A pot experiment was conducted to investigate the effect of application of three rates of compost (40, 60 and 80 g/pot) and inoculation with VA mycorrhizae on growth of wheat and maize plants grown in clay loam and sandy soils. VA mycorrhizal root colonization was also studied.
The results revealed that the increasing of organic fertilization resulted in increases in growth measurements of both plants, (i.e. plant height, root length, fresh weight, dry weight, percentage of infection with mycorrhizae and N and P percentage). Inoculation of wheat and maize plants with mycorrhizae led to high significant increases in the above-mentioned parameters as compared to uninoculated plants grown in the two soils. The highest values of above-mentioned measurements were recorded in plants which received 80 g compost /pot (i.e. 20 tons/ feddan), in the clay loam and sandy soils. The interaction effect between compost and inoculation with mycorrhizae was significant in the plant height, root length and N percentage of wheat in the sandy soil, as well as the interaction effect between compost and inoculation with mycorrhizae was significant in the percentage of mycorrhizal infection in the sandy soil. The interaction effect between application of compost and inoculation with mycorrhizae was significant in plant height, % mycorrhizal infection and % N of maize in the clay loam and sandy soils. The highest values of the above-mentioned parameters of wheat and maize were achieved with application of compost at the rate of 60 g/pot which represent 15 tons/ feddan combined with inoculation with mycorrhizae in both experimental soils.