We hypothesized that the integration of trees and shrubs in agricultural landscapes can reduce NO3– leaching and increase utilization of subsoil N. A field survey was conducted on 14 farms on acid soils in the subhumid highlands of Kenya, where there is little use of fertilizers, to determine the effect of vegetation types (VT) on soil NH4+ and NO3– to 4m depth. The VT included maize (Zea mays) with poor growth and good growth, Markhamia lutea trees scattered in maize, natural weed fallow, banana (Musa spp.), hedgerow, and eucalyptus woodlot. The effect of VT on NH4+ was small (<1mg N kg–1). NO3– within a VT was about constant with depth below 0.25m, but subsoil NO3– varied greatly among VT. Mean NO3–-N concentrations at 0.5–4m depth were low beneath hedgerow and woodlot (<0.2mg kg–1), intermediate beneath weed fallow (0.2–0.7mg kg–1), banana (0.5–1.0mg kg–1) and markhamia (0.5–1.6mg kg–1), and high beneath both poor (1.0–2.1mg kg–1) and good (1.9–3.1mg kg–1) maize. Subsoil NO3– (0.5–4m) was agronomically significant after maize harvest with 37kg N ha–1 m–1 depth of subsoil beneath good maize and 27kg N ha–1 m–1 depth beneath poor maize. In contrast, subsoil NO3– was only 2kg N ha–1 m–1 depth beneath woodlot and hedgerow. These results demonstrate that the integration of perennial vegetation and the rotation of annual and perennial crops can tighten N cycling in agricultural landscapes.