Growth and N₂ fixation in mixed cropping of Medicago arborea and Atriplex halimus grown on a salt-affected soil using a ¹⁵N tracer technique

Abstract

The objective of this study was to evaluate dry matter (DM), nitrogen yield, N₂ fixation (Ndfa) and soil N uptake (Ndfs) in the shrubby medic (Medicago arborea) and saltbush (Atriplex halimus) grown in pots either solely or in a mixture on a salt-affected soil, using ¹⁵N dilution method. The combined DM of both species was considerably higher than that of solely grown shrubs. The inclusion of saltbush in the mixed cropping system decreased Ndfs by shrubby medic and enhanced % Ndfa without affecting amounts of N₂ fixed. It can be concluded that the use of mixed cropping system of shrubby medic and saltbush could be a promising bio-saline agricultural approach to utilize salt affected soils in terms of forage yield and N₂ fixation.

Keywords:

• Atriplex halimus
• Medicago arborea
• mixed cropping
• salinity stress
• ¹⁵N

Acknowledgements

The author would like to thank Professor I. Othman, Director General of AECS, for his support. The technical assistance of the staff at the AECS, Department of Agriculture, is greatly acknowledged.