Soil fertility and productivity aspects of alley cropping schemes using leguminous trees as hedgerows and corn (Zea mays L.) as an alley crop

Soil texture and particle density did not change significantly after the experiment. The soil was clay loam before the experiment and remained unchanged. Particle density significantly increased irrespective of treatments after the experiment but did not differ significantly among the plots. Water holding capacity of the soil increased but not statistically significant in the Acacia villosa and Gliricidia sepium plots. Corn monoculture plot had a significantly low water holding capacity after the experiment. Soil pH exhibited a significant decline after the experiment irrespective of treatments. Organic matter contents of the soil increased but not statistically significant in the hedgerow intercropping plots (treated) and decreased in the monoculture (control) plots. Cation exchange capacity (CEC) did not vary significantly among the plots before and after the experiment. Monoculture plot, however, showed a sharp but not statistically significant decline in CEC after the experiment. Statistical analyses revealed no significant differences among the plots in their P, K, Ca, and Na contents before and after the experiment. Gliricidia sepium produced the highest fresh weight of herbage and also had the lowest percentage dry matter or herbage. N and P contents of herbage did not vary significantly among the hedgerow species while K was found to be significantly high in the G. sepium herbage. Acacia villosa herbage had a faster rate of dry matter disappearance and NPK release from its litter than G. sepium and L. diversifolia. Stover and grain yields of corn generally improved in the treated plots but decreased in the monoculture plot. Gliricidia sepium alleys exhibited the highest grain yield in the third cropping. NPK contents of corn stover did not vary significantly among the plots. Presence of trees in the treated plots minimized runoff and sediment yield.