الفهرس 
The effect of soil moistureOnly 14 pages are availabe for public view
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Abstract
The present study was conducted to investigate the mem population density of the earthworm Aporrectodea caliginosa and its develpmental stages in Monoufia Govemorate,and to evaluate its role in improving the soil characteristics. The determination of the toxicity of some pesticides currently used in Egypt against these worms as well as their impacts on the worm’s role in soil was considered. In addition, the effect of some additives on the role undertaken by A. calzginosa in changing soil properties was assessed. The mean population density of the adult and immature worms as well as cocoons in arable and orchard soils was determined in eight centers in Monoufia Governorate; namely Tala, Birket el-Sab, Quweisna, Shibin - El- Kom, El-Shuhada, El-Bagour- Menouf and Ashmoun. Determination of some physic0 - chemical properties of the investigated soils was considered . On the other hand, soil contents of urea, nitrogen protein, C/N and essential elements; Na, K , Mg, Ca, in addition to the total soluble salts and pH were used as the main criteria for evaluating of the extent of the role undertaken by the worm to improve soil characteristics. For micological investigation, tZ1e LC50 of nine pesticides belonging to three categories were estimated. The pesticides studied were larvin, lannate, pirimor, malathion and actellic (as insecticides), risolex, cuprosan and diathane (as fungicides) and kalthane (as acaricide ). The effect of the exposure of the worm to 1/10 of the LC5o of each pesticide on its role in soil transformation was determined. The same previously mentioned criteria were used as indicatives of the extent interference of these pesticides with such role of the worms. To investigate the effect of additives on the worm’s role in changing soil properties, five types of additives were used; gypsum and decayed plant litter as well as three other industrial disposals and wastes which are sugarcane plant fibers (mollasses), residues of cotton seed and lineseed left fiom oil industries. Each additive was added to the soil witfa a concentration of 1% to study its effect on the worm’s role. Also, the previous criteria were used to indicate the additive effects on the worm’s role.