JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND Maataloustieteellinen Aikakauskirja Vol. 58; 83—101, 1986 Goat’s rue (Galega orientalis Lam.), a potential pasture legume for temperate conditions EERO VARIS University of Helsinki, Department of Plant Husbandry, SF-00710 HELSINKI, Finland Abstract. In this paper, a perennial legume Galega orientalis Lam. (goat’s rue), is presented. This unselected forage legume originating from regions with a Mediterranean climate, grows well in North-European conditions in Finland. It seems to be very persistent and produces yields that equal or even exceed those of red clover in quantity and quality. The trials on management practices and feeding carried out at the University of Helsinki are reported here. The research will be continued on mass selection for low alcaloid and fiber contents, seed production and use of grass-mixtures for making hay or silage. Index words: Galega orientalis, goat’s rue, pasture legume 1. Introduction Intensification of the use of legumes has been widely studied in Finland during recent years. In addition to attempts to improve the management of traditional crops, such as red clover, pea and field bean, research has been devoted to potential new legume species. Of the few newcomers that seem to be adapted to the northern Finnish climate, one of the most promising appears to be Galega orientalis Lam. (goat’s rue). Its better known relative, G. officinalis L. (goat’s rue, French lilac), is used as an ornamental and medicinal plant, and occurs as a weed. Goat’s rue was brought to Finland from Estonia, where its cropping and quality char- acteristics have been widely studied from the beginning of the 1970’5. At the Department of Plant Husbandry of the University of Hel- sinki, field trials were started in 1978. At the same time the Departments of Microbiology and Animal Husbandry commenced micro- biological and feeding studies. The research projects reported here were led by the author and mainly carried out by P. Kansanen and T. Kortesmaa at the Department of Plant Husbandry, by K. Lindström at the Depart- ment of Microbiology and by M. Jauho at the Department of Animal Husbandry. Financial support was given by theFinnish Academy of Sciences in 1979—1981 and by the SITRA Foundation in 1981—1984. In this paper, the botanical characteristics, 83 https://www.c-info.fi/en/info/?token=HEgTmxUVF0-_VtL1.AMTJJzp5L-al7ne2D37BBA.gvNoyXkGoq9AC2K7oCR5QxTs9-N5u92URqq5CZ9I2FnnoaO8xVkcKIvOkLHu4qOP2cjJZMnOoqvlL-ZbENJI_Hmsw948EEgAfK06DRaqe5H8dXr3PplXxsLBqjZkOrVhSqPYC6vSRoSbsC6ame9nqbd-4yfMQIK0 results of crop management trials and feeding characteristics of the plant are given. The ex- perience obtained in Finland is supplemented with reports found in the literature. More detailed results have been reported in Finnish (Kansanen 1983, Lattu 1983, Jauho 1984, and Mäkäräinen et ai. 1985). 2. Origin and distribution The legume genus Galega is generally con- sidered to consist of six species indigenous to the warm temperate regions from Mediterra- nean Europe to Iran, and the mountain re- gions of tropical East Africa. The origin of the plant is not certain, but it is thought to have been brought to Europe from the Near East by Arabs or Hungarians. Later, G. officinalis was taken to South America and New Zea- land, where it became a harmful weed (Hegi 1924, Tutin et ai. 1968, Milne-Redhead and Polhill 1971, Willis 1973). 3. Botanical characteristics G. ohentalis develops into a bush with 10—18 stems of a height of 50 —150 cm. The stem is hollow and branches in the upper part. The stipules are ovate and 1 —1.5 cm long. The numerous leaves are 14—25 cm long and consist of 9—15 oblong acuminate leaflets 3 —6 cm long. There are a few pubescent flower clusters on the stem, containing 20— 25 blue-violet, sometimes white, 1-cm long flowers. Goats’s rue is a cross-pollinating plant, flowering for 18—25 days. The pods are 2 4 cm long and contain 3—7 kidney-shaped seeds. The weight of a thousand seeds is 5.5 — 9.0 g. The seeds are yellowish green in colour, later light brown (Komarov 1963, Tutin et ai. 1968, Raig 1980). Goat’s rue has a long root system, reaching to a depth of 60—80 cm. In the seeding year it consists of the main root and its laterals. In the early autumn, 2—lB stolons grow from the root collar, first extending horizontally under the soil surface and then turning up- wards to form new shoots. The underground stolons are important, for new goat’s rue plants develop from wintering stolon buds. When the parent plant dies, the shoots that have developed from the underground stolons grow additional roots and become indepen- dent plants. With the help of the stolons, a thinned plant stand can attain a normal growing density of 400 —450 stems/m2 (Raig 1980). Goat’s rue is able to fix nitrogen in associa- tion with Rhizobium bacteria. The nodules can be separated into three groups according to their shape. Two kinds of nodules can be found in the top soil, namely, unbranched oval and branched nodules. Deeper in the soil, only smaller, flat nodules occur. The number of nodules ranges between 400 and 1500/plant depending on the growth factors and soil con- ditions (Proctor and Moustafa 1962). The Rhizobium which nodulates Galega species is not related to the major groups of rhizobia infecting other legumes and forms a specific taxonomic group within the genus. Although the Rhizobium of pea (Pisum sati- vum) infects the roots of goat’s rue, the sym- biosis is ineffective (Lindström et ai. 1983). As nitrogen fixation is closely related to the metabolism of the host plant, the air tempera- ture and other growth factors greatly influence the activity of the nodules (Lindström 1984). 4. Utilization 4.1 Forage legume In the 19th century G. ohentalis was little known as a crop plant, except in Russia, where it was appreciated as a source of honey. Crop- ping experiments started in the 1920’s in Rus- sia. In the beginning of the 1970’s goat’s rue seeds were collected from different parts of the Soviet Union and more intensive research was started in several places (Raig 1980). 4.2 Soil improvement Goat’s rue is suitable for soil improvement 84 and green manuring. As it has a large root system, it enriches the soil with large quantities of good organic matter. Thus, the plant im- proves both the texture and the nitrogen bal- ance of the soil. In Estonia the favourable ef- fect of goat’s rue was observed to last for 2—3 years. In a 30-cm-thick soil layer the root system of goat’s rue left 3.8 times more dry matter, 3.6 times more potassium, 2.7 times more calcium and 5.0 times more nitrogen than the root system of timothy (Raig 1980). In addition, goat’s rue was reported to reduce plant diseases, pests and weeds, though couch grass (Agropyron repens) proved able to com- pete with goat’s rue (Raig 1980). 