Characteristics and productivity of a sandy soil as influenced by soil conditioners in Saudi Arabia

A pot experiment was conducted in Central Saudi Arabia during the winter season of 1989 to investigate the effect of three soil conditioners, applied in different combinations with urea as N-fertilizer, on some soil characteristics and productivity of wheat. The conditioners used were: super organic compost (4% w/w.), vermiculite (4% w/w.) and hydro-grow 400 (0•2% w/w.). The obtained results indicate that all the investigated soil properties were variably influenced by the applied soil conditioners. Relative to untreated soil, soil bulk density, quickly and slowly drainable pores and saturated hydraulic conductivity were negatively influenced, whereas available water range, total porosity, water holding pores, and cation exchange capacity of the soil were positively influenced. The results also showed that the soil conditioners improved nitrogen uptake, yield components and yield quality of wheat. The extent of improvement varied, depending on the type of soil conditioner used and rate of urea. At the rate of 600 and 900 kg urea ha-1, the effect of soil conditioners on nitrogen uptake, straw and grain yields, grain protein content and % nitrogen recovery in grains followed the order: super organic compost > hydro-grow 400 > vermiculite.