A field experiment was conducted to investigate the effects of different nitrogen application levels and planting patterns on the yield, nitrogen uptake, and root morphology of maize and alfalfa. Two nitrogen application levels（N₀ and N₁） and four planting patterns（MM, MA, IMA46, IMA26） were established. The results showed that N application significantly increased the yield and N uptake of maize and alfalfa. Under the conditions without N fertilizer（N₀）, compared to maize monoculture（MM）, IMA46 and IMA26 treatments could increase maize yield, nitrogen uptake, root length, root surface area and root volume by 72.9%, 138.6%, 37.0%, 34.7%, 43.0% and 41.1%, 73.5%,18.7%, 8.8% and 18.4%, respectively. With N fertilization（N₁）, compared to maize monoculture（MM）, IMA46 and IMA26 treatments could increase maize yield, N uptake, root length, root surface area and root volume by 21.9%,56.7%, 41.0%, 21.7%, 30.4% and 6.8%, 21.2%, 25.5%, 12.2%, 14.6%, respectively. Additionally, whether nitrogen was applied or not, compared to alfalfa monoculture（MA）, alfalfa’s root length, root surface area, and root volume in intercropping systems were reduced to varying degree. In conclusion, in terms of crop yield value, nitrogen uptake, and root configuration, the IMA46 model outperformed the others, and is recommended for widespread application in regions with white pulp soil.