Investigation of Nitrogen Fixation in the Loam Clay Sandy Rangeland Soil with Kraft Lignin

Nitrogen is one of the most important factors affecting the efficiency and soil fertility and the development of cultivated plants, as the most yield-limiting nutrient element in crop production in most soils worldwide. In this study the effects of lignin addition on nitrification in loamy clay sandy soil was investigated in the greenhouse. Therefore soil treated with different rate of lignin ( 0, 50 and 200 mg per kg soil). Lignin used in this study was obtained from black liquor the Kraft process. The results of this study showed that addition of lignin to soil pronouncedly affects the amount of NH4 , NO3-and total soil nitrogen (p