show that it is very high in protein. cracks in the sugar barrel. The remainder of the material was in excellent condition, however, moist, with all the leaves whole and not disintegrated. The characteristic silage odor was present. In table 3 below, the composition of the small-seeded horse bean and oat silage is compared with two of our commonly used silage crops, Indian corn and sweet sorghum. The analyses made there indicate that the horse bean and oat silage is higher in protein than either Indian corn or sweet sorghum. The nutrients may be made more comparable by reduc- ing the material to a dry basis, which would give 13 per cent of protein for horse bean and oats, 9.9 for Indian corn and 6.6 for sweet sorghum. The percentage of fat on the same basis would be 4.1, 2.6, and 2.0 respectively. 22 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION Table 3. — Comparison of Horse Bean and Oat Silage with Indian Corn Silage and Sorghum Silage Moisture per- centage Protein per- centage Fat per- centage Ash per- centage Crude Fiber per- centage Nitrogen Fr. Ex. per- centage Acid percentage Sample Volatile Fixed 5 Small-seeded Horse Bean 73.00 3.51 1.12 2.07 6.25 14.00 0.38 1.08 6 Indian Corn 73.07 2.69 .71 2.06 5.72 15.75 0.41 2.09 7 Sweet Sorghum 78.27 1.44 .45 1.85 6.80 11.20 0.51 1.22 5 Analyses kindly made for us by the Division of Nutrition, s, 7 Woll, F. W., and Voorhies, E. C. Trials with California silage crops. Bull. 282, Calif. Agr. Exp. Sta., 1917, p. 24. The experiment demonstrated that it is quite feasible to make silage of excellent quality from red oat hay and horse beans. As the inhabitants of the region involved are engaged to a large extent in dairying and this crop is raised without irrigation, the building of silos and the filling of them with horse beans and green oats for silage would be a practicable method of providing succulent material throughout the year. In this connection we quote the following from the Pacific Rural Press of December 16, 1916, "My experience is that green horse bean plants are beneficial. Several years ago I broadcasted a mixture of horse beans and barley in my young orchard. It made a good growth, and before plowing in the spring I cut and fed it. The cows cleaned it up well and increased their milk. We noticed no bad effects on the milk or cream. I have noticed that both the cows and the hogs prefer the green barley or alfalfa to the green horse beans. "The same time I fed the horse beans I put part of it in the silo with a filling of alfalfa, but did not find any difference when I fed it out. I believe that horse beans green would make good silage. The cured horse beans are fine grain for dairy cows. They will increase the milk flow and the quality of the cream. ' ' W. J. Hanna, Gilroy, California. Circular 257] THE small-SEEDED HORSE BEAN 23 DECOMPOSITION OF THE GREEN MANURE Little definite field knowledge is available with regard to precisely what takes place when organic matter is incorporated with the soil. In loose warm moist soils quantities of available nutrients may be produced in from two to four weeks, the maximum amount occurring in from four to twelve weeks. Martin 8 concludes from his experiments that the more succulent the green manure the more readily it decays and therefore the more quickly the nutrients are available. If the green material is incorporated with the soil at a half mature stage, it produces the largest yields of subsequent crops. He recognizes three periods in connection with the breaking down of the organic matter : 1. The accumulation of humus in the soil. 2. The decomposition of the humus and the production of nitrates. 3. The rapid decrease of the humus. SUGGESTIONS The small-seeded horse bean should be grown as a winter green manure crop in the orchards of the Santa Clara Valley and similar sections, in the grape and citrus sections of southern California, and in all parts of the state which have a moderate winter climate. In the coastal regions which are not adapted to the standard silage crops, Indian corn or sorghum, the small-seeded horse bean should find a valuable place in the cropping system of those engaged in the dairy industry. Truck gardeners in the coastal sections, in the Imperial Valley, and in other sections of the state near the cities, are finding it more and more difficult to obtain organic fertilizers. The small- seeded horse bean may aid in solving their difficulty. 8 Decomposition of green manures at different stages of growth. Bulletin 406, Agr. Exp. Sta., Cornell University, Aug. 1921.