Abstract
Series of incubation experiments were conducted to study the effect of three different organic amendments (olive waste, compost and lemon waste) on some chemical properties of calcareous soil. Soil samples were collected from northwestern coast of Egypt (Borg El Arab) from the surface soil (0-30 cm). The samples were then air-dried and then grinded, sieved (2 mm) and analyzed some physical and chemical properties. Samples were used in laboratory experiment, where organic amendments were applied to soil with different rates (0, 0.5, 1, 1.5 and 2% (w w-1). The prepared pots were incubated for four months at temperature between 23 to 30 °C. After 4, 8, 12 and 16 weeks of the incubation, the soil samples were taken for analysis soil pH, electrical conductivity (EC) and total equivalent calcium carbonate. The results showed that compost, olive waste and lemon waste could change the chemical properties of the calcareous soils. All organic amendments caused an increase in soil EC while they slightly decreased soil pH and CaCO3 content. The compost was showed to have effectivity effect on soil pH comparing to other amendments, while lemon waste and olive waste were showed to have effectivity effect on CaCO3 content after few weeks of application. This can be explained on the basis that the olive waste and lemon waste are less biodegradable than that of compost. Finally, it is concluded that olive waste and or lemon waste can be used in preparing any compost to be more useful.