4.3 Honey plant Goat’s rue is pollinated by insects and is attractive to both honeybees and bumblebees. Because of its early flowering, it complements the selection of honey plants in early summer. In seed production experiments, it was found that placing bee hives in the field increased seed yields from 180—400 kg/ha to 670 kg/ha in unfavourable pollination conditions (Raig 1980). 5. Growth requirements 5.1 Light Goat’s rue is very intolerant of shading in the sowing year. Shading also impairs the overwintering ability, makes the stand thinner and improves weed growth. Because goat’s rue has a high light demand, the sward is usually established without a cover crop. Goat’s rue is sensitive to shading in later years as well. On the other hand, its large photosynthesizing surface and long growth period allow effective use of radiation and result in abundant dry matter yields (Raig 1980). The optimum plant density for vegetative production is 400—450 shoots/m 2 . In seed production, a thinner stand is recommended, since goat’s rue needs more light for abundant flowering and seed formation (Raig 1980). 5.2 Temperature G. orientalis germinates at s—6°C,5 —6°C, but the optimum temperature is 10—12°C (Raig 1980). It can endure an air temperature of —4O°C under snow cover and —2O°C in a bare field. During the growing season, the leaves tolerate —5 to —7°C without any reduction in yield. Low spring temperatures, however, can decrease the growth and nitrogen fixation (Raig 1980). 5.3 Water G. orientalisresists drought fairly well. Its water requirements are said to be between those of lucerne and red clover. High ground water and flooding are harmful, but goat’s rue can withstand spring floods reasonably well for up to 12—18 days (Raig 1980). The strong root system permits good utiliza- tion of autumn and winter water reserves in the soil, so that the first harvest is not depen- dent on the spring rainfall. If a water deficit occurs, however, the aftermath is small, for the leafy stubble also consumes water (Raig 1980). 5.4 Soil Goat’s rue grows best in light soils, where the stolons can spread out effectively. Soils rich in humus or sandy soils are preferred. The optimum pH is near neutral, but a pH range of 5.6—6.0 also allows good yields (Raig 1980). According to results from Estonia, the Rhizobium bacteria of goat’s rue cannot fix nitrogen below pH 5.6 (Raig 1980). In labo- ratory conditions in Finland, however, the rhizobia were active at pH 4, though theplant itself did not thrive in this acidity (Lindström et ai. 1985). 6. Establishment of a goat’s rue stand The procedure in establishing a stand of goat’s rue is similar to that for red clover, but goat’s rue has some special characteristics that 85 shouldbe taken into account. Heavy soils are not suitable and in the seeding year goat’s rue develops slowly and is susceptible to shading from other plants. For effective nitrogen fixa- tion, it is also absolutely necessary to inoculate the seed. 6.1 Manuring and biological nitrogen fixation High dry matter yields of goat’s rue take up large amounts of potassium, phosphorus and calcium; a dry matter yield of 10 t/hacon- tains 290 kg potassium, 44 kg phosphorus, and 180 kg calcium (Raig 1982). In acid soils, liming may improve the availability of nu- trients. Farmyard manure can be used, but nitrogen fertiliser is recommended (Raig 1980, 1982). Applications of small amounts of lime (1—2 tons/ha) just before sowing have promoted germination and development of nitrogen fixation (Raig 1980). The nodules on goat’s rue do not develop until the end of the seeding year, but when active they make it self-sufficient with regard to nitrogen. A goat’s rue sward inoculated with an effective Rhizobium strain needs an annual fertiliser application of 40 kg P/ha and 100 kg K/ha (Raig 1980). At the Department of Microbiology of the University of Helsinki in 1983—1984, the in- fluence of environmental conditions on the Rhizobium bacteria and the nitrogen fixation of goat’s rue were investigated. According to the measurements of nitrogenase activity, the nitrogen fixation of goat’s rue was equal to that of red clover. In the seeding year, the nitrogen fixation of both test species started at the end of July, but in later years it started in early spring. The nodules were most active in August, after which the nitrogenase activity declined towards the end of the season. Ni- trogen fixation generally ceased a little earlier in the autumn in goat’s rue than inred clover, the rhizobia of which were active until the be- ginning of October. In the long term, the nitrogenase activity was positively correlated with the growth rate of the plants; in the short term, the nitrogenase activity reacted strongly to changes in the environmental conditions, including air temperature (Lindström 1984). Rhizobium bacteria are suggested to be sensitive to acid conditions. Experiments per- formed in Finland to compare nitrogen-fixing goat’s rue with plants receiving mineral nitro- gen in five different acid soils showed that acidity had the same effect on the yields of the symbiotically grownplants as on theplants receiving mineral nitrogen, which suggests that the sensitivity of the symbiosis to acidity did not limit plant growth even under very acid conditions. It was also concluded that goat’s rue, its symbiotic nitrogen fixation and the rhizobia are tolerant of moderately acid agri- cultural soils. Severe winters may reduce bac- terial numbers in the soil, because the nodules are sensitive to low temperatures (—5°C) (Lindström et ai. 1985). 6.2 Seed preparation Half of the total seed yield of goat’s rue can consist of hard seeds, whose germination can be improved by acid treatment or mechanical scarifying. In Estonia the seeds were soaked in concentrated nitric acid for I—21 —2 hours to soften the coats (Raig 1980). In Helsinki, seeds have been scarified mechanically. The germination of goat’s rue seeds varies in different years. Seed produced in Finland has had fairly high germination; for example, in 1982 after the mechanical treatment it was 82 + 4 %. The Rhizobium species infecting goat’s rue does not occur in Finnish soils and inocula- tion with the appropriate rhizobia is thus es- sential for successful cultivation. Orginally, Estonian strains were used, but the Depart- ment of Microbiology has now undertaken to provide an effective domestic Rhizobium strain for goat’s rue. 6.3 Sowing 6.3.1 Sowing time and depth It is recommended that a goat’s rue sward 86 be established early in the spring, when the seedlings can utilize the spring moisture in the soil. When sown early, the plants also have time to become sturdy before the winter. In Estonia the best results have been ob- tained from seedings during the first two weeks in May but in cold springs sowing must be delayed until the beginning of June. This can reduce yields in the first two years. Seeding in June-August is not recommended in Estonia (Raig 1980). In most soils a sowing depth of 1.0—1.5 cm is usually sufficient, but it is generally best to sow 1 cm deeper, to assure proper germina- tion. Early growth is suppressed when seed is sown deeper than 2.5 —3.0 cm (Raig 1980). 