Abstract: Studies on the autointoxication of Chinese fir show that the aqueous extracts of surface soil, leaf litter, half decaying leaf litter, fresh leaf, branch, bark and root in pure Chinese fir plantation and their polyvinyl pyrrolidone k30 (PVP) solutions affected the seed germination of Chinese fir, Raphanus sativous and water convolvulus. At high concentration of aqueous extracts, seed germination was significantly inhibited, while with decreasing concentration, the inhibitory effects got weaker, disappeared and even turned into stimulating effects. The aqueous extracts added PVPsignificantly weakened the inhibitory effect, and exhibited enhancement effect at low concentration.

Key words: Chinese fir, Autointoxication, Germination experiment, cotton, sowing date, yield, uptake and utilization of nutrient, fiber quality, Inner Mongolia west desert area