Inter-relationship between cadmium toxicity and farmy ard manure as soil conditioner under desert soil conditions

الملخص EN

A pot experiment was carried out in the greenhouse in 1998 to study the effect of Cd and soil application of a natural soil conditioner on the growth and Cd uptake of barley and sorghum plants under the conditions of Maryut and Nubaria desert areas to the depth of 30 cm.

Cadmium was applied to the soil at the rates of 0, 10, 20 and 30 mg Cd.

kg-1 soil either alone and with 50g organic soil conditioner / pot.

The pots were cultivated to barley then to sorghum plants.

Plant and soil samples were collected at the harvest of barley and at the three cuts of sorghum to follow up growth and Cd uptake.

Grain and straw yields of barley and the dry matter of sorghum were recorded.

Cadmium uptake was calculated.

Dry matter decreased significantly in retard to increased Cd level.

But, Cd content in both straw and grains of barley and in the dry matter of sorghum increased as soil cadmium increased.

Farm Yard Manure (FYM) conditioner decreased the depressive effect of Cd on dry matter production at all Cd levels.

Fine textured soil of Maryut was significantly better than the coarse soil of Nubaria.

This points to the essence of applying greater amounts of FYM to the coarse textured soils than to the fine ones in case of pollution with Cd.

The lowest Cd uptake was found in barley grains as compared with that in straw.

For sorghum, the roots retained an appreciable amount of Cd.

The tolerance and mobility indexes were calculated and proved to be good tools for evaluating Cd effects on plant performance.

Also, EDTA-extractable Cd was measured, but was not found to be a good vehicle to assess total Cd in the soil.