Abstract: This paper discusses several problems existed in dryland-ecosystem of Din gxi district and their occurence.It's considered that the main problems are lower and unstable crop yields,serious water-and soil erosion and deficiency of fertilizer,forage and fuel.Their occurence is due to the unreasonable structure of agriculture,low utilization rate of natural resources and unbalance of material and energy flow in this ecosystem.Some corresponding countermeasures are put forward by the author.

Key words: Modified ammonium bicarbonate, DCD, Nitrification and denitrification, NO and N₂O emission