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Site-factor Influence on Barley Response to Fertilizer in On-farm Trials in Northern Syria: Descriptive and Predictive Models

Published online by Cambridge University Press:  03 October 2008

M. J. Jones  and
A. Wahbi
M. J. Jones
Affiliation:
International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria
A. Wahbi
Affiliation:
International Center for Agricultural Research in the Dry Areas (ICARDA), Aleppo, Syria
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Summary

The effects of site and rate of application of fertilizer on the grain and straw production of barley were investigated in 75 trials on representative farmers' fields. Grain and straw production were strongly but curvilinearly correlated with growth-period rainfall over the range 136–568 mm, almost irrespective of soil type, previous crop or fertilizer rate, and responded positively to applied nitrogen and/or phosphorus in 74 of the trials. Responses to nitrogen increased and those to phosphorus decreased with increasing rainfall. Yields tended to be lower but responses to nitrogen were higher where barley followed barley and were influenced by the availability of phosphate and mineral nitrogen in the soil at planting time.

These results are summarized in regression equations, which express yield quadratically in terms of fertilizer rates, seasonal rainfall and their interactions over the full 75-trial data set and within representative sub-sets. The wide differences in crop response to fertilizer highlight the problem of recommending fertilizer rates for a low and variable rainfall environment. Simple second-order multiple regressions for different geographical areas, rainfall zones, crop rotations etc., based on mean rainfall values, account for around 40% of the variance in yield response to nitrogen and phosphorus fertilizer; only a small proportion of the remaining variance appears attributable to rainfall variability. Alternatively, yield may be expressed as a function of fertilizer rate and rainfall using rainfall probability values derived from long-term records. This can be used to estimate the probabilities of predetermined yield responses for specified sites and fertilizer rates and to produce maps of those probabilities.

Type
Research Article
Information
Experimental Agriculture , Volume 28 , Issue 1 , January 1992 , pp. 63 - 87
Copyright
Copyright © Cambridge University Press 1992

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References

REFERENCES

Arnon, I. (1972). Crop Production in Dry Regions. Volume I. London: Leonard Hill.Google Scholar
Colwell, J. D. & Morton, R. (1984). Development and evaluation of general or transfer models of relationships between wheat yields and fertilizer rates in Southern Australia. Australian Journal of Soil Research 22:191–205.CrossRefGoogle Scholar
Cooper, P. J. M. (1983). Crop management in rainfed agriculture with special reference to water use efficiency. In Proceedings 17th Colloquium of the International Potash Institute, 63–79. Bern, Switzerland.Google Scholar
Cooper, P. J. M., Gregory, P. J., Tully, D. & Harris, H. C. (1987). Improving water use efficiency of annual crops in the rainfall farming systems of West Asia and North Africa. Experimental Agriculture 23:113–158.CrossRefGoogle Scholar
Goebel, W. (1989). A spatial rainfall generator for regions with suboptimal data availability and quality. In Annual Report for 1988, 106–116. Aleppo, Syria: Farm Resource Management Program, ICARDA.Google Scholar
Harmsen, K. (1984). Dryland barley production in northwest Syria: 1. Soil conditions. In Proceedings of the Soils Directorate/ICARDA Workshop on Fertilizer Use in the Dry Areas, 12–41. Aleppo, Syria: ICARDA.Google Scholar
Harmsen, K., Shepherd, K. D. & Allan, A. Y. (1983). Crop response to nitrogen and phosphorus in rainfed agriculture. In Proceedings 17th Colloquium of The International Potash Institute, 223–248. Bern, Switzerland.Google Scholar
Krentos, V. D. & Orphanos, P. I. (1979). Nitrogen and phosphorus fertilizers for wheat and barley in a semi-arid region. Journal of Agricultural Science, Cambridge 93:711–717.CrossRefGoogle Scholar
Matar, A. E. (1977). Yields and response of cereal crops to phosphorus fertilization under changing rainfall conditions. Agronomy Journal 69:879–881.CrossRefGoogle Scholar
Mazid, A. & Hallajian, M. (1983). Crop-livestock interactions. Information from a barley survey in Syria. Research Report No. 10. Aleppo, Syria: Farming Systems Program, ICARDA.Google Scholar
Shepherd, K. D., Cooper, P. J. M., Allan, A. Y., Drennan, D. S. H. & Keatinge, J. D. H. (1987). Growth, water use and yield of barley in Mediterranean-type environments. Journal of Agricultural Science, Cambridge 108:365–378.Google Scholar