Abstract: A filed experiment was conducted with 6 levels of compost treatments including N0（0 kg·hm-2）， N1（35 640 kg·hm-2）， N2（47 520 kg·hm-2）， N3（59 400 kg·hm-2）， N4（71 280 kg·hm-2）and N5（95 040 kg·hm-2）， and one conventional fertilizer treatment （N6）. The purpose of this experiment was to investigate the optimized compost application rate in potato production system in Bashang area based on the disease incidence， yields and quality of potatoes and the contents of residual nitrate and available phosphorus in soils. It was shown that the disease incidences were relatively lower in N2， N3 and N4 treatment， and the greatest yield was harvested under N4 treatment. Among all the seven treatments， potatoes under N3 treatment exhibited the highest contents of starch， crude protein and vitamin C. The concentrations of residual nitrate in 0～20 cm soil layers of N0， N1, N2 and N3 were around 1403～1516 mg·kg-1， which were significantly （P<005） lower than that of N4， N5 and N6 treatments. Thus， it could be concluded that application of 59 400 kg·hm-2 compost was proper for sustaining soil fertility， reducing environmental risk and acquiring high economic benefit.

Key words: Bashang area, compost, potato, potato quality, soil fertility, soil environment