A pot experiment was conducted using a sandy loam soil cultivated with sorghum plant. This investigation aimed to study the effect of different treated of municipal wastewater and fertilization on availability of some nutrients after harvesting of sorghum. The experiment consisted of 4 sources of irrigation water namely: 1- well water, 2- primary treated wastewater, 3- secondary treated wastewater and 4- tertiary treated wastewater. In addition, 6 fertilization treatments were applied namely: 1- control, 2- 100% NPK, 3- 50% NPK, 4- 25% NPK 5- 100% PK and 6- 100% NK from the recommended dose of NPK fertilizers for sorghum plant.
The obtained results demonstrated that application of primary treated wastewater resulted in a significant increase in available N at the studied soil depths. The data further indicated that application of 100% NPK treatment gave a significant increase in available N at the various soil depths.
The results also, indicated that the effect of primary treated wastewater was the most conspicuous on available P content of the soil and resulted in a higher available P content as indicated by soil test data. The fertilizer treatments increased the available P at 0-20 cm depth in comparison with the control and 100% NK treatments.
Available K level was increased by applying all water treatments. Application of the secondary wastewater treatment increased significantly available K level at the depth of 0-20 cm, whereas there are no significant differences at the other soil depths. All fertilizer treatments increased slightly available K at various soil depths.
The results indicated that applying well water increased significantly available Cu at 0-20 cm depth in compared with the different treated wastewaters. Nevertheless, the data showed that level of available Zn and Mn was higher under primary and tertiary treated wastewater treatments. Level of available Fe was not affected by using water treatments.
The fertilizer treatments did not result in any significant difference in available Cu, Zn, Mn and Fe.