Soil carbon under perennial pastures; benchmarking the influence of pasture age and management

Soil Change Matters 2014

Orgill, Susan E.^1 ; Spoljaric, Nancy^2 ; Kelly, Georgina^3

NSW Department of Primary Industries, Wagga Wagga Agricultural Institute, NSW

2650, Australia^1

Monaro Farming Systems, PO Box 27, Bombala

NSW

2632, Australia^2

NSW Department of Primary Industries, 470 Church St, North Parramatta

2151, Australia^3

关键词: Annual rainfall;    Cropping history;    Land managements;    Nutrient management;    Parent materials;    Perennial pastures;    Soil carbon sequestration;    Soil carbon stock;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/25/1/012018/pdf
DOI  :  10.1088/1755-1315/25/1/012018

来源: IOP

【 摘 要 】

This paper reports baseline soil carