Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-25T05:43:42.258Z Has data issue: false hasContentIssue false

The effects of rates of potassium application on the production arid quality of herbage from a perennial ryegrass sward receiving a wide range of nitrogen rates

Published online by Cambridge University Press:  27 March 2009

D. Reid
Affiliation:
The Hannah Research Institute, Ayr

Summary

The results are reported for an experiment in which nitrogen rates from 0 to 672 kg/ ha and potassium rates from 0 to 558 kg/ha were applied annually on an S. 24 perennial ryegrass sward. At each of the five crops cut annually the yields of herbage dry matter and crude protein, and the potassium content of the herbage dry matter were determined. The potassium content of the soil was also measured annually. Models relating each of these variates to the nitrogen and potassium rates were derived, and their validity is demonstrated with reference to the results from earlier experiments. The problems associated with determining the correct rate of potassium fertilizer to apply on swards receiving given rates of nitrogen fertilizer are discussed using the models to predict the effects of different nitrogen-potassium combinations. In order to relate the implications of this discussion more closely to practical grassland management, economic as well as biological criteria are taken into account by incorporating cost factors in the models.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1980

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. Journal of Agricultural Science, Cambridge 55, 251260.CrossRefGoogle Scholar
Clement, C. R. & Hopper, M. J. (1968). The supply of potassium to high yielding cut grass. NAAS Quarterly Review 79, 101109.Google Scholar
Reid, D. (1970). The effects of a wide range of nitrogen application rates on the yields from a perennial ryegrass sward with and without white clover. Journal of Agricultural Science, Cambridge 74, 227240.CrossRefGoogle Scholar
Reid, D. (1978). The effects of frequency of defoliation on the yield response of a perennial ryegrass sward to a wide range of nitrogen application rates. Journal of Agricultural Science, Cambridge 90, 447457.CrossRefGoogle Scholar
Reid, D. & Strachan, N. H. (1974). The effects of a wide range of nitrogen rates on some chemical constituents of the herbage from perennial ryegrass swards with and without white clover. Journal of Agricultural Science, Cambridge 83, 393401.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. Part I. The effect of nitrogen, phosphate and potash on yield. Journal of Agricultural Science, Cambridge 56, 1729.CrossRefGoogle Scholar