SUSTAINABILITY OF SLOPING LAND CULTIVATION SYSTEMS IN THE MID-HILLS OF NEPAL

Maintenance of soil resources is critical in the middle hills of Nepal where the majority of the population are engaged in small-scale agriculture. However, the causes of declines in soil fertility are complex and related to social change, meaning that farmers are unlikely to adopt soil conservation measures if that is their sole function. In several districts of the middle hills. large, steeply sloping terraces are predominant, so constructed because terrace size is perceived as reflecting wealth and status. They contrast sharply with the flat. narrow terraces characteristic of most middle hill areas. Thus, soil and water management is particularly challenging. This research investigated the efficacy of a combination of legumes, mulch and strip crops in controllina nutrient losses in surface runoffand leachate. Losses of nutrients in leachate exceeded those in runoff by an order of 202 (N), 45 (P) and 27 (K) despite the steep slopes. There was evidence of nutrient scouring associated with soil movement downslope. Income was increased Lip to threefold as a result of incorporating strips of ginger (Zingiber officinale Rosc.) in the maize-based systems. The results indicate that low-input, strip crop technologies are effective in soil and water conservation through the sieve-barrier effect, while increasing farmers' income and hence have the potential to maintain the overall sustainability of this land-use system. Copyright (c) 2008 John Wiley & Sons, Ltd.