Abstract This study was performed to evaluate the ability
of cellulolytic fungi and wheat straw incorporation to
improve the nodulation, growth and nitrogen status of fenugreek
grown in saline soils. NaCl addition to the growth
medium at rates of 0.5 and 1% strongly decreased the enzymatic
activity of the ten tested moulds. Three of these
fungi, Aspergillus niger, Chaetomium globosum and Trichoderma
harzianum, showed the highest enzymatic activity.
The three moulds have the ability to degrade straw in
the presence of NaCl and T. harzianum was the best straw
degrader. Inoculating the plants with Rhizobium meliloti
strain TAL 1373 and cellulolytic fungi slightly promoted
nodulation, growth and nitrogen accumulation when plants
were grown with the addition of 0.5% NaCl when compared
to plants inoculated with R. meliloti alone. However,
application of wheat straw with cellulolytic fungi significantly
enhanced growth, nodulation and nodule efficiency
at 0.5 and 1.0% salinity. The greatest values of nodulation
and growth parameters were obtained with a straw-Trichoderma
harzianum combination. Cellulolytic fungi and
wheat straw increased the concentration of Ca, Mg and K
in the shoots and roots of plants. The increase in dry matter
production and N content was mainly due to improved
N2 fixation reflected by enhanced formation and growth of
nodules as well as nitrogenase activity.