Challenges for research and development on improving shifting cultivation systems

one of vthe issues that is raised periodicallyis discussions concerning care tor the environment is the role of traditional agricultural systems, and in particular shifting caltivation (known lecaly as jhum)and the treat it poses to sustainability, particularly of forest. in the light of resent concerns about climate change and the role of forest as carbon sinks, these discussions are becoming extremely relevant. As a result, the traditonal agricultural system of jhum often comes under attack .it is a fact that the majorproblem created by jhum is erosion of top soil.Without any conservation measures ,the loss of top soil in jhum-caltivation area is about 30.62 metric tones/ha/year in the first year of cropping and 30mt/ha in the second year(SARS-NEPED.1998).when measures are employed to conserve the soil, the loss is reduced to 11.37and 13.38mt/ha/yr in the first and second years respectively.Another major problem is rain water run off from the ssface of caltivated area.If one consideres that average annual rainfal is about 2000mm. one can imagine what propotion of rain water percolates into the soil i jhumarea and how much runs off.