Two field experiments were conducted at Sakha Agricultural Research Station Farm, Kafr El-Sheikh Governorate, Egypt during the two successive growing seasons, winter 2011/2012 and summer 2012 to evaluate the effect of application different rates i.e. 0, 5, 10, 20 & 30 ton fed^-1 of organic amendments (farmyard manure "FYM" and poultry manure "PM") on some soil characteristics and yield of wheat and soybean. The obtained results could be summarized as follow: 1) Application of organic amendments (farmyard and poultry manures) improved some soil physical properties through decreasing soil bulk density and penetration resistance, while total porosity, infiltration rate, aggregation index, mean weight diameter and optimum size aggregates were increased. 2) Increasing organic amendments application rates up to 30 ton fed^-1 led to a slight decrease in soil pH and remarkable increase in soil salinity, organic matter content and soil elemental contents. 3) The yields of both wheat and soybean crops were increased significantly with increasing the application rate of organic amendments. The yield increment due to PM surpassed that due to FYM by about 2.4%. It could be concluded that utilization of farmyard manure and poultry manure as an organic fertilizer is essential in improving soil productivity and crop production, through enriching the soil with nutritional elements and their beneficial effects on the physical and chemical characteristics of soil, as well as minimizing the intensive use of chemical fertilizers, consequently decrease their negative impact on the environmental and economical conditions.