Adoption Potential of Hedgerow Intercropping in Maize-Based Cropping Systems in the Highlands of Western Kenya. 1. Background and Agronomic Evaluation

The biophysical performance of hedgerow intercropping for soil fertility inprovement was assessed in a farmer-participatory trial in western Kenya over three years. Farmers successfully established dense hedgerows (median 6680 trees ha −1 on plots of 790 m 2 , but annual yields of hedgerow prunings of Leucaena leucocephala and Calliandra calothyrsus (1–4 t ha −1 ), were low compared to potentials in the region (4–8 t ha −1 ). The hedgerows reduced slopes from 7.2 to 4.5% within alleys ( p < 0.01) but had no effect on grain yield over five seasons. Little of the variation in grain yield between hedgerow plots and control plots without hedgerows (adjusted r 2 = 11%) and among control plots (adjusted r 2 = 29%) could be accounted for by linear regression with measured agronomic and socio-economic variables. Fully researcher-managed trials are recommended for agronomic evaluation of complex agroforestry technologies.