Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-23T03:02:19.140Z Has data issue: false hasContentIssue false

A comparison of the effects of single or multiple spring applications of prilled urea or ‘Nitro-chalk’ to winter oilseed rape (Brassica napus)

Published online by Cambridge University Press:  27 March 2009

R. J. Darby
Affiliation:
AFRC Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts, AL5 2JQ, UK
M. V. Hewitt
Affiliation:
AFRC Institute of Arable Crops Research, Rothamsted Experimental Station, Harpenden, Herts, AL5 2JQ, UK

Summary

An earlier report of leaf scorch and diminished yield when using large amounts of urea on winter oilseed rape (Brassica napus) was investigated by applying 200 kg N/ha as calcium ammonium nitrate (‘Nitro-chalk’) or urea as a single dressing or divided in six ways. The ‘single-low’ variety Mikado (low in erucic acid) was grown in 1986 and was compared with the ‘double-low’ variety Ariana (low in erucic acid and glucosinolates) in 1987 and 1988. No scorch was seen in these experiments. Yield from rape fertilized with prilled urea was, on average, 98% of that from rape fertilized with ammonium nitrate. The timing and distribution of the fertilizer also had little effect on yield, though yield slightly decreased when part of the dressing was withheld during March. The earlier-maturing variety Mikado always outyielded Ariana except when harvest was delayed by bad weather.

When plots were fertilized with urea, the oil content of the seed was a little larger than when fertilized with Nitro-chalk, which compensated for the smaller seed yield, resulting in almost equal oil yield from both forms of N fertilizer. Crude protein content was lower after a large single dose of urea fertilizer but parity with ammonium nitrate was restored by smaller amounts applied on a number of occasions. Neither form nor timing of N fertilizer had any consistent effect on the total glucosinolate content.

The incidence of disease was significantly greater in rape given either form of N fertilizer than where none was given, but when downy mildew (Peronospora parasitica) was prevalent on pods there was significantly less infection in plots fertilized with urea than with ammonium nitrate.

Type
Crops and Soils
Copyright
Copyright © Cambridge University Press 1990

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

REFERENCES

Anon (1986). Recommended varieties of oilseed rape 1987. Farmers' Leaflet, National Institute of Agricultural Botany, No. 9.Google Scholar
Draper, S. R., Kingston, I. B. & Holden, M. (1979). Procedures for the comparative assessment of quality in crop varieties. 1. Methods of analysis and assessment. Journal of the National Institute of Agricultural Botany 15, 114.Google Scholar
Elsmere, J. I. (1988). Use of fertilizers in England and Wales 1987. Report of the Rothamsted Experimental Station for 1987, pp. 187194.Google Scholar
Gasser, J. K. R. (1964). Urea as a fertilizer. Soils and Fertilizers 27, 175180.Google Scholar
Heaney, R. K., Spinks, E. A. & Fenwick, G. R. (1988). Improved method for the determination of the total glucosinolate content of rapeseed by determination of enzymically released glucose. Analyst 113, 15151519.CrossRefGoogle ScholarPubMed
Holmes, M. R. J. (1980). Nutrition of the Oilseed Rape Crop. Barking, England: Applied Science.Google Scholar
Ministry of Agriculture, Fisheries and Food (1985). Fertilizer Recommendations 1985–86. Reference Book 209, p. 25.Google Scholar
Morgan, A. G. & Cooke, R. J. (1989). Quality testing in oilseed rape. Aspects of Applied Biology 23, 3746.Google Scholar
Mudahar, M. S. & Hignett, T. P. (1982). Energy and fertilizer. Technical Bulletin, International Fertilizer Development Center. T. 20, 4446.Google Scholar
Rawlinson, C. J., Muthyalu, G. & Cayley, G. R. (1984). Fungicide effects on light leaf spot, canker, crop growth and yield of winter oil-seed rape. Journal of Agricultural Science, Cambridge 103, 613628.CrossRefGoogle Scholar
Rodgers, G. A., Penny, A. & Hewitt, M. V. (1986). A comparison of the effects of prilled urea, used alone or with a nitrification or urease inhibitor, with those of ‘Nitro-Chalk’ on winter oil-seed rape. Journal of Agricultural Science, Cambridge 106, 515526.CrossRefGoogle Scholar
Rothamsted Experimental Station (1987, 1988, 1989). Winter oilseed rape, forms and times of N. Yields of the Field Experiments 1986, 1987, 1988.Harpenden: Lawes Agricultural Trust.Google Scholar
Sweet, J. B., Pope, S. J., Sparks, T., Martin, S., Priestley, R. H. & Varney, P. L. (1988). Alternaria infection levels in oilseed rape varieties. Aspects of Applied Biology 17, pt. 2, 229233.Google Scholar
Varley, J. A. (1966). Automatic methods for the determination of nitrogen, phosphorus and potassium in plant material. Analyst 91, 119126.CrossRefGoogle Scholar