Affiliations: Institute of Resources, Ecosystem and Environment of
Agriculture, Nanjing Agricultural University, Nanjing 210095, China | Extension Center of Soil and Fertilizer Technology,
Department of Agriculture, Jiangsu Administration, Nanjing 210000, China | Extension Center of Soil and Fertilizer Technology,
Donghai 222300, China | Extension Center of Soil and Fertilizer Technology,
Wujiang 215200, China | Extension Center of Soil and Fertilizer Technology,
Yixing 214200, China
Abstract: Data collection of soil organic carbon (SOC) of 154 soil series of
Jiangsu, China from the second provincial soil survey and of recent changes in
SOC from a number of field pilot experiments across the province were
collected. Statistical analysis of SOC contents and soil properties related to
organic carbon storage were performed. The provincial total topsoil SOC stock
was estimated to be 0.1 Pg with an extended pool of 0.4 Pg taking soil depth of
1 m, being relatively small compared to its total land area of 101700
km^2. One quarter of this topsoil stock was found in the
soils of the Taihu Lake region that occupied 1/6 of the provincial arable area.
Paddy soils accounted for over 50% of this stock in terms of SOC distribution
among the soil types in the province. Experimental data from experimental farms
widely distributed in the province showed that SOC storage increased
consistently over the last 20 years despite a previously reported decreasing
tendency during the period between 1950–1970. The evidence indicated that
agricultural management practices such as irrigation, straw return and rotation
of upland crops with rice or wheat crops contributed significantly to the
increase in SOC storage. The annual carbon sequestration rate in the soils was
in the range of 0.3–3.5 tC/(hm^2·a), depending on
cropping systems and other agricultural practices. Thus, the agricultural
production in the province, despite the high input, could serve as one of the
practical methods to mitigate the increasing air CO_2.
