The effect of mycorrhizal fungal inoculation on plant yield, nutrient uptake and inoculation effectiveness under long-term field conditions

The potential effect of indigenous and selected mycorrhizal fungal inoculation and phosphorus (P) treatment on plant growth, yield, root infection and inoculation effectiveness (IE) were tested with and without methyl bromide (MBr) for three successive years under field conditions. In 1997–1999, twelve plant species were used as host plants in a Menzilat soil series (Typic Xerofluvents) in the Mediterranean coastal region of Turkey. Compared to non-inoculated control plants, mycorrhizal inoculation increased yield in some years, but not in others. The mycorrhizal inoculum increased the root colonization of garlic, horsebean, soybean, chickpea, melon, watermelon, cucumber, maize, cotton, pepper, eggplant and tomato plants compared with the non-inoculated treatments. Compared to fumigation, plant roots grown in non-fumigated soil and successfully infected by indigenous mycorrhiza, resulted with better plant growth. Plant species belonging to the Solanaceae, Leguminosae, and Cucurbitaceae showed high responses to the mycorrhizal inoculation effectiveness under both fumigated and non-fumigated soil conditions. In general, IE was higher under low P supply than under high P supply. The effects of mycorrhizal inoculation on plant P and Zn concentrations were determined: mycorrhiza-inoculated plants had a higher nutrient content than non-inoculated plants, and this was most pronounced under fumigated soil conditions. After 3 years of field experiments, it has been concluded that for (seeded) field crops, soil and plant management systems make a great contribution to indigenous mycorrhiza to improve plant development. Whereas for horticultural plants, on the other hand, (plants transplanted into the field as seedlings), mycorrhizal inoculation makes it easy to use for large agricultural areas compared with the non-inoculated plants. It can be suggested to the farmers that arbuscular mycorrhizal fungus inoculated seedlings can be used under field conditions for high yield and quality.

► Indigenous mycorrhizae species and mycorrhizal inoculation on plant growth.
► Mycorrhizal dependency of several plant species.
► Effect of indigenous and inoculation on nutrient uptake.
► Soil and crop management on yield under field conditions.