Goat's Rue

Economic importance

Goat's rue is a promising crop that can be used for meadow and field grass cultivation, for example, in out-of-rotation fields or for grassing over slopes. It has forage value and is used as green fodder, for preparing hay, haylage, and silage. It can also be used for ornamental purposes. In amino acid content it does not differ from alfalfa.

It is a honey plant, not inferior to sainfoin.

After goat's rue, a large amount of root and plant residues remains, more than after alfalfa or clover.

In the green conveyor system, this crop provides the earliest and the latest forage. In the rate of green matter formation in early spring, it surpasses other leguminous grasses; mowing can begin 15–20 days earlier in spring than for clover or alfalfa.

The fodder value of green matter remains high throughout the growing season. Two cuts are considered optimal for it, since constant three-cut mowing leads to reduced winter hardiness and thinning of stands. Regrowth after mowing is good.

100 kg of goat's rue hay contains 56.3 feed units and 16.8 kg of digestible protein (VNII of Feeds). Dry matter content in green matter is 20–25%. 100 kg of green matter contains on average 24 feed units, and grass meal 75 feed units. Per 1 feed unit, green grass contains 135 g of digestible protein, hay 190 g, and grass meal 198 g. Green matter contains a large amount of ascorbic acid, carotene, flavonols, and minerals. It also contains active substances that stimulate milk secretion in animals.

Due to its well-developed root system, it is promising for grassing over eroded soils.

The period of use is 7–15 years.

History of cultivation

In Russia it was introduced into cultivation at the end of the 19th century.

It has a southern origin — endemic to the North Caucasus.

Yield

Hay yield can reach 7–10 t/ha, green matter 30–80 t/ha, and seed 200–800 kg/ha.

Botanical description

Eight species of goat's rue are known, growing in Europe and Asia. In Russia, the species of practical use is eastern goat's rue, or eastern galega, or rutovka — Galega orientalis Lam. It belongs to the legume family.

Eastern goat's rue is a long-lived plant; in natural plant communities it reaches a height of 50–80 cm, and under cultivation 130–200 cm.

The root is taprooted, powerful, with numerous lateral branches and a developed network of thread-like rootlets; it penetrates the soil to 50–80 cm. On the main root at a depth of up to 7 cm, 2–18 rhizomatous offshoots are formed, which grow horizontally to a distance of up to 30 cm. Then the offshoots emerge to the soil surface and form a stem.

Due to its ability for vegetative propagation, the goat's rue stand does not thin out over time but becomes denser.

On the underground part of the stems, 3–4 overwintering buds are formed each year; together with root offshoots, these enable the plants to resume growth.

The stem is erect, hollow, branching, leafy, up to 80–150 cm tall. One bush consists of 10–18 stems.

The leaves are large, compound, odd-pinnate, with 5–6 pairs of leaflets. In hay, leaves account for up to 75–80%. When drying, the leaves do not shatter.

The inflorescence is a many-flowered, erect, elongated raceme. The flowers are large, blue-violet, white-blue, or white, 25–75 per raceme, typical of the legume family, but open with shallow nectaries. The flower structure promotes better seed set.

The fruit is a linear or slightly curved pod, brown, light or dark brown, and does not dehisce at maturity. The seeds are large, elongated-reniform, yellowish-green or olive at harvest, and acquire a light brown color during storage. The 1000-seed weight is 5.5–9.0 g.

Biological characteristics

Eastern goat's rue is characterized by good cold resistance, frost resistance, and drought resistance.

In winters with little snow, it can tolerate frosts down to -25 °C; with good snow cover, down to -40 °C. In spring it may suffer frost damage, but quickly restores its stems. Autumn and spring frosts down to -5…-7 °C cause no damage.

It can withstand flooding for up to 18 days; complete death of plants occurs after 25–30 days. In water requirement, it occupies an intermediate position between clover and alfalfa.

It is a light-demanding crop and tolerates shading poorly.

Chernozem sandy loam and light loamy, moist, non-waterlogged soils are optimal. It grows well on drained lowland peat bogs and floodplain lands. Soil reaction is close to neutral. Poor soils are poorly suitable. It belongs to plants that respond little to liming and is resistant to increased soil acidity.

Plant nutrition

From 1 t of green matter, 5.5 kg of nitrogen, 8 kg of phosphorus, 32 kg of potassium, and 10 kg of calcium are removed from the soil.

Growing season

In the sowing year, eastern goat's rue develops slowly, producing only one cut; plant height reaches 60–70 cm. In the sowing year it may flower in autumn if sown early. For reliable overwintering, first-year plants need at least 100–120 days of active growth.

