Effects of enhancing soil organic carbon sequestration in the topsoil by fertilization on crop productivity and stability: Evidence from long-term experiments with wheat-maize cropping systems in China.
Although organic carbon sequestration in agricultural soils has been recommended as a 'win-win strategy' for mitigating climate change and ensuring food security, great uncertainty still remains in identifying the relationships between soil organic carbon (SOC) sequestration and crop productivity. Using data from 17 long-term experiments in China we determined the effects of fertilization strategies on SOC stocks at 0-20cm depth in the North, North East, North West and South. The impacts of changes in topsoil SOC stocks on the yield and yield stability of winter wheat (Triticum aestivum L.) and maize (Zea mays L.) were determined. Results showed that application of inorganic fertilizers (NPK) plus animal manure over 20-30years significantly increased SOC stocks to 20-cm depth by 32-87% whilst NPK plus wheat/maize straw application increased it by 26-38% compared to controls. The efficiency of SOC sequestration differed between regions with 7.4-13.1% of annual C input into the topsoil being retained as SOC over the study periods. In the northern regions, application of manure had little additional effect on yield compared to NPK over a wide range of topsoil SOC stocks (18->50MgCha(-1)). In the South, average yield from manure applied treatments was 2.5 times greater than that from NPK treatments. Moreover, the yield with NPK plus manure increased until SOC stocks (20-cm depth) increased to ~35MgCha(-1). In the northern regions, yield stability was not increased by application of NPK plus manure compared to NPK, whereas in the South there was a significant improvement. We conclude that manure application and straw incorporation could potentially lead to SOC sequestration in topsoil in China, but beneficial effects of this increase in SOC stocks to 20-cm depth on crop yield and yield stability may only be achieved in the South.
Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China; Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, UK; Key Laboratory of Ecosystem Network Observation and Modeling, Yucheng Comprehensive Experiment Station, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Xubo
X
Zhang
Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: sunnan@caas.cn.
Nan
N
Sun
Sustainable Soils and Grassland Systems Department, Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, UK.
Lianhai
L
Wu
Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China. Electronic address: xuminggang@caas.cn.
Minggang
M
Xu
Crop & Soil Systems Research, SRUC, Kings Buildings, West Mains Rd., Edinburgh EH9 3JG, UK.
Ian J
IJ
Bingham
Chemistry and Bioengineering College, Hezhou University, Hezhou 542899, China.
Zhongfang
Z
Li
D000383:Agriculture / Q000379:methods*; D002244:Carbon / Q000032:analysis; D057965:Carbon Sequestration; D002681:China; D018556:Crops, Agricultural / Q000378:metabolism; D005308:Fertilizers; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012987:Soil / Q000737:chemistry; D014908:Triticum / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism
D005308:Fertilizers; D012987:Soil; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen
China; Manure application; Soil organic carbon; Straw return; Yield; Yield stability