6.3.2 Seeding rate The utilization of the ley determines the sowing rate. In Estonia a row spacing of 20—30 cm and a seeding rate of 30—40 kg/ha are recommended for a sward for fodder. For seed production, a wider row spacing (60— 90 cm) and a lower seeding rate (7—10 kg/ha) are recommended (Raig 1980). In Finnish field trials, a seeding rate of 40 kg/ha has been shown to give the maxi- mum yields. However, in our conditions a row spacing of 12—14 cm seems to be better than wider ones. The effect of the seeding rate was evident in the two first years; later, the environmental conditions and management practices become more important (Kansanen 1983, Mäkäräinen et ai. 1985) (Fig. 1). 6.4 Cover crop During the sowing year the development of goat’s rue is very slow, the yield is small and the stand is easily overgrown by weeds. To in- crease the yield in the establishing year and to suppress the weeds, a cover crop seemed to be necessary. At the Department of Plant Husbandry two series of trials were carried out to test various cover and companion crops for goat’s rue. In the first trial series in 1978—79, the highest dry matter yields in the seeding year were ob- tained from a sward where Italian ryegrass was used as a cover crop (Table 1). The lowest yields were obtained from the plots without a cover crop or with timothy as a companion crop. In the next summer, plots with red clover grew best and produced the highest yields. Barley as a cover crop was most detri- mental. Unfortunately, the trial field was bad- ly damaged by an ice cover during winter 1979—80. In the second trial 1979—80, five cover/ companion crops were compared. (Fig. 2). In the sowing year, the plots sown with red Fig. I. Effect of the seeding rate on the total DM yield from goat’s rue swards in successive years (establishment year ex- cluded), 1980—1983 (Mäkä- räinen et ai. 1985). 87 Table 1. Effect of various cover and companion crops on the DM yields of a goat’s rue sward. Aver- ages for different densities of cover/companion crops. Seeding year 1978, Ist year sward 1979; 75 kg/ha N applied every spring. Two cuts per year (except for red clover, barley and sward without cover crop in sowing year) (Mäkäräi nen et al. 1985). Cover/companion crops DM yields kg/ha 1978 1979 Total T. resupinatum 3 280 b 4 180 a 7 460 T. pratense 3 480 b 6 680 c 10 160 L. muttiftorum 4 580 c 5 720 b 10 300 H. vulgare not available 3 490a G. orientalis alone 2 140 a 5 930 b 6 070 such as barley, Persian clover and Italian rye- grass. The ryegrass survived winter 1978—79 and this exceptional overwintering is the rea- son for the favourable results obtainedwith it in the first trial series. The trials were too short to establish definitely which of the cover/ companion crops is the most suitable, but from the experience gathered we can conclude that in the long term the best way to establish a pure goat’s rue sward is to sow it without a cover/companion crop. If necessary, weeds can be controlled with herbicides, and in this way a productive, long-lasting sward can be established. clover produced most and the plots without a companion crop and those with timothy least. In the next year the timothy grew as well as the red clover, but the highest total yields were obtained from the plots sown with red clover. Italian ryegrass and Persian clover suppressed the growth of goat’s rue too much, leaving behind a very poor stand. In the sowing year all cover/companion crops impaired the development of goat’s rue and the harvested yield consisted mostly of the cover/companion crop. The goat’s rue was suppressed most strongly by annual crops, 6.5 Goat’s rue timothy mixtures Being a legume, goat’s rue contains more protein and less sugar than grasses. Its low sugar content complicates the use of a pre- servative in silage making and impairs the palatability of the silage. To improve the quality of the silage, trials were carried out in which goat’s rue was grown as a mixture with grasses. The mixture also competes better with weeds in the sowing year. According to Estonian studies, mixed stands produce more than pure goat’s rue stands, especially in acid soils. Timothy, orchard grass (Dactylis glomerata) and meadow foxtail (Alopecurus Fig. 2. Total DM yields from the sowing- and Ist-year sward of goat’s rue established with various cover/companion crops. Trials from years 1979—80. No nitrogen was applied (Mäkäräinen et ai. 1985). 88 tenuis) have proved suitable for mixing with goat’s rue (Raig 1982). In Finnish trials in 1981—1984, goats rue timothy mixtures were studied applying a 2-cut system (Kansanen 1983, Mäkäräinen et ai. 1985) (Table 2). Without added nitrogen, mixtures of tim- othy and goat’s rue gave higher dry matter yields than pure stands of goat’s rue or tim- othy. Nitrogen application encouraged the growth of timothy and weeds. The composi- tion of the mixtures changed as the sward aged. In the beginning, the proportion of tim- othy in the yield was higher than expected from the seed mixture. In the 3rd and 4th year, the proportion of goat’s rue started to in- crease. The proportion of weeds was 12 % in the sowing year and lower in the second year, but started to increase when timothy became sparse, especially in plots where nitrogen was applied. The higher the proportion of goat’s rue in the mixture, the higher were most of the crude protein yields. In the last year the crude pro- tein yield was highest in sward with 60 % goat’s rue in the mixture. This mixture also produced the highest dry matter yields. Nitro- gen application improved the crude protein yields significantly only in the two first years and the improvement was greatest in pure timothy stands. The crude protein contents of the yield in- creased as the proportion of goat’s rue in the mixture increased. Nitrogen application raised the protein content significantly only in the first cuts in 1981 and 1984 (Table 3). In gen- eral, the crude protein content was slightly higher in the first cut than in the second. Table 2. Total DM and CP yields from mixed stands of goat’s rue and timothy in 1981—84 (Mäkäräinen et ai. 1985). Mixture P. pralense DM CP G. orientalis kg N/ha kg N/ha % kg/ha . % kg/ha 0 120 0 120 100 30 25 680bc 23 543 a 4 638 d 4 454 b 80 24 20 2 