Nitrogen, sulphur and other mineral elements in white clover and perennial ryegrass grown in mixed swards, with and without fertiliser N, at a range of sites in the UK

Abstract

Perennial ryegrass (Lolium perenne L. cv. S23) and white clover (Trifolium repens L. cv. Blanca) were grown in mixed swards, with and without fertiliser N as ammonium nitrate, at 12 sites in the UK. Grass and clover separated from herbage harvested in May, July and September, have been examined for N, S and other major mineral elements, in reIation to the nutrition of both the crop and ruminant animals. The total N content was greater in the clover than in ryegrass at each site, both with and without fertiliser N. The S content of the clover was similar to that of ryegrass at the first harvest in May, but was lower in July and September. There were large differences between the species in the ratio N:S, the average being 17.1 :1 in white clover and 8.6:l in ryegrass. The proportions of the total S present as sulphate were higher in ryegrass, with a mean of 48 %, than in the clover, with a mean of 16%. The contents of Mg, and particularly of Ca, were higher in clover, while K was generally higher in ryegrass. Consequently, the ratio K: (Ca+Mg) was always at least twice as high in the ryegrass as in the clover. In some of the ryegrass, but none of the clover samples, it exceeded 2.2:l. the value above which there is an increasing risk of hypomagnesaemia in ruminant animals. The content of total cations (Ca+ Mg+ K + Na) was on average 37% greater in the clover than in the ryegrass, while the content of total inorganic anions (but including organic P) was much less in the clover. The content of organic anions, as calculated from the difference between the contents of total cations and inorganic anions, was at least twice as great in white clover as in ryegrass.

Response of permanent and reseeded grassland to fertilizer nitrogen. 2. Effects on concentrations of Ca, Mg, K, Na, S, P, Mn, Zn, Cu, Co and Mo in herbage at a range of sites

“…These results are consistent with those of Reith et al (1964) and Whitehead et al (1978), who also found that the effect of fertilizer N outweighed that of KCl. The finding that the higher S concentrations occurred on the No plot at harvest 4 is consistent with results of McLaren (1976) and Whitehead et al (1983).…”

“…Increases in Na and Mn between spring and summer were reported by Hemingway (1961;1962) and Metson et al (1979), and a higher concentration of S in later cut herbage was noted by McLaren (1976). However, other previous studies have shown little evidence of consistent patterns of seasonal variation with regard to concentrations of Na (Metson and Saunders, 1978;Whitehead etal, 1983), Zn (Reay and Marsh, 1976;Metson et al, 1979) or total S (Whitehead et al, 1983). …”

Semi‐natural grassland biomass for combustion: influence of botanical composition, harvest date and site conditions on fuel composition

“…, 1952; Wöhlbier and Kirchgeßner, 1957; Forbes and Gelman, 1981), in the case of legumes higher, lower or equal K concentrations, compared to grasses, have been observed (Thomas et al. , 1952; Wöhlbier and Kirchgeßner, 1957; Forbes and Gelman, 1981; Whitehead et al. , 1983; Chiy and Phillips, 1996).…”

Robustness in the mineral supply from temporary grasslands

“…However, many pasture plants supply other elements that influence the performance of those ingesting the herbage. Belesky et al (2001) investigated mineral composition in pure stand chicory and Whitehead et al (1978) in pure stand ryegrass but studies in mixtures have also been reported (Whitehead et al, 1983, Lawes & Gilbert, 1990, Hopkins et al, 1994. Hopkins et al (1994) described the variation in selected macro-and micro-mineral concentrations in Lolium perenne/Trifolium repens-dominated swards over seasons and over years (Hopkins et al, 1994).…”