A Study on the Extractable Copper as Related to Soil Texture and Lime Content in some Jeffara Soils

الملخص

Experiments were conducted in the laboratory and in the greenhouse to study the status of copper in some Jeffara soils as related to the growth and performance of tomato plants.
Laboratory work included several attempts to relate the status of available Cu to certain soil constituents. These were: organic matter, carbonate, and soil mechanical analysis. Three types of soils: black, red. and alkali soils were used to assess the role of organic matter and carbonate, in copper retention by the soil. Results obtained showed that the majority of available Cu, as indicated by the extractable Cu, is held either with the soil organic matter or combined with calcium carbonate. The relative easiness of converting any of these forms to an available form is, however, variable.
Another attempt was concerned with the relationship between soil mechanical analysis. carbonate, and the level of extractable copper in the soil. Three profiles were dug in the experimental farm of the University of Libya in Sidi El Mesri area. Samples were taken from successive layers in each profile. The copper content was shown to be associated with the soil separates more than to its content of calcium carbonate. This was verified in a third experiment using two different solvents for the extraction of copper.