Crops
Melilotus officinalis (L.) Pall. - Yellow sweetclover, yellow melilot.
Taxonomic position.
Family Leguminosae Endl., genus Melilotus Mill.Morphology and biology.
2n=2x=16. Erect or ascending biennial herb, up to 1.5 m, with trifoliate leaves. Leaflets obovate, dentate in upper third and with terminal leaflet on longer petiole than lateral leaflets. Single well-branched stem in establishment year but in following years, several stems originate from crown buds. The succulent stems become fibrous with age. Deeply tap-rooted. Considerable root enlargement, and development of short rhizomes initiated from the plant crown, occurs in the autumn of the establishment year. Inflorescences are elongated one-sided racemes of yellow flowers, 4-5 mm, borne on long axillary stalks. Indeterminate flowering. Blossoms June-September, seed ripens July-October. Seed pod has a reticulated, ridged coat which turns black with ripening and contains a single or pair of smooth, kidney-shaped seeds, approximately 2 mm long, and brownish-yellow to brown in color. The weight of 1000 pods is 2.3 to 2.4 g. Cross- pollinated mainly by honey bees.Distribution.
Cultivated since the 19th century on relatively large tracts of land in the forest and steppe areas in 29 regions and republics of the former USSR. State permission for utilization has been given to 8 cultivars.Ecology.
Plants is winter hardy and productive, especially on fertile, well-drained clay and clay-loam soils. It can also be grown successfully on sandy loams and heavy, clay loams. It grows best on neutral or alkaline soils, and is one of the best legumes to grow on highly-alkaline soils. Yellow sweet clover can also be used in the revegetation of mechanically-disturbed lands, but it should not be planted on land that is subject to flooding or on acid soils. Like alfalfa, it is very sensitive to acid soils, and growth is severely limited below about pH 6.0. Although it tolerates a few days of flooding before growth begins in spring, it cannot endure flooding during the growing season. Like alfalfa, it is intolerant of waterlogged soil or poor soil drainage.Utilization and economic value.
As compared to white-flowered Melilotus albus, the yellow-flowered is finer stemmed, matures earlier, and is more drought-tolerant. It has a high nutritive value at the vegetative stage of growth when grazed, at the pre-flowering stage for silage, and at the early-flowering stage for hay. Compared with red clover, yellow sweet clover has a lower N content and higher cell wall and lignin content in the stems but higher N contents in the leaves. The high coumarin content of sweet clover makes it less palatable to livestock than many other legumes. However, low-coumarin varieties are now available. Bloat can be a problem when grazing sweet clover, although it is less common than with alfalfa or true clovers. Scouring may also occur, especially when growth is young and succulent. If the animals have access to dry roughage, both conditions will be reduced. Sweet clover is one of the best legumes for soil improvement. The widely-branched, deeply-penetrating tap roots open up the subsoil. The roots use nutrients not available to plants with shallow roots. When sweet clover plants decay, the nutrients in the roots are released for use by other crops. Forage mass productivity ranges from 6-24 MT/ha, hay productivity ranges from 2.0-9.0 MT/ha and seed productivity is 300-400 kg/ha. Sweet clover is an excellent source of nectar and pollen for honey bees.Reference citations:
Catalog of agricultural crop cultivars permitted in Byelorussia. 1985. - Minsk: Uradjai, 176 pp. (in Russian).Catalog of state permitted cultivars of agricultural crops. 1969. - Moscow: Kolos, 489 pp. (in Russian).
Catalog of state permitted cultivars of agricultural crops. 1971. - Moscow: Kolos, 488 pp. (in Russian).
Catalog of state permitted cultivars of agricultural crops. 1974. - Moscow: Kolos, 480 pp. (in Russian).
Catalog of state permitted cultivars of agricultural crops. 1985. - Moscow: Kolos, V. 3: 489. (in Russian).
Golovkin B.N. 1988. Cultigenic plant area. Moscow: Nauka. 184 pp. (in Russian).
Kashtanov A.N., ed. 1983. The Natural-agricultural regions and utilization of soil resources of the USSR. Moscow: Kolos. 336 pp. (in Russian).
Medvedev P.F., Smetannikova A.I. 1981. The forage crops of European part of the USSR. Leningrad: Kolos. 336 pp. (in Russian).
Shashko D.N. 1967. Agroclimatic region of the USSR. Moscow: Kolos. 335 pp. (in Russian).
Shashko D.N. 1985. Agroclimatic resources of the USSR. 1985. Moscow: Kolos. 248 pp. (in Russian).
Soil resources of the USSR (Agricultural regions of areas and republics of USSR). 1990. Moscow. V. 1: 26. (in Russian).
State register of breeding achievements permitted for utilization. Plant cultivars. 1994. -Moscow: -218 pp. (in Russian).
State register of breeding achievements permitted for utilization. Plant cultivars. 1996. -Moscow: -171 pp. (in Russian).
State register of breeding achievements permitted for utilization. Plant cultivars. 1999. -Moscow: -192 pp. (in Russian).
State register of breeding achievements permitted for utilization. Plant cultivars. 2000. - Moscow: -232 pp. (in Russian).
State register of breeding achievements permitted for utilization. Plant cultivars. 2001. -Moscow: -252 pp. (in Russian).
State register of breeding achievements permitted for utilization. Plant cultivars. 2003. -Moscow: -236 pp. (in Russian).
State register of Ukrainian plant cultivars. 1992. -Kiev: Urojai, 199 pp. (in Russian).
The register of plant cultivars in Ukraine. 1996. - Kiev: Urojai, 259 pp. (in Russian).