The effects of a wide range of nitrogen application rates on the yields from a perennial ryegrass sward with and without white clover
- 1 April 1970
- journal article
- research article
- Published by Cambridge University Press (CUP) in The Journal of Agricultural Science
- Vol. 74 (2), 227-240
- https://doi.org/10.1017/s002185960002284x
Abstract
SUMMARY: A series of twenty-one nitrogen fertilizer rates ranging from 0 to 800 lb nitrogen/acre (897 kg/ha)/annum was applied on a pure S. 23 perennial ryegrass sward and on an S. 23 ryegrass sward containing S. 100 white clover. Total yields of herbage dry matter and crude protein from both swards at all the nitrogen rates were determined each year by cutting the herbage five times at approximately the same stage of growth on each occasion. Four-parameter growth curves relating herbage yield to nitrogen rate were fitted to the data, and are presented for the first 3 years of the experiment. On the pure-grass sward the response of dry-matter yield to nitrogen rate was almost linear between the 0 and 300 lb nitrogen/acre (336 kg/ha) rates, then it decreased steadily, becoming non-significant about the 500 lb/acre (560 kg/ha) rate. In contrast the response of crude-protein yield was virtually linear from the 0 to the 600–700 lb nitrogen/acre (673–785 kg/ha) rates. The inclusion of white clover in the sward increased the yields of dry matter and crude protein at the low nitrogen rates, but decreased the responses, with the result that the yields and responses of the grass + clover sward were not significantly different from those of the pure-grass sward at nitrogen rates above about 300 lb/ acre (336 kg/ha). In terms of profitability at present fertilizer prices the optimum nitrogen rate for dry-matter production on both swards was estimated to be 400–450 lb/ acre (448–504 kg/ha), whereas that for crude-protein production was greater than 600 lb/acre (673 kg/ha). The value of clover in a sward receiving nitrogen fertilizer is discussed.Keywords
This publication has 5 references indexed in Scilit:
- A COMPARISON OF THE REACTION OF DIFFERENT GRASS SPECIES TO FERTILIZER NITROGEN AND TO GROWTH IN ASSOCIATION WITH WHITE CLOVER. I. Yield of dry matterGrass and Forage Science, 1965
- The response of grass-clover and pure-grass leys to irrigation and fertilizer nitrogen treatment. II. Clover and fertilizer nitrogen effectsThe Journal of Agricultural Science, 1965
- THE USE OF NITROGEN ON GRASS/WHITE-CLOVER SWARDS*Grass and Forage Science, 1963
- NITROGEN AND HERBAGE PRODUCTION*Grass and Forage Science, 1963
- CLOVER NITROGEN AND SWARD PRODUCTIVITYGrass and Forage Science, 1960