Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-20T05:15:59.428Z Has data issue: false hasContentIssue false

The nutrient requirements of herbage on deep acid peat

Published online by Cambridge University Press:  27 March 2009

J. W. S. Reith
Affiliation:
The Macaulay Institute for Soil Research, Graigiebtickler, Aberdeen
R. A. Robertson
Affiliation:
The Macaulay Institute for Soil Research, Graigiebtickler, Aberdeen
R. H. E. Inkson
Affiliation:
The Macaulay Institute for Soil Research, Graigiebtickler, Aberdeen

Summary

A mixed sward of grasses and clovers, previously established with adequate Ca, N, P and K on deep acid peat, was used for a factorial experiment to determine the amounts of nutrients required to produce herbage for conservation. The treatments consisted of all combinations of 0, 117and 234 kg N, 0, 29 and 58 kg P and 0, 156 and 312 kg K/ha, and their effects on the botanical composition of the sward, the yield and mineral composition of the herbage, and the nutrient status of the peat were measured over a period of five years. Three cuts were taken annually, one third of the N dressings being applied for each cut.

Tall fescue became the dominant grass species while cocksfoot persisted much better than either ryegrass or timothy. The proportion of clover in the sward was reduced to practically zero by applying N, but without N it was maintained at about 20% by applying K.

Yields of dry matter were greatly increased both by N and by K and there was a marked positive interaction between these two nutrients. Due to the marked suppression of clover by applied N there was no response to the first increment of N in 1959, but with this exception, 1 kg N/ha with adequate P and K produced between 15 and 30 kg dry matter/ha. The effect of K increased from 1958 to 1962, the first increment consistently producing most of the response. Applying P had little effect on yield until the fifth year when a significant response was obtained.

The mineral composition of the herbage varied during the season; the percentages of N, Ca, Na and Mg were generally higher in autumn than in early summer whereas the percentage of K showed the opposite effect.

The N, P and K treatments had large effects on the percentages of N, P, K, Na, Ca and Mg in the herbage and on the amounts removed in the crop. Without applied N, but with adequate P and K, percentage of N varied according to the amount of clover in the sward. With applied N there was less variation and the average percentage of N was about 1·7 with 39 kg N and 2·0 with 78 kg N/ha/cut. Percentage of P ranged from 0·14 to 0·54 and percentage of K from 0·5 to 3·5. Apparent recoveries up to 74, 65 and 96 % were obtained from the N, P and K treatments, respectively.

For continuous production by cutting and removing the herbage, a mixed sward containing clovers appears to require, without applied N, about 120 kg K/ha/year. With applied N, an additional 0·3 to 0·5 kg K/kg N appears to be needed. The amount of P required will depend mainly on the concentration desired in the herbage and on the rate of N used. To produce herbage with 0·3 % P in the dry matter about 15 kg P/ha/year, plus approximately 0·1 kg P/kg N applied seems to be needed; for 0·4 %P the corresponding quantities are about 40 kg P/ha plus 0·3 kg P/kg N applied.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1973

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Castle, M. E. & Holmes, W. (1960). The intensive production of herbage for crop-drying. VII. The effect of further continued massive applications of nitrogen with and without phosphate and potash on the yield of grassland herbage. J. agric. Sci., Camb. 55, 251–60.CrossRefGoogle Scholar
Heddle, B. G. (1967). Long-term effects of fertilizers on herbage production. I. Yields and botanical composition. J. agric. Sci., Camb. 69, 425–31.CrossRefGoogle Scholar
Heddle, R. G. & Crooks, P. (1967). Long-term effects of fertilizers on herbage production. II. Chemical composition. J. agric. Sci., Camb. 69, 433—41.CrossRefGoogle Scholar
Heddle, R. G. & Simpson, K. (1969). Long-term effects of fertilizers on grassland. III. Effects on some soil properties. J. agric. Sci., Camb. 73, 4955.CrossRefGoogle Scholar
Hemingway, R. G. (1963). Soil and herbage potassium levels in relation to yield. J. Sci. Fd Agric. 14, 188–95.CrossRefGoogle Scholar
Ogg, W. G., Garst, J. & Macleod, A. (1931). Reclamation and cultivation of peat land in Lewis. Part II. Scott. J. Agric. 14, 131–40.Google Scholar
Ogg, W. G. & Robertson, I. M. (1934). The reclamation of moorland. Emp. J. exp. Agric. 2, 163–73.Google Scholar
Ogg, W. G. & Robertson, I. M. (1940). The reclamation of moorland. Part II. Reclamation experiments in Scotland. Emp. J. exp. Agric. 8, 5664.Google Scholar
Reith, J. W. S., Inkson, R. H. E., Stewart, A. B., Holmes, W., Maclusky, D. S., Reid, D., Heddle, R. G., Clouston, D. & Copeman, G. J. F. (1961). The effects of fertilizers on herbage production. I. The effect of nitrogen, phosphate and potash on yield. J. agric. Sci., Camb. 56, 1729.CrossRefGoogle Scholar
Reith, J. W. S., Inkson, R. H. E., Holmes, W., Maclusky, D. S., Reid, D., Heddle, R. G. & Copeman, G. J. P. (1964). The effects of fertilizers on herbage production. II. The effect of nitrogen, phosphorus and potassium on botanical and chemical composition. J. agric. Sci., Camb. 63, 209–19.CrossRefGoogle Scholar
Reith, J. W. S. & Robertson, R. A. (1971). Lime and fertilizer requirements for the establishment and growth of grass on deep peat. J. agric. Sci., Camb. 76, 8995.CrossRefGoogle Scholar
Surveys, Scottish Peat (1965). Department of Agriculture and Fisheries for Scotland, 3, Central Scotland, pp. 6991. Edinburgh: H.M.S.O.Google Scholar
Stewart, A. B. & Holmes, W. (1953). Manuring of grassland. I. Some effects of heavy dressings of nitrogen on the mineral composition of grassland herbage. J. Sci. Fd Agric. 4, 401–8.CrossRefGoogle Scholar
Wolton, K. M. (1963). Fertilizers and hypomagnesaemia. N.A.A.S. q. Rev. 14, No. 59, 122–30.Google Scholar