26 244bc 26 792ab 4 089 c 4 434 b 60 18 40 4 27 619 c 27 057ab 4 291cd 4 310 b 40 12 60 6 24 561be 29 296 b 3 775 c 4 088 b 20 6 80 8 22 797bc 24 378ab 3 093 b 3 193 a 100 10 16 379 a 25 205ab 1 521 a 2 969 a Mean 23 880 26 045 3 568 3 908 N Mix N xMix N Mix N xMix F-value ns *** ** ns *** •** HSDo.o, 3 577 kg 5 058 kg 479 kg 677 kg Table 3. Crude protein contents from mixtures of goat’s rue and timothy in 1981—84 (Mäkäräinen et ai. 1985). Mixture P. pralense 1982 1983 1984 G. orientalis % kg N/ha kg N/ha kg N/ha % 0 120 0 120 0 120 100 0 19.8 19.7 19.8 21.5 15.5 16.6 80 20 15.0 16.8 16.8 19.0 14.4 14.2 60 40 12.8 14,8 17.0 18.7 14.3 13.8 40 60 13.9 13.0 16.1 18.0 14.5 11.7 20 80 11.8 12.1 13.6 16.1 13.6 11.8 0 100 10.8 11.9 9.6 14.9 8.3 8.6 Average 14.0 14.7 15.5 18.0 13.4 12.8 89 The crude fibre contents did not correlate with the proportion of goat’s rue in the mix- ture as clearly as did the protein contents. Usually pure goat’s rue stands, or stands in which goat’s rue predominated contained most crude fibre. Nitrogen application had no effect on the crude fibre content (Table 4). The sugar contents of the yields depended on the proportion of timothy in the mixture, improving significantly when it increased (Fig. 3). Nitrogen application had no effect on the sugar content of the yields. It can be concluded that a mixture of goat’s rue and timothy in which the proportion of goat’s rue is more than half can produce high dry matter yields even without nitrogen applications. In the first two years applied nitrogen may have a positive effect, but in later years the proportion of goat’s rue in- creases and nitrogen applications are not required. The composition of the mixture af- fects the quality of the yield more than the quantity. When the proportion of timothy in the mixture increases, the crude protein con- tent decreases and the sugar content increases, in spite of nitrogen applications. The com- position of the mixture has no pronounced ef- fect on the crude fibre content. 7. Cutting times 7.1 Number of cuttings Only one cut of G. orientalis is possible in the seeding year, but in subsequent years two or three cuts are possible. In Estonia, higher protein and dry matter yields were obtained with three cuts (Raig 1980), but two cuttings were better for overwintering (Jartijeva 1977). Cutting three times may disturb the Table 4. Crude fibre contents of mixtures of goat’s rue and timothy in 1981—84 (Mäkäräinen et ai. 1985) Mixture P. pro- 1982 1983 1984 G. orientalis tense ~ ~~ ~ ~~ Ist cut 2nd cut Ist cut 2nd cut Ist cut 2nd cut 100 0 24.0 29.9 31.2 25.6 29.4 32.3 80 20 27.8 27.6 29.3 26.1 27.4 30.1 60 40 27.4 27.4 27.7 24.6 27.3 33.0 40 60 27.8 26.6 28.4 23.0 27.6 30.7 20 80 27.8 25.9 29.3 22.0 27.0 30.9 0 100 28.4 26.3 29.0 26.1 26.2 26.5 Average 27.2 27.3 29.2 24.6 27.5 30.6 90 Fig. 3. Sugar contents of mixtures of goat’s rue and timothy in 1981—84 (Mäkä- räinen et ai. 1985). 4 stolon growth and the storage of carbohy- drates (Raig 1982). In the preliminary trials at the Department of Plant Husbandry in 1978—79, two cuts were found be more ap- propriate for Finnish conditions (Kansanen 1983) and the 2-cut system was applied in all the trials reported here. 7.2 Time offirst cutting The dry matter yield of goat’s rue increases until the full flowering stage, but the quality of the yield is better when it is harvested be- fore flowering (Raig 1982). The time between the first and second cutting should be long enough for formation of the stolons, so that delay of the first cutting can hazard the over- wintering and the first cut yield in the fol- lowing year (Raig 1980). In 1980 a three-year trial was established at the Department of Plant Husbandry to in- vestigate the effects of the times of first cutting on the yields of goat’s rue (Kansanen 1983, Mäkäräinen et ai. 1985 (Table 5). The after-effect of the cutting schedule is seen only in 1982. There are some indications that when the first harvest takes place early (16. 6.), at the beginning of flowering, in the previous years, the sward produces best in the long term. The results of root analyses also indicate that, for proper development of stolons, 70 days is a suitable interval between cuttings. 7.3 Time of second cutting The date of the autumn cutting affects over- wintering and also the yield and its quality, as goat’s rue keeps growing until late autumn. Cutting too early encourages the growth of the stolon buds and increases winter damage; regrowth after cutting also consumes the car- bohydrate reserves of the plant. In Estonia, postponing the autumn cutting from the middleof September to the middle of October increased the yields in both that and the fol- lowing year. The most unfavourable cutting timewas the end of August, which is the time recommended for red clover (Raig 1982). Two series of trials were carried out at the Department of Plant Husbandry to investigate the effects of autumn cutting times on the yields of goat’s rue. The results from the first series, in 1979—1983, are given in Figure 4. In the seeding year, the treatment 20. 8./ 5 cm was not harvested, which is probably why it yielded exceptionally well in 1980. In later years, the late autumn harvest was regularly better than the earlier one. The stubble height had no clear effect on the yields. Some results of a second trial series in- corporating five autumn cutting times in 1981—83 are given in Table 6 and Figure 5. The results obtained are similar to those from Estonia in that the following year’s yield was greater if the stand was cut late in the previous autumn. Overwintering was also im- Table 5. Effect of the date of Ist cutting on the DM yield from goal’s rue leys in 1980—1982 (Mäkäräinen et ai. 1985). Time of the Ist cut Time Total DM yield between Ist and 2nd cut 1980' 19812 19823 1980—82 kg/ha 2nd cut kg/ha % kg/ha % kg/ha % 5. 6. 83 3 010 103 5 910 83 4 540 90 13 470 16. 6. 72 2 720 93 5 750 81 6 070 120 14540 26. 6. 60 3 040 104 7 770 109 4 880 96 15 680 8. 7. 50 2 890 99 9 120 128 4 760 94 16 770 x 2 920 =lOO 7 140 =lOO 5 060 =lOO 15 120 Cut only on 5. 9. 2 The 2nd cut on 29. 8. 3 The 2nd cut on 15. 9. 91 Table 6. Effect of the date of 2nd cutting on the DM and CP yield (kg/ha) from goat’s rue leys in 1981—1983 (Mäkäräinen et ai. 1985). Cutting time in autumn DM CP Total Total1981 1982 1983 1 18. 8. 16. 8. 18. 8. 17 564ab 3 131ab 2 26.8. 31.8. 29.8. 15 764 a 2 950ab 3 7. 9. 9. 9. 9. 9. 16 271ab 2 860 a 4 22. 9. 23. 9. 27. 9. 19 634 b 3 484 b 5 5. 10. 5. 10. 3. 10. 19 150ab 3 365ab x 17 677 3 157 F-value * * HSDq qs 3 668 kg 591 kg 92 proved and more stolons were formed. The quality of the autumn yield decreased with delayed cutting time, and, as expected, the protein content was lower and the crude fibre content higher. In Finnish conditions, the least suitable time for the second cut seems to be the end of August, and a favourable timeseems to be the second half of September. 