الفهرس 
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Abstract
Field experiments were carried out during 2018 growing season in Ismailia Governorate, Egypt, to study the effect of different sources from sediment (Nasser Lake and El Shabab Canal) add solely or in combination with natural fertilizers i.e., rock phosphate (RP) + potassium feldspar (KF) with or without vermicompost (Ver) on nutrient availability, yield and nutrient uptake of maize and wheat plants under sandy soil conditions.
Soil samples for the experiment was collected from the surface layers (0-30 cm). The soil was air dried, crushed, sieved to pass through 2 mm plastic screen, thoroughly mixed and stored in plastic bags, for analysis and experimental work.
The experiment was conducted in a complete randomized block design with three replicates. The plot area was 21 m2 (3 × 7 m), each plot had five rows 60 cm apart and 7 m long. The sediment sampled collected from specific location of Nasser Lake (Aswan Government) and El Shabab Canal which contains high amount of nutrients, organic matter and low concentration of available heavy metals. Before planting, the sediment was dried, grinded and mixed with the surface soil of 15 cm near the top at a rate of 30 Mg ha-1. Some characteristics of sediment are shown in Table (2). Potassium feldspar (94 g K kg-1) treatments were thoroughly mixed with the soil at a rate of 95 kg K ha-1. Rock phosphate (15 g P kg-1) was added at a rate of 30 kg P ha.-1. Also, the treatments of vermicompost (Ver) were mixed with the soil at a rate of 2.5 Mg ha.-1. The K- feldspar inoculated with silicate dissolving bacteria, ”SDB”, (Bacillus circullans) in a concentration of (1010 cells ml-1) at rate of 20 ml kg-1 K- feldspar; mixed with soil before planting and irrigated. Also, addition Bacillus megatherium as activity in phosphorus dissolving bacteria (PDB) in the soil a rate of 2 ml kg-1 rock phosphate. SDB and PDB were obtained from the Soil Microbiology Unit; Soil, Water and Environments Research Institute of the Agriculture Research Center, Giza, Egypt.
The experiment was cultivated with maize (Zea mays L., cv. 2031 hybrid). Mineral nitrogen was added to all plots as ammonium sulphate (205 g N kg-1) at the rate of 250 kg N ha-1 soil at three equal splits, 15 day after planting (DAP) and the second and third doses were added at tillering (45 DAP) and booting (75 DAP) stages, respectively. At harvest, plant samples were separated into stover and grains, dried at 70oC, ground and digested with concentrated mixture of H2SO4/HCLO4 for chemical analysis.
After harvest of maize experiment, the second experiment was cultivated by wheat plants (Triticum aestivum L, cv. Sakha 93) in the same plots under the same treatments. Seeds of wheat were seeded per plot. Mineral nitrogen was added to all plots as ammonium sulphate (205 g N kg-1) at the rate of 150 kg N ha-1 soil at three equal splits, 15 day after planting (DAP) and the second and third doses were added at tillering (45 DAP) and booting (75 DAP) stages, respectively. At harvest, plant samples were separated into straw and grains, dried at 70oC, ground and digested with concentrated mixture of H2SO4/HCLO4 for chemical analysis. In the end experiments, Soil samples (0-30 cm) were collected from different locations of the experimental