Nitrogen Transformations As Affected By Some Factors at Cultivated Soils In Saudi Arabia

Abstract

The influence of serial concentration of salts (0.5, 1.0 and 1.5%), application of organic matter (0.5, 1.0 and 1.5% of wheat straw) and varying soil moisture content (50, 70 and 90%) on nitrification in sandy loam soil was studied. Ammonium sulphate (5 mg N g'' soil) was added and the soil samples were incubated at 25°C for 4 weeks. Increased salinity delayed or inhibited nitrification. Addition of organic matter enhanced nitrification processes. The nitrification rate showed progressive increase with time at 70% water holding capacity, but as moisture content increased the nitrate production decreased.