7.4 Combinations of cutting times In 1983, a series of trials was established Fig. 4. Effect of the date and height of 2nd cutting on the DM yield from 2 to 5-year-old goat’s rue swards (Mäkäräi- nen et ai. 1985). Fig. 5. Crude protein content (% DM) of goat’s rue leys in autumn 1981—1983 (Mäkäräinen et ai. 1985). Table 7. Total DM yield (kg/ha) from goat’s rue leys in 1983—85. Cutting time Cutting time in the summer x in the autumn 46 6 . 19. 6. 24. 8. 8 275 10 271 9 187 9 961 9 423a 7. 9. 12 268 13 191 13 235 13 298 12 998 c 16. 9. 10 741 12 421 12 883 13 303 12 337 c 5.10. 10 332 11 595 11 861 12 414 11 551 b x 10 404 11 869 11 792 12 244 11 577 b F-value Autumn cut *** HSD00s 718 Table 8. Total crude protein yield (kg/ha) from goat’s rue leys in 1983—85. Cutting time Cutting time in the summer x in the autumn 4.6. 11.6. 19.6. 28.6. 24.8. 2 557 3 297 2 777 3 051 2 921 7.9. 3 511 3 821 3 998 4 176 3 876 26.9. 3 155 3 838 3 623 4 116 3 683 3. 10. 2 966 3 677 3 514 3 690 3 462 x 3 047 3 658 3 478 3 758 with different combinations of Ist and 2nd cutting times. The results are presented in Tables 7 and 8. The total dry matter yields seem to be best when the first cutting was done before full flowering, in the second half of June, and the second cutting in mid September. With these dates the quality of the yields is also good. The earliest cutting times proved to be unsuitable both in summer and in autumn. The effect of the cutting date on the quality of the yields was similar to that in other experiments: the fibre content was higher and the protein con- tent lower when the crop was cut late. 8. Yield 8.1 Quantity of yield In the seeding year, the development of the overground parts of goat’s rue is slow and cutting can be done in late autumn only. At this time the sward is about 40—60 cm high. The yield of goat’s rue in the seeding year is significantly smaller than that of red clover grown under the same conditions. The root system of goat’s rue grows vigor- ously in the sowing year and in the autumn, the dry matter yield of the roots may be three- fold the dry weight of the tops. Goat’s rue does not flower in the seeding year unless sown very early. The seed yield of the sowing year, if any, consists mainly of hard seed (Raig 1980). In the second year, the growth of goat’s rue, partly from stolon buds, begins much faster than in the sowing year. The growth rhythm is about two weeks earlier than in red clover. In Estonia, goat’s rue swards have proved to be very permanent, being highly productive for 7—15 years. In good conditions the yields have been as high as 13 tons per hectare (Raio 1982). In our five-year experiment at the Uni- versity of Helsinki the yield was highest in the third year (Fig. 6). The yield level of 6000—7000 kg DM per hectare was not so high as that recorded in Estonia. In a variety trial at the Sata-Häme research station 200 km north of Helsinki, the yield from a Ist-year goat’s rue ley in 1984 was 6420kg DM per ha, or 67 per cent of the yield 93 of the best red clover variety, Venla (Mäkä- räinen et ai. 1985). The same was true in University trials but, in later years, the yield from goat’s rue clearly exceeded that of the other legumes tested, because red clover and lucerne did not overwinter properly. 8.2 Quality of yield 8.2.1 Chemical composition The chemical composition of goat’s rue is similar to that of otherperennial legumes such as red clover and lucerne (Table 9). At the University of Helsinki, some of the quality characteristics were measured in 1981 and 1982 (Fig. 7). The crude protein content in goat’s rue was somewhat higher than in red clover at the same development stage. The protein content also decreased more slowly in goat’s rue, but goat’s rue had a higher crude fibre content than red clover. The differences in quality between the sum- mer and autumn yields varied, depending on the cutting schedule. The differences may be quite small (Table 10), but the percentage of crude fibre may be high in a late autumn cutting. Sixteen amino acids have been isolated from goat’s rue. According to Jartueva (1977), the amount of amino acids in the dry matter decreases with developing senescence, but their proportions remain unchanged. No reliable comparisons have been made between the amino acid contents of goat’s rue and other legumes. According to our results, goat’s rue con- tained significantly less potassium, calcium and magnesium than red clover. The phospho- rus content was about the same in the two species (Table 11). Table 9. Prebloom composition (% DM) of G. orientalis, G. officinalis, T. pralense and M. saliva (Mäkäräinen et ai. 1985). G. orien- G. offid- T. pro- M. sotiva3 lalis‘ nalis2 tense1 Dry matter 27.017.0 15.021.0 Ash 9.5 7.7 10.0 10.0 Crude protein 18.9 20.0 18.0 21.0 Fat 2.7 3.2 4.0 3.0 Crude fibre 23.0 29.8 22.0 25.0 Crude carbohydrates 41.2 30.0 46.0 41.0 1 Raig 1980, 2 Regensburger 1954, 3 Salo et ai. 1982. 94 Fig. 6. DM yields of goat’s rue, red clover and lucerne at the Department of Plant Husbandry, Helsinki, Finland in 1979—1983 (Mäkäräinen et ai. 1985). Table 10. Composition of the Ist and 2nd cuts ofgoat’s rue (Jauho 1984). Ist cut 2nd cut (22. 6.) (16. 9.) Dry matter Ash 17.214.4 8.88.4 22.521.2 2.82.7 Crude protein Fat Crude fibre 18.5» 30.9 b Crude carbohydrates 47.3“ 35.9b 8.2.2 Digestibility and feeding value Goat’s rue keeps its feeding value very long, due to continuous development of new shoots. The stand is still green when the seeds of the main crop mature (Raig 1980). The stage of development affects the di- gestibility, as the proportion of indigestible stems and petioles increases with age. In Es- tonian trials, the ranges of the digestibilities of different components from shooting to full flowering were as follows (Raig 1980): Dry matter 66.7—53.3 % Carbohydrates 77.8—56.0 % Crude protein 85.9—63.0 °7o Fat 53.0—33.0 °7o Crude fibre 68.6—44.9 °7o Crude carbohydrates 83.7—60.7 % 8.2.3 Alkaloids The feeding value of goat’s rue is impaired by alkaloids. Three different alkaloid com- pounds have been isolated from goat’s rue: the guanidine derivatives galegine and 4-hydroxy- galegine, and the chiazoline-type ( + )-peganine (Schreiber et al. 1962) (Fig. 8). Table 11. Mineral contents (% DM) of goat’s rue and red clover (Venla) yields at different dates in 1981 (Mäkä- räinen et ai. 1985). Ist cutting dale G. orientalis % in DM T. pratense % in DM P K Ca Mg P K Ca Mg 5.6. 16.6. 8.7. 17.7. 