02409naa a2200229 a 450000100080000000500110000800800410001902400280006010000220008824501350011026000090024552017030025465000190195765000260197665000160200265300150201865300220203370000160205570000170207170000220208877300690211015242202024-01-10 1997 bl uuuu u00u1 u #d7 a10.1007/BF019857202DOI1 aAKINNIFESI, F. K. aNitrogen use efficiency and N-competition between Leucaena hedgerows and maize in an alley cropping system.h[electronic resource] c1997 aAbstract: A two-year field experiment was undertaken on an Alfisol in the forest-savanna transition zone of southwestern Nigeria, to study the effect of alley cropping, root barrier, application of N fertilizer andLeucaena leucocephala (Lam.) de Wit. prunings, on N utilization by maize andLeucaena hedgerows. The trial was conducted using a split-plot design with three replications. Mainplot treatments were alley cropping withLeucaena leucocephala planted at 4m interhedgerow spacing and control (no hedgerows). Four subplot treatments were with and without addition of hedgerow prunings, and with and without presence of root barriers. There were no significant effects of presence ofLeucaena hedgerows and root barriers on maize grain yield.Leucaena hedgerows recovered about 7% of the 30 kgN/ha applied as (15NH4)2SO4 to maize during one year. Application of hedgerow prunings increased maize yield by 82% and N-uptake in the grain by 50% over the treatment without prunings. Recoveries of15N-labelled prunings and fertilizer N by maize plants were about 10 and 16% respectively. Prunings addition increased15N-fertilizer recovery in main season maize and the residual value during the minor season by about 36% over the treatment without prunings. Pruning N-use efficiency was higher for plants grown adjacent to the hedgerows than in the middle of alleys during main season and the reverse was observed during the minor season. Absence of a root barrier increased N-use from prunings. Large amounts of applied N in the system were unaccounted for. Results of the trial showed, that without root barrier there was no measurable below-ground N competition betweenLeucaena hedgerows and maize. aNitrogen cycle aLeucaena Leucocephala aNitrogĂȘnio aCompeticao aCultivo em Aleias1 aKANG, B. T.1 aSANGINGA, N.1 aTIJANI-ENIOLA, H. tNutrient Cycling in Agroecosystemsgv. 47, n. 1, p. 71-80, 1997.