ABSTRACT
Rural areas generate a large amount of plant and animal residues that can be recycled and utilized instead of relocation and/or burning. This will lead to increasing the benefits from agricultural sector in rural communities and ensuring a better environment. To increase the economic output and environmental benefits of recycling agricultural residues, integrated system should be considered, e.g., energy--compost-recycled water system; composting--co-composting system; food-feed compost system, ensilage of crop residues. The present work was a pilot study for optimizing integrated systems for bioconversion agricultural residues completed by establishing a Training Center for Recycling Agricultural Residues (TCRAR) thereby ensuring the dissemination of the technical, environmental, and socioeconomic aspects to farmers, live stock producers, extensions service staff, and private sector. Three integrated subsystems for bioconversion of agricultural residues were developed. They were based on (i) energy--manure-recycled water system, (ii) composting and co-composting system, and (iii) food-feed/compost system.
Subject(s)
Agriculture , Conservation of Natural Resources , Refuse Disposal/methods , Animals , Animals, Domestic , Bioreactors , Egypt , Manure , Rural PopulationABSTRACT
The effect of varying concentrations of either NaCl or Na2CO3 (0, 10, 20, and 25 meq/100 g soil) and organic carbon (0 and 2% starch) on the activity of dehydrogenase, urease, and phosphatase (nuclease) was studied in incubated samples of alluvial clay and calcareous sandy loam soils. Moisture content was kept at 60% W.H.C. The level of 10 meq/100 g soil of either sodium chloride or sodium carbonate was stimulatory for the activity of the three enzymes studied in both soils tested. The increasing concentrations of Na2CO3 showed greater changes in the enzymatic activity than the corresponding concentrations of NaCl in both soils. Application of starch reduced the inhibitory effect of the high levels of such salts on the enzymatic activities in both soils, except for phosphatase which was depressed by Na2SO3 in starch-amended soil samples. The calcareous soil responded to the starch addition less than the alluvial soil.
Subject(s)
Oxidoreductases/metabolism , Phosphoric Monoester Hydrolases/metabolism , Soil/analysis , Urease/metabolism , Kinetics , Osmolar Concentration , Salts , Starch/pharmacologyABSTRACT
Periodical measurements for the activities of dehydrogenase, urease, and phosphatase (nuclease) were undertaken during incubation of remoistened alluvial clay and calcareous sandy loam soil samples stored (air-dried) over ten months. All enzyme activities showed fluctuating values within both incubation time and storage period. Dehydrogenase activity tended to increase by storage of samples of both soils. Urease revealed, generally, decreasing values, whilst phosphatase showed no definite trend with the lapse of storage period.