0.413.52 0.190.15 0.303.36 0.370.16 0.342.85 0.480.15 0.363.90 1.160.25 0.293.71 0.850.20 0.263.42 0.760.19 Fig. 7. Relationship of the date of cutting with (a) the crude protein content (the average of 1981 and 1982) and (b) the crude fibre content (in 1981 only) for goat’s rue and red clover. The clover was cut some 10 days later than the goat’s rue (Mäkäräinen et ai. 1985). 95 96 Guanidine derivatives are poisonous in substantial amounts, and even when not poi- sonous, peganine causes a bitter taste. In the leaves of G. officinalis the contents of galegine and 4-hydroxy-galegine are 0.10—0.25 % of dry matter and that of peganine is 0.05— 0.1 % (Pufahl and Schreiber 1963). The alkaloid content of G. orientalis is lower and, according to German results, it does not con- tain galegine or 4-hydroxy-galegine (Schrei- ber et al. 1962). There is more variation in the peganine con- tent of different populations of G. officinalis than in the galegine and 4-hydroxy-galegine contents. The development stage affects the galegine and peganine contents differently. The galegine content is highest during flowering and lowest during seed maturation, whereas the peganine content decreases continuously as the plant ages. The age of the leaf affects the content of 4-hydroxy-galegine less than that of galegine, the trend decreasing with ageing of the leaves. Moisture, photoperiodism and temperature have almost no effect on the galegine content and their effect on other alkaloids is also small (Schäfer and Stein 1969). Similar analyses have not been carried out on G. orientalis. The effects of the alkaloids in G. officinalis and G. orientalis on animals were investigated in Germany at the end of the 1960’5. It was found that an alcoholic extract from leaves of flowering plants and seeds of G. officinalis caused symptoms of poisoning in rats, the leaf extract being more toxic than the seed extract. Small amounts caused depression and greater amounts spasms and paralysis. The lethal dose of galegine sulphate was 77.5 mg per kg of the animal’s weight. Peganine did not cause symptoms of poisoning, but is thought to be responsible for the bitter taste of goat’s rue. Seed or seed extracts of G. orientalis had no harmful effects (Köhler 1969). The possibility of reducing the amount of guanidine derivatives in goat’s rue by plant breeding seems to be remote, because they ap- pear to be regulated by several genes and the variation between individual plants is small (Richter 1968). The peganine content could be more easily changed by breeding, because there is more variation and more plants with no peganine may be found (Schäfer and Stein 1969). 9. Use as fodder 9.1 Silage Goat’s rue is well suited for both fresh and pre-wilted silage, when growing in pure stands or stands containing 20—25 % grass. As the protein content is high and the sugar content low, successful preservation is secured by using a preservative. According to Estonian results, six litres of preservative per ton of raw material is needed. The use of preservative Fig. 8. Alkaloids in goat’s rue (Schreiber et al. 1962). decreases ensiling losses by 35—55 °/o (Raig 1980, 1982). 9.1.1 Goat’s rue as silage material When the suitability of goat’s rue for silage was investigated at the Department of Animal Husbandry of the University of Helsinki in 1982, silage made from goat’s rue was found to fulfil the quality requirements set for good silage (Table 12). Table 12. Characteristics of goat’s rue silage in 1982 (Jauho 1984). First Second Recommended cutting cutting values Characteristic pH 3.87 3.90 3.7—4.0 % DM Lactic acid 2.69 2.17 0—1 —(2) Sugar 5.26 4.44 more than (I)—2 Acetic acid 0.87 1.17 no recomm. Propionic acid 0.04 + no recomm. Butyric acid less than 0.1 NHj-N 0.07 0.16 below 0.3 Soluble N 1.53 1.35 no recomm. % Total N 2.13 4.61 no recomm.NH,-N Soluble N 44.9 39.6 no recomm. The pH of the silages was optimal and the amount of lactic acid was acceptable. The sugar contents were high, especially in the first cut. The ammonium content, the measure of decomposition of CP, was higher in the second cut than in the first cut, but was satis- factory, as was the proportion of soluble nitrogen in total nitrogen. Acetic acid was rather high, but no butyric acid was found. Storage losses were higher in the first-cut silage (Table 13). Table 13. Storage losses of goat’s rue silages (Jauho 1984). Ist yield 2nd yield Effluent, % FWT 18.3 19.5 Effluent % DM 5.2 4.7 Fermentation % DM 2.0 1.5 Putrefaction % DM 12.1 0.4 Total DM loss 19.3 6.6 In silage making, most putrefaction losses usually take place in summer because of the high temperature. Usually, only soluble com- ponents, such as minerals and sugars, are lost in the effluent, but goat’s rue effluent also contained much protein (more than 25 % of effluent DM). The fermentation losses in the first cutting were due to crude protein (6.2 %) and crude carbohydrates (7.0 %). The major part of the fermentation losses in autumn were due to losses of crude carbohydrates. Putrefaction losses affected all components of the silage alike. Total losses were greatest in the proteins in both silages. From the first cutting, 23.6 % of the crude protein was lost, and from the second cutting 4.8 %. 9.1.2 Digestibility and feeding value of goat’s rue silage The feeding value of goal’s rue silage was investigated at the Department of Animal Husbandry in 1983 in vitro and in vivo (Jau- ho 1984). Four Texel rams were fed with silage made from the first and second cuttings of goat’s rue. The silage was made with “AIV II” preservative. The fodder rations were cal- culated to be equivalent to the maintenance requirement of the rams. In addition the animals were given minerals. The raw material from the second cut- ting was older and the silage less digestible (Table 14). The in vitro digestibility of the organic matter in the raw material of the first cut was 75.8 % and in the second cut 64.5 *7o. Silage making reduced the digestibility of the organic matter in the first-cut silage to 72.6 % and in the second-cut to 57.7 %. The in vivo digestibility was measured on the silage alone. All components of the silage were sig- nificantly more digestible in the first cutting than in the second. The fibre content and its digestibility was responsible for the lower values of the second-cut silage. The hard stems in the second-cut silage were not eaten by the animals, and were treated as excrements in cal- culating the digestibility. The nitrogen balance was positive in the silage from both cuttings, but significantly higher in the first-cut silage. 