Effects of arbuscular mycorrizal symbiosis, organic matter and zinc rates on chemical forms of zinc in a calcareous soil under

A greenhouse experiment was conducted using corn to study the effect of arbuscular mycorrhiza, organic matter and zinc (Zn) on chemical forms of Zn in a calcareous soil. Experimental setup was factorial, based on completely randomized design with 3 replications. Treatments consisted of 3 levels of Zn (0, 5, and 10 mg Zn per kg soil), 2 kinds of organic manure (sheep manure and municipal waste compost, each at 0 or 1% w/w) and 2 levels of mycorrhiza (no inoculation and inoculation with Rhizophagus intraradices), which were added to a calcareous soil. Plants were harvested 8 weeks after emergence and the soil was used for fractionation of Zn by sequential extraction procedure. Roots were used to determine the degree of colonization. Results showed that inoculation with arbuscular mycorrhiza increased Zn bound to carbonate, organic matter and crystalline Fe-oxides but decreased the Zn bound to Mn-oxides, amorphous Fe-oxides and residual forms. All chemical forms of Zn (with the exception of soluble and exchangeable forms) increased with increasing application of Zn. Application of both kinds of organic manure increased chemical forms of Zn. Symbiosis of arbuscular mycorrhiza, organic matter and Zn increased corn plant-root mycorrhizal colonization