White clover

CLOVER, red (Trifolium pratense L.) CLOVER, white (T. repens L.)... 

CLOVER, white sweet (MtHlotus alba Desr.) COLEUS (Coleus blumei Benth.)... 

From an agricultural viewpoint. Piper and Pieters classify leguminous green manure crops as (1) summer annuals, chiefly soybeans, cowpeas, peanuts, beans, velvet beans, common vetch and field peas (2) winter annuals, including hairy vetch, common vetch, crimson clover, bur clover, field peas and red clover (in the south) and (3) biennials or perennials, comprising red clover, alsike clover, white clover, alfalfa and sweet clover. Each of these crops is adapted more or less definitely to a limited region. 

As with selenocystine, the amino acid selenomethionine, CH3Se(CH2)2CH(NH2)COOH, is largely incorporated into proteins but has been found in the free form to some extent. Onions Allium cepa) which had been injected with radioactive selenite were reported to contain selenomethionine as were ethanol extracts of red clover, white clover and rye... 

Perennial ryegrass Cocksfoot Red clover White dover Pasture... 

Stein-kem, m. stone (in fruit, in burnt lime), -kitt, m. cement for stone, -klee, m. melilot (Melilotua, esp. M. officinalia) white clover (Trifolium repena). -kohle, /. mineral coal, coal. 

Weiss-kies, m. arsenopyrite. -klee, m. white clover. 

Further confirmation that the HCN polymorphism is a general phenomenon came from the work of a colleague at the University of British Columbia, Fred Ganders (1990), who studied white clover from six sites in southwestern British Columbia and adjacent Washington. In all but one of the sites (the exception being a particularly... 

Dawson, C. D. R. 1941. Tetrasomic inheritance in Lotus corniculatus L. J. Genetics 42 49-72. de Araujo, A. M. 1976. The relationship between altitude and cyanogenesis in white clover (Trifolium repens L.). Heredity 37 291-293. 

Ganders, F. R. 1990. Altitudinal dines for cyanogenesis in introduced populations of white clover near Vancouver, Canada. Heredity 64 387-390. 

Saucy, F., Studer, J., Aerni, V. and Schneiter, B. 1999. Preference for acyanogenic white clover Trifolium repens) in the vole Arvicola terrestris I. experiments with two varieties. J. Chem. Ecol. 25 1441-1454. 

Data on safety have been obtained from in vitro as well as in vivo animal and human studies (see also Section 10.4). About 50 years ago, Australian farmers observed an infertility syndrome in sheep associated with the consumption of clover species (Bennets et al., 1946). The clover compounds shown to cause the infertility (genistein, daidzein, equol, biochanin A, formononetin) were members of the isoflavone family (Bradbury and White, 1951 Shutt and Braden, 1968), raising the question of whether soy might cause infertility in humans (see also Section 10.4.9). A variety of reports further supported adverse effects of isoflavones on animal reproductive systems (Santell et al., 1997 Flynn et al., 2000a,b). 

BRADBURY RB and WHITE D E (1951) The chemistry of subterranean clover. Parti. Isolation of formononetin and genistein. J Chem Soc. 12 3447-9. 

BCR CRM 402 Trace Elements in White Clover 0, = 0.456 at 2i.r°C w.c. = 7.52 0.04%. Despite its relatively high value, the water activity is still in the range for long-term stability and major differences in the water content as a consequence of sorption processes are not to be expected. This is supported by the fact that no spoilage has been observed, even though the production was in 1987. 

X. L. Li. E. George, and H. Marschner, Extension of the phosphorus depletion zone in VA-mycorrhizal white clover in calcareous. soil. Plant and Soil I3I 4 (1991). X. L. Li, E. George, and H. Marschner, Acquisition of phosphorus and copper by VA-mycorrhizal hyphac and root-to-shoot transport in white clover. Plant and Soil 135 49 (1991). 

S. U. Saratchandra, G. Burch, and N. R. Cox, Growth patterns of bacterial communities in the rhizoplane and rhizosphere of white clover (Trifolium repens L.) and... 

U. Schenk, R. Manderschied, J. Hugen, and H.-J. Weigel, Effects of CO, enrichment and intraspecific competition on biomass partitioning, nitrogen content and microbial biomass carbon in soil of perennial ryegrass and white clover, J. Exp. Bot. 46 987 (1995). 

Soil pH is easily tested for and determines the availability of nutrients and the success of white clover. Very acid soils (below pH 5.0) will cause a deficiency of the trace elements iron, boron, copper and molybdenum and conversely will cause injury to plant growth by increasing the availability of aluminium and manganese to toxic levels. Over-liming, on the other hand, which can raise the pH above 6.5, will reduce the availability of certain essential elements such as phosphorus, manganese and boron. 

Forage legumes, of which white clover is the most important, are particularly sensitive to calcium deficiency and will not thrive. Ideally, soil pH should be maintained between 5.8 and 6.5. Heavy-textured soils such as clay require more lime than sandy soils to raise pH, because the higher levels of clay and organic matter act as a buffer against change, and the same is true of peaty soils. 

In a comparison of the yield and nitrogen fixing ability of white clover, red clover and lucerne, Loges, et al. (2000) found higher yields of harvestable dry matter and therefore of nitrogen fixation for red clover and lucerne than for white clover, but white clover, of course, is a perennial. 

The problem in predicting the yield characteristics of a grass/white clover sward is that the relationship between yield and proportion of white clover in the sward is not linear. Grass/white clover swards yield more dry matter than either grass or white clover swards on their own, but the point where increasing the amount of white clover in the sward actually decreases total yield has not been defined experimentally. 

In Denmark, Hogh-Jensen (2000) studied the effect of white clover on the nutritional content of the companion perennial ryegrass and found that white clover increased the K and P content in the ryegrass. 

Curll, ci al. (1985) measured an increase in total yield from 6 t dry matter per ha with 10% white clover in the dry matter up to 11 t dry matter per ha with 45% white clover (Fig. 2.4). The increase in total yield was mainly caused by the increase in clover yield the grass yield remained more or less static, with clover levels above 20%. Reports from other experiments show considerable variation in the response. For this reason it can be stated only that white clover increases total herbage yield, but not at very high levels of clover, and that white clover always improves milk yield and liveweight gain compared with grass alone. 

Fig. 2.4 The effect of proportion of white clover on total herbage yield.

Curll, M.L., Wilkins, R.J., Snaydon, R.W. Shanmugalingham, V.S. (1985) The effects of stocking rate and nitrogen fertilizer on a perennial ryegrass -white clover sward. Grass and Forage Science, 40, 129-40. 

Adequate levels of lime, phosphate and potash in the soil are especially important for organic dairy farmers, because these nutrients are essential for healthy white clover. The supply of these nutrients and general manure strategy is covered fully by Newton (1993). 

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