From the 2nd–3rd year of use, it begins to regrow early and intensively, suppressing weeds well, except couch grass. In the Non-Chernozem zone, flowering occurs in early June.

Development type: spring.

Cultivation technology

Predecessors in crop rotation, soil tillage, and fertilizers for goat's rue are similar to the cultivation technologies recommended for other perennial leguminous grasses.

It is usually placed on out-of-rotation plots. The best predecessors are considered to be row crops; cereals and annual grasses are also suitable.

Fall plowing is carried out to the depth of the arable soil layer. Before plowing, 80–90 t/ha of manure and phosphorus-potassium fertilizers P_90-120K_90-120 are applied. Nitrogen fertilizers are usually not applied, since goat's rue is capable of nitrogen fixation. If necessary, N₆₀ can be applied in spring before pre-sowing cultivation.

In spring, harrowing and pre-sowing cultivation are carried out with combined implements RVK-3.

Sowing

The optimal sowing time is in spring without a cover crop or under a cover crop with a 30–50% reduction in the cover crop seeding rate, since goat's rue tolerates shading poorly. For the Non-Chernozem zone, the optimal time is the first half of May.

The sowing method depends on the type of use and weed infestation of the fields. When grown for forage on weed-free plots, the sowing method is row. With heavy weed infestation and without herbicides, wide-row sowing with 45 cm row spacing is recommended to allow subsequent cultivation as for row crops. When growing goat's rue for seed purposes, row spacing is 60 cm.

The seeding rate in pure stand is 20 kg/ha; in mixtures with grasses, 14–16 kg/ha. The seeding rate for row sowing is 30–40 kg/ha; for wide-row sowing, 10–20 kg/ha. Sowing depth is 1.5–2.0 cm.

Hard seed content is 50–98%, so scarification is carried out before sowing, for example using clover scarifiers. It is also recommended to treat seeds with bacterial preparations, for example Rhizotorfin (nitragin); there should be at least 40,000 bacteria per seed.

Plant care

According to research by the VNII of Feeds and the Timiryazev Moscow Agricultural Academy, to control weeds in first-year goat's rue stands, Eradican or Treflan can be applied before sowing, followed by treatment of the stands with a mixture of 2,4-DM and Basagran.

Starting from the second year of life, plant care in goat's rue reduces to cultivation and application of phosphorus-potassium fertilizers.

Harvesting

Harvesting for hay, haylage, or silage begins at the flowering stage. Unlike other leguminous grasses, leaves do not shatter during haymaking. Harvesting for grass meal is carried out at the stem elongation and budding stages. The aftermath can be mowed in September–October.

In the conditions of the Non-Chernozem zone, the highest productivity is ensured by two cuts.

Growing for seed

To control pests (flea beetles, nodule weevils, etc.) in seed stands, preparations recommended for alfalfa are used, for example Karate, Lambda, Altyn, Gladiator, Actellic.

Goat's rue allows obtaining stable seed yields; the seeds do not shatter when the fruits ripen. Harvesting for seed begins when 75–80% of pods turn brown, i.e. in late July–early August.

A feature of seed growing is that when harvesting seeds by direct combining at a high cut, the remaining stubble can be used for forage purposes (hay, haylage, silage), since most leaves and stems remain green.

Varieties

Gale. The variety was developed by the Kaluga Research Institute of Agriculture in 1988.

Gorno-Altaysky 87. Developed by the Altai Research Institute of Agriculture in 1992.

VNIIOK 1 (1994).

Yalginsky. Developed by the Chuvash Research Institute of Agriculture in 1994.

Yelya-ty. Developed by the Institute of Biology, Komi Scientific Center, Ural Branch of the Russian Academy of Sciences, in 1998.

Nadezhda. Developed by CJSC Russian Seeds in 1998.

Magistr. Developed by the Penza Research Institute of Agriculture in 2000.

Tyumensky. Developed by the Research Institute of Agriculture of the Northern Trans-Urals in 2001.

References

1. Vavilov P. P., Gritsenko V. V., Kuznetsov V. S. et al. (1986). Crop Production. Edited by Vavilov P. P. 5th ed., revised and expanded. Moscow: Agropromizdat.
2. Kolomeichenko V. V. (2007). Crop Production/Textbook. Moscow: Agrobiznescentr.
3. Niklyaev V. S. (2000). Fundamentals of Agricultural Production Technology. Agriculture and Crop Production. Moscow: Bylina.
4. S_15