Soil Organic Carbon Stock and Crop Yields in Huang-Huai-Hai Plains, China

Abstract

The Huang-Huai-Hai-plains (HHH) is the main wheat ( Triticum aestivum)-maize( Zea mays) production area of China. Therefore, adoption of appropriate fertilizer management strategies of improving soil organic carbon (SOC) and crop yields is an important option in HHH. These studies included a total of 6 land use and management treatments including: (i) no fertilizer(CK); (ii) chemical nitrogen(N), phosphorus(P) and potassium(K) fertilizers separately(UF); (?) combined application of chemical fertilizer N,P and K(CF); (?) wheat and maize straw retention or manures including that from soybean ( Glycine max) cake, chicken, horse and cow dung or manures only (O); (?) combined application N, P and K and organic fertilizers (CFO); (?) combined application of chemical fertilizer N,P or K separately and organic fertilizers (UFO). The data indicated the following: (i) The baseline SOC stock of arable land was 18.9±1.8 Mg ha ^-1 and the corresponding crop yield was 4.4±1.5 Mg ha ^-1; the highest SOC stock was 24.6±1.8 Mg ha ^-1 for CFO and the corresponding crop yield was 9.7±3.2 Mg ha ^-1; (ii) The rate of increase of SOC stock was in the order of CFO>UFO>CF>O>UF, while that of increase in crop yield was in the order of CFO>CF>UFO>UF>O; (?) Crop yield increased (Mg ha ^-1 yr ^-1) by 0.114 in UF and CF, by 0.039 in treatment O,CFO and UFO, and by 0.033 in CK by increase in SOC stock by 1 Mg ha ^-1; (?) Yield increased (Mg ha ^-1 yr ^-1) by 0.298, 0.119,0.065, and 0.022 by over 5, 10, 15, and over 25 years by increase in SOC stock by 1 Mg ha ^-1. Therefore, the combined application of chemical and organic fertilizers is the best choice for the developing countries to adapt to and mitigate climate change while advancing food security.