The Disposal of Biosolids and Water Treatment Residuals on Soils of Arid Regions: Effect on Wheat Biomass and P and Al Availability

ABSTRACT:-Land co-application of biosolids and WTR is a new concept. Therefore, information on the effect of co-application of biosolids and WTR on plant growth and elements uptake are very limited especially in alkaline soils. A glasshouse experiments was established to evaluate the effects of co-application of WTR and biosolids on agronomic performance of wheat crop grown in alkaline soils as well as P and Al plant concentration and uptake, and to improve management of industrial and toxic wastes and provides environmentally sound guidelines for their disposal. The results indicated that increases of 47, 359 and 55 % in total dry matter yield were achieved as a result of applying 40 gkg-1 WTR and 10 gkg-1 biosolids to clay, sandy and calcareous soils respectively. In all studied soils treated with a constant biosolid rate 10 gkg-1, application of 20 gkg-1 WTR significantly increased plant P concentration in the plant materials. Combined analyses of all soils,all treatments of biosolid and WTR rates studied indicated clearly significant relationships between ABDTPA P concentration and P uptake (r = 0.81, p < 0.001). Application of WTR combined with biosolid showed significant increases in extractable Al in all the soils studied. However, application rates of WTR and biosolid did not increase extractable Al in amended soils beyond 6.06 mg Al kg-1