Nitrogen fixation in biological soil crusts from the Tengger desert, northern China

► Nitrogenase activity of biological soil crusts was 2.6-16.6 mmol m−2 h−1 in the Tengger Desert. ► Potential nitrogen input was 3.7-13.2 gN m−2 a−1. ► Nitrogenase activity of crusts was dependent on crusts type, precipitation and temperature. ► A simulated precipitation of 0.65-1.83 mm could trigger the maximum nitrogenase activity. ► Favorable temperature for nitrogenase activity varied in relation to crusts type.