97 Table 14. Digestibility (%) and nitrogen balance of goat’s rue silage (Jauho 1984). Component Ist cut 2nd cut Dry matter 71.7 a 54.5 b Ash 56.9 a 43.6 b Organic matter 73.0 a 55.4 b Crude protein 77.5 a 68.3 b Fat 64.2 a 57.4 b Crude fibre 66.9 a 41.6 b Crude carbohydrates 79.7 a 59.2 b Nitrogen balance g 5.12 a 1.27 b The silage from the first cutting had the replacement value of 6.4 kg/fu (kg fodder/ feed unit, feed unit = 0.7 kg starch equiva- lent), which is approximately the same as for a good quality grass silage (Syrjälä and Ojala 1978). The replacement value for the second- cut silage was significantly higher (10.6 kg/fu), partly because of the low dry matter con- tent. The bulkiness in the first-cut silage was 1.3 kg/fu, whereas in the second-cut silage it was 1.7 kg/fu, because of the high fibre con- tent. The protein content was 211 g and 253 g of soluble crude protein/fu in the first-cut and second-cut silage, respectively. Silage with a high protein content can thus be made even from late cuttings of goat’s rue. 9.1.3 Palatability of goat’s rue silage The palatability of goat’s rue silage was in- vestigated at the Department ofAnimal Hus- bandry on December 13—26 in 1982 (Jauho 1984). The experiment lasted only ten days, and two Finnish rams were used. The silage was made from the second cutting. The ani- mals received enough silage for 10 % left over. Minerals and water were also given (Table 15). The daily voluntary intake was 9.53 kg. The intake was 64.4 g/kg metabolic live weight. Though this value is low, the animals gained weight during the experiment. The voluntary DM intake per kg live weight was 21.9 g. This figure is low compared with the intake values for timothy silage. The digestibility of this silage was low, 58.8 %, and the animals left the hard stems. Table 15. Palatability of goat’s rue silage. Second cut (Jauho 1984). Ram 1 Ram 2 x Voluntary intake of fresh silage g/d 1 0210 8 850 9 530 Voluntary intake of DM g/d 1 740 1 500 1 620 g/kd W°- 75/d 68.9 59.8 64.4 No evidence was observed that alkaloids low- ered the palatability of the silage. The protein content of goat’s rue silage is high, but it should be cut early enough to avoid a high fibre content and low digestibility of stalks and stems. 9.2 Fresh feeding and grazing Goat’s rue is considered to be 15—20 days earlier in development than red clover. Being high in protein content, a young goat’s rue stand has a replacement value that is sufficient for high-production dairy cows without any additional fodder (Raig 1980). However, the grazing tolerance of goat’s rue and its palat- ability for cows have not been investigated. 9.3 Hay Hay can also be made from goat’s rue. Goat’s rue hay has a replacement value of 1.6—1.8 kg/fu and a protein content of 156— 198 g soluble crude protein/fu (Jartijeva 1977). In Estonia, artificial drying is recom- mended to assure curing and to avoid shedding of leaves. The early harvest of goat’s rue can be considered an advantage in Finnish weather conditions. 9.4 Protein concentrate Protein concentrate can be made from goat’s rue. According to Estonian experiments, juice extracted from goat’s rue contains 12 °Io dry matter and 2.8 % crude protein. The protein is easy to precipitate and is suitable for feeding cows, calves, pigs and hens (Raig 1980). 98 The leaf protein of goat’s rue has also been investigated at the Department of Animal Husbandry in Helsinki (NAsi and Kiiskinen 1985). Juice was extracted from fresh leaves and filtered through gauze. The substance collected on the gauze contained 52 % crude protein. The in vitro digestibility of the leaf protein was 89.5 %, which is higher than in other legumes. 10. Seed production Fairly good seed yields have been obtained from goat’s rue in Estonia. There, goat’s rue matures in the beginning of August, at a suitable time for combine harvesting. The recommended row spacing in Estonia is 60— 90 cm. The number of flowers and seeds are highest with this row spacing and weeds can be controlled mechanically or with herbicides (Raig 1982). In Finland, the seed production of goat’s rue also seems to be reasonably successful. Only one year’s results are available, but the seed used in field trials has been harvested in several years from a seed production plot. The seed has been ready for harvesting in August and the yield has varied from 300 to 500 kg/ha. The seed weight has been 6—7 g/1000 seeds and germination 80—90 %. Spacing of 25 cm seems to be better than 12.5 cm. The leaves are usually green when the seed is mature, which allows spraying with diquat a few days before the harvest. 11. Summary Goat’s rue (Galega orientalis) is a perennial, unselected forage legume originating from regions with a Mediterranean climate. Research has mainly dealt with its general properties and its responses to management practices. The experience gained with goat’s rue in- dicates that it can compete successfully with red clover in the quantity and quality of the yield, if the management takes account of its special growth pattern. The main advantage compared with red clover is its perenniality. It spreads with underground stolons and grows best in light soils, evidently tolerating acid soil conditions fairly well. Of the alkaloids found in G. officinalis, only peganine has been detected in G. orientalis. The species has a specific Rhizobium strain, which is not related to those of the common temperate legumes. Goat’s rue is cross-pollinating, is a good honey plant and has fairly good seed production. The following recommendations can be made on the basis of the management trials carried out at the Department of Plant Hus- bandry of the University of Helsinki. Goat’s rue should be sown early in the spring, with a seeding rate of 30 kg/ha. A seed mixture with timothy is possible, with 60—80 % of goat’s rue. As the early growth is slow, goat’s rue is intolerant of cover crops and gives a low yield at the single cut in late September of the seeding year. In Finnish conditions, the num- ber of cuts in later years should be restricted to two, to ensure good yields and to guarantee the development of underground stolon buds. The first cut should be made during early flowering (second half of June), the second cut late in September. Mineral nitrogen is not necessary when the sward consists solely or predominantly of goat’s rue, but small amounts of nitrogen can be given to mixtures with grasses during the first two years. Goat’s rue gives good raw material for silage when cut at the proper times. It has a high pro- tein content, good digestibility and good pay- ability. The quality of the silage is somewhat impaired by the thick stems with their high fibre content and low digestibility. Mixtures of grass and goat’s rue have not yet been inves- tigated in feeding trials. Leaf protein produc- tion is also possible. The leaf extract has a high protein content and a very high digestibility. So far, no pests or diseases have been dis- covered. Normal legume herbicides can be used for weed control. Literature Hegi, G. 1924. Industrierte Flora von Mittel-Europa, Band IV 3. Teil, 1388 p. Munchen. 