Assessing the adoption potential of hedgerow intercropping for improving soil fertility, western Kenya

The biophysical and socioeconomic performance of hedgerow intercropping for soil fertility improvement was assessed in a farmer-participatory trial in western Kenya over 3 years. Farmers successfully established dense hedgerows but planting and pruning considerably increased labour use during the busiest period of the year. Women did not generally prune the hedges. The yields of hedgerow prunings of Leucaena leucocephala and Calliandra calothyrsus (1–4 t ha1 year1, n = 24) were low compared to potentials in the region (4–8 t ha1). The hedgerows had no effect on grain yield over five seasons. But they reduced slopes from 7.2 to 4.5% within alleys (P < 0.01) and thus were likely to have decreased soil erosion. The average extra maize yield required each year, beginning in the second year, to cover the added cost of hedgerow intercropping was 10.5% (SD = 5.5%) when based on returns to land, and 17.5% (SD = 6.5) based on returns to labour. Although about half the farmers claimed that hedges improved crop yields, after 3 years of experimentation, only about a fifth planted additional hedges and only14% did so to improve soil fertility. It thus appears that the potential for its adoption as a soil fertility practice in this area is low. Hedgerow intercropping appears to have greater adoption potential if its aim is to provide feed for an intensive dairy operation or for curbing soil erosion. Control plots were of little use as farmers were more interested in contrasting test-plot yields with past yields than comparing the test and control plots. Different types of trials may be required to obtain reliable biophysical data on yield response and socioeconomic data on farmer assessment of complex agroforestry technologies.

---

• View source