1. Evaluation of polysulfone hollow fibres and ceramic suction samplers as devices for the in situ extraction of soil solution

   • D. L. Jones
   • A. C. Edwards

   Research Article Pages: 157 - 165

2. The course of ¹⁵N-ammonium nitrate in a spring barley cropping system

   • G. J. M. Vos
   • B. Duquet
   • J. A. Neyroud

   Research Article Pages: 167 - 175

3. Quantitative and qualitative seasonal changes in the microbial community from the phyllosphere of sugar beet (Beta vulgaris)

   • I. P. Thompson
   • M. J. Bailey
   • J. M. Whipps

   Research Article Pages: 177 - 191

4. Nitrogen uptake in barley after spring incorporation of ¹⁵N-labelled Italian ryegrass into sandy soils

   • Ingrid K. Thomsen

   Research Article Pages: 193 - 201

5. Response of tomato cultivars to salinity

   • F. Perez Alfocea
   • M. T. Estañ
   • M. C. Bolarín

   Research Article Pages: 203 - 211

6. Crop residue application increases nitrogen fixation and dry matter production in groundnut (Arachis hypogaea L.) grown on an acid sandy soil in Niger, West Africa

   • F. -P. Rebafka
   • B. J. Ndunguru
   • H. Marschner

   Research Article Pages: 213 - 222

7. Xylem-solute technique to measure N₂ fixation by Phaseolus vulgaris L.: Calibration and sources of error

   • Alexander P. Hansen
   • Benjavan Rerkasem
   • Peter Martin

   Research Article Pages: 223 - 231

8. Decay rate and substrate quality of fine roots and foliage of two tropical tree species in the Luquillo Experimental Forest, Puerto Rico

   • Janine Bloomfield
   • Kristiina A. Vogt
   • Daniel J. Vogt

   Research Article Pages: 233 - 245

9. Further evidence that zinc is required throughout the root zone for optimal plant growth and development

   • Ross O. Nable
   • Michael J. Webb

   Research Article Pages: 247 - 253

10. Ethylene and carbon dioxide concentrations of soils as influenced by rhizosphere of crops under field and pot conditions

    • T. Otani
    • N. Ae

    Research Article Pages: 255 - 262

11. Seasonal uptake of ¹⁵N-nitrate and distribution of absorbed nitrogen in peach trees

    • N. Muñoz
    • J. Guerri
    • E. Primo-millo

    Research Article Pages: 263 - 269

12. Soil aluminium effects on uptake, influx, and transport of nutrients in sorghum genotypes

    • V. C. Baligar
    • R. E. Schaffert
    • A. F. De C. Bahia Filho

    Research Article Pages: 271 - 277

13. Direct assessment of mineral phosphorus availability to tropical crops using ³²P labelled compounds

    • R. D. Armstrong
    • K. R. Helyar
    • R. Prangnell

    Research Article Pages: 279 - 287

14. Boron deficiency in soybean [Glycine max (L.) Merr.] peanut (Arachis hypogaea L.) and black gram [Vigna mungo (L.) Hepper]: Symptoms in seeds and differences among soybean cultivars in susceptibility to boron deficiency

    • B. Rerkasem
    • R. W. Bell
    • J. F. Loneragan

    Research Article Pages: 289 - 294

15. Effects of Frankia on field performance of Alnus clones and seedlings

    • O. Q. Hendrickson
    • D. Burgess
    • L. Chatatpaul

    Research Article Pages: 295 - 302

16. Effects of drought on the yellowing status and the dynamics of mineral elements in the xylem sap of declining spruce (Picea abies L.)

    • E. Dambrine
    • N. Carisey
    • A. Granier

    Short Communication Pages: 303 - 306

17. Response of soybean genotypes to boron, zinc and manganese deficiency in tissue culture

    • M. J. Graham
    • D. L. Heavner
    • J. M. Widholm

    Short Communication Pages: 307 - 310

18. Erratum

    Erratum Pages: 311 - 321

19. Erratum

    Erratum Pages: 323 - 323

20. Erratum

    Erratum Pages: 325 - 325

21. Erratum

    Erratum Pages: 327 - 327

22. Erratum

    Erratum Pages: 329 - 330

23. Corrigendum

    Erratum Pages: 331 - 331

24. Announcement

    Announcement Pages: 332 - 332

25. Acknowledgement to referees in 1992

    OriginalPaper Pages: 333 - 336

26. Contents of volume 150 (1993)

    Legacy Pages: 341 - 344

27. Author index

    Legacy Pages: 345 - 345