Abstract: By using 1∶200 000 soil database, the soil organic carbon storage in Henan Province was estimated, and its spatial distribution was analyzed. The results showed that in this province, soil organic carbon storage was about 10.27×10⁸ t, accounting for 1.15% of the total in China, and its density was 7.46 kg·m^-2 on average, being lower than that (9.60 kg·m^-2) in this country. The top four soil types in organic carbon storage were fluvo-aquic soil, cinnamon soil, skeletal soil, and yellow cinnamon soil, with the storage all being higher than 1.0×10⁸ t and totally taken up 69.65% of that in Henan. The organic carbon density was the highest in bog soil (24.54 kg·m^-2), followed by in mountain meadow soil (17.69 kg·m^-2) and brown soil (14.64 kg·m^-2). These three soil types mainly distributed in the mountainous areas of west Henan, and the sum of their organic carbon storage was only accounted for 6.34% of the total in the province. The organic carbon density was the lowest in rocky soil (1.32 kg·m^-2) and aeolian sandy soil (1.38 kg·m^-2). In general, the density of soil organic carbon in Henan Province mostly varied from 5 kg·m^-2 to 10 kg·m^-2.

Key words: cotton, soil enzyme, organic fertilizer, soil microorganism