99 Jartijeva, Z.A. 1977. Kormovaja tsennost i nekotorye priemy vozdelyvanijakozljatnika vostotsnogo ( Gatega orienlalis Lam.) v uslovijah tsentralnyh rajonov net- sernozemnoj Zony RSFSR. Autoreferat, M. 1977. Jauho, M. 1984. Vuohenherne säilörehun raaka-aineena. Laudaturtyö, kotieläintieteen laitos. 66 p. Kansanen, P. 1983. Vuohenherne ja sen viljelytekniikka. Suomen Akatemian sopimustutkimuksen nro 383 lop- puraportti. p. 93—126. Helsinki. Komarov, V.L, 1963. Flora USSR: 303—304. Wies- baden-Wehen 432 p. Köhler, H. 1969. Die Priifung von Gatega-Arten auf ihren Gehalt an Giftsstoffen mit Hilfe biologischer Methoden. Biologisches Zentralblatt 88: 165—177. Lattu, P. 1983. Kasvutiheyden janiittojen vaikutus vuo- henherneen satoon. Pro gradu -työ, kasvinviljelytieteen laitos. 68 p. Lindström, K. 1984. Analysis of factors affecting in situ nitrogenase (C2 H 2) activity of Gatega orienlalis, Tri- folium pratenseand Medicago saliva in temperate con- ditions. Plant and Soil 79: 329—341. Lindström, K., Jarvis, 8.W., Lindström, P.E. & Patel, J.J. 1983. DNA homology, phage-typing, and cross- nodulation studies of rhizobia infecting Gatega species. Can. J. Microbiol. 29: 781—789. Lindström, K., Sarsa, M.-L., Polkunen, J. & Kansanen, P. 1985. Symbiotic nitrogen fixation on Rhizobium (Gatega) in acid soils, and survival in acid and cold stress. Plant and Soil 87: 293—302, Milne-Redhead, E. & Polhill, R.M. (Ed.) 1971. Flora of Tropical East Africa, Part 4: 505—1108. London. Mäkäräinen, E., Kansanen, P., Kortesmaa, T. & Varis, E. 1985. Rehuvuohenherneen viljelyominaisuudet ja käyttöarvo. Biologisen typensidonnan jaravinnetypen hyväksikäytön projekti. Suomen itsenäisyyden juhla- vuoden 1967 rahasto. Julkaisu 14, 72 p. Näsi, M. & Kiiskinen, T. 1985. Leaf protein from green pulse crops and nutritive value of legume protein con- centrales for poultry. J. Agric. Sci. Finl. 57: 117—123. Proctor, H. & Moustafa, E. 1962. Root nodules of Gatega officinalis. New Zealand J. Sei. 5: 184—190. Pufahl, K. & Schreiber, K. 1963. Zum diinnschicht- chromatographischen Nachweis von Inhaltstoffen der Geissraute, Gategaofficinalis. Ziichter 33: 287—290. Raig, H. 1980. Söödagaleegakasvatamme ja kasutamine. Tallinna, Valgus. 64 p. 1982. Experience with newly introduced fodder plant Gatega orienlalis Lam. in the Estonian S.S.R. Tallinn. 15 p. Regensburger, G. 1954. Ricerche sulia produttivita della capraggine (Gatega officinalis) sottoporta a coltivazione. (Research of the productivity of goat’s rue under cultivation), s. 512—514. Institute Sperimentale Zoo- tecnico, Roma. Richter, E. 1968. Untersuchungen und Vorschläge zur Auslese von alkaloidarmen Pflanzen der Galega-aiten durch chemische Massenselektion. Theor. Appi. Genetics 38: 118—122. Salo, M.-L., Tuori, M. & Kiiskinen, T. 1982. Rehutau- lukot ja ruokintanormit, 70 s. Helsinki. Schreiber, K., Aurich, O. & Pufahl, K. 1962. Isolierung von (+ )-Peganin in Geissraute, Gatega officinalis Lara. Archiv der Pharmazie 295: 271—275. Schafer, J. & Stein, M. 1969. Untersuchungen iiber toxische Inhaltsstoffe bei Gatega orienlalis L. Bio- logisches Zentralblatt 88: 755—768. Syrjälä, L. & Ojala, R, 1978. Kevät- ja syyssadosta eri kehitysasteilla valmistetun timoteisäilörehun ravinto- arvo. Kehittyvä Maatalous 39: 36—49. Tutin, T.G., Heywood, V.H., Burges, N.A. et al. 1968. Flora Europaea. Vol 2: 107. Cambridge 454 p. Willis, J.C. 1973. A Dictionary of the Flowering Plants and Ferns. 8 ed. Cambridge 1245 p. Ms received September 8, 1986 100 YHTEENVETO Rehuvuohenherne (Galega orienlalis Lam.), mahdollinen monivuotinen lauhkean vyöhykkeen rehukasvi Eero Varis Helsingin yliopisto. Kasvinviljelytieteen laitos 00710 Helsinki Rehuvuohenherne (Galega orienlalis Lam.) on Väli- meren ilmastoalueelta peräisin oleva monivuotinen, ja- lostamaton rehukasvi. Sen yleisiä viljelyominaisuuksia ja myös viljelytekniikkaa on tutkittu. Saatujen tulosten ja kokemusten pohjalta voidaan sanoa sen menestyksellisesti kilpailevan puna-apilan kanssa sekä sadon määrän että laadun suhteen, kunhan sitä viljellään sen oman kasvu- ja kehitysrytmin mukaisesti. Sen suurin etu puna-apilaan verrattuna on sen pitkäikäisyys. Se leviää maanalaisin rön- syin ja viihtyy parhaiten keveillä mailla. Se näyttää kes- tävän maan happamuuttamelko hyvin, Rohtovuohenher- neestä (G. officinalis, L.) tavatuista alkaloideista rehu- vuohenherneestä onlöydetty vain peganiinia. Vuohenher- neellä on oma Rhizobium- kantansa, joka ei ole sukua muille lauhkean ilmaston ritsobeille. Se on ristisiittoinen laji, hyvä hunajakasvi ja siemenen saanti on suhteellisen helppoa. Tässä raportissa selostetaan Helsingin yliopiston kas- vinviljelytieteen laitoksella suoritettuja vuohenherneen vil- jelyteknillisiä kokeita. Kevätkylvö 30 kg:n siemenmäärää käyttäen näyttää suositeltavalta kylvötavalta. Siemenseos timotein kanssa, jossa on 60—80 % vuohenhernettä, näyt- tää mahdolliselta. Vuohenherne kehittyy kylvövuonna hi- taasti, ja ilmankin suojaviljaa, mitä se ei näytä sietävän, se tuottaa kylvövuonna vain yhden vaatimattoman sadon syyskuun lopulla. Suomen kasvuoloissa kaksi niittoa seu- raavina vuosina näyttää riittävältä runsaan, hyvälaatui- sen sadon saamiseksi ja maanalaisten rönsyjen kasvusil- mujen kehityksen turvaamiseksi. Ensimmäinen niitto suositellaan kukinnan alkuvaihees- sa kesäkuun loppupuoliskolla, toinen niitto syyskuun lop- pupuolella. Typpilannoitus ei ole tarpeen puhtaalle tai vuohenhernevaltaiselle nurmelle, lukuunottamatta seos- nurmea parina ensimmäisenä vuotena, jolloin pieni määrä typpeä piristää timotein kasvua. Vuohenherneestä saadaan sopivia niittoaikojakäyttäen hyvää säilörehun raaka-ainetta. Sillä on korkea valkuais- pitoisuus, hyvä sulavuus jamyös hyvä maittavuus. Pak- sut varret ja niiden korkea kuitupitoisuus heikentävät jon- kin verran rehun laatua. Seosnurmien laatua ei ole tes- tattu ruokintakokein. Lehtiproteiinin valmistus vuohen- herneestä on myös mahdollista. Lehtiuutteen valkuaispi- toisuus ja sen sulavuus ovat hyvin korkeat. Muuta rehu- käyttöä ei ole tutkittu. Tähän mennessä vuohenherneestä ei ole tavattu taute- ja eikä tuholaisia. Se kestää samojaherbisidejä kuin muut- kin palkokasvit. 101 ERRATA: Varis, E. 1986. Goat’s rue (Galega orientalis, Lam.), a potential pasture legume for temperature conditions. Vol. 58: 83—101, 1986. Table 7. Total DM yield (kg/ha) from goat’s rue leys in 1983—85. Cutting time in the summer Cutting time in 4.6. 11.6. 19.6. 28.6. X the autumn 24.8. 12 510 17 030 15 360 14 830 16 170 16 710 18 900 18 510 14 560 21 400 20 360 20 190 16 250 22 660 22 080 20 830 14 860 a 19 450 b 19 180 b 18 570 b 7.9. 16.9. 5.10. X 14 930 17 570 19 110 20 450 18 020 ab ab ba F-value Summer cut ** HSD 0.01 =4 570 KG Autumn cut *** HSD 0.001 = 1 690 KG