Effect of Nitrogen Application on Urease Activity in Rhizosphere Soil of Wheat and Faba Bean Intercropping System

Urease activity influences the transformation of urea and nutrients utilization of crops in soil. Field experiment was conducted to investigate the effects of nitrogen application rates on urease activity of rhizospheric soil in wheat//faba bean system, nitrogen application rates of wheat were 0(N0), 112.5(N1), 225.0(N2), 337.5(N3)kg/hm2; The nitrogen application rate of faba bean was the half of the wheat. The results showed that nitrogen application could improve the yield of wheat//faba bean and the LER of N0, N1, N2 and N3 were 1.15, 1.10, 1.05 and 1.02, respectively. The wheat//faba bean intercropping system had advantage of yield. Nitrogen application influenced the urease activity in the rhizospheric soil of wheat and faba bean. Compared with monocropping, in the tillering stages, the urease activity in rhizospheric soil of wheat in intercropping system increased by 4.66% and the order of increasing amount was N0N2N1N3, while the urease activity in rhizospheric soil of faba bean in intercropping increased by 6.60% and the order of increasing amount was N2N1N0N3. In the jointing stages, the urease activity in the rhizospheric soil of wheat in intercropping increased by14.08% and the order of increasing amount was N2N1N3N0, while the urease activity in rhizospheric soil of faba bean in intercropping increased by 8.24% and the order of increasing amount was N0N2N1N3. In the maturing stages, the rhizospheric soil urease activity of wheat in intercropping increased by 7.03% and the order of increasing amount was N2N3N1N0, while the rhizospheric soil urease activity of faba bean in intercropping are increased by 5.25% and the order of increasing amount was N0N1N2N3. It is concluded that the level of nitrogen application have a great influence on the urease activity in rhizospheric soil of wheat and faba bean in wheat//faba bean system.