A field experiment consisting of one soil (sandy), four organic materials (compost, sewage sludge, dairy manure, poultry manure) and three plants (Prosopis juliflora, Acacia arabica and Atriplex halimus), four application rates (0, 25, 50, 75 Mg ha^-1) and one irrigation level (irrigation at 20 % depletion of maximum available water at field capacity) was carried out to determine the potential of locally produced organic materials for restoring productivity and rehabilitation of sandy soils in Saudi Arabia. Mean biomass yield of Acacia Arabica (Mg ha^-1) ranged between 31-39 (compost), 25-53 (sewage sludge), 18-67 (dairy manure) and 19-82 (poultry manure). Mean protein contents of Acacia Arabica (%) ranged between 6.32-7.27 (compost), 6.11-8.10 (sewage sludge), 6.8-7.56 (dairy manure) and 7.59-8.43 (poultry manure). Mean biomass yield of Prosopis Juliflora ( Mg ha^-1) ranged between 21-52 (compost), 51-107 (sewage sludge), 43-87 (dairy manure) and 52-156 (poultry Manure). Mean protein contents of Prosopis juliflora (%) ranged between 9.26-10.45 (compost), 10.41-11.37 (sewage sludge), 9.6-11.07 (dairy manure) and 9.3-10.93 (poultry manure). Mean biomass yield of Atriplex halimus (Mg ha^-1) ranged between 1.2-10.1 (compost), 11-37 (sewage sludge), 5-45 (dairy manure) and 5-57 (poultry manure). Mean protein contents of Atriplex halimus (%) ranged between 7.35-8.38(compost), 4.11-5.47 (sewage sludge), 4.40-4.93 (dairy manure) and 3.68-4.59 (poultry manure). Soil salinity increased appreciably with the application of different organic waste materials than the control treatment.

Overall mean biomass yield of all the plants increased significantly with increasing application rates of different organic materials. The order of increase in biomass yield was poultry manure > dairy manure> sewage sludge and the compost. The plant protein contents were not affected significantly by the application of different organic materials. These organic materials showed an excellent potential for rehabilitation and improving the productivity of sandy soils.

Keywords: Poultry manure, sewage sludge, dairy manure, compost, Acacia arabica, Prosopis juliflora, Atriplex halimus, nutrients, soil productivity, biomass yield.