Alternative Cropping Systems for North-West Cambodia

抄録

A field research program commenced in north-west (NW) Cambodia in 2012 to test the feasibility of including a dry season crop for this upland area, increasing the cropping intensity from 2 to 3 crops per year. Dual purpose crop options that can be harvested for fresh forage or silage in the event of crop failure due to drought will also be evaluated. Forest clearing after 1998 has been followed by the expansion of upland cropping in NW Cambodia. Major threats to sustainable agricultural production in the region are: (a) rapid soil degradation, soil fertility decline, loss of crop diversity; and (b) poverty and lack of income diversity for small-holder farmers. Access to improved agricultural technologies could provide solutions to these problems. Current farmer practice involves growing two crops per year, with an early wet season crop (March-June) and followed by a main wet season crop (July-October). Land is ploughed after the main wet season crop or left fallow from November to February. Due to high rainfall in NW Cambodia in September and October, there is significant residual water remaining in the soil after the wet season that could be exploited by crops rather than weeds as it currently is. The risk of growing dry season crops would be reduced if tillage was eliminated and surface crop residues were retained to conserve soil water. Small-holder farmers in NW Cambodia struggle to cover household expenses with crop income. Annual gross margins from growing two crops of maize (USD 874/ha) are declining and farmers are turning to cassava (USD 1,066/ha) to increase income and reduce labour costs. Replacing early wet season maize with peanut is more profitable (USD 1,447/ha); moreover adding dry season sunflower into the peanut-maize rotation to grow three crops per year could return a gross margin of USD 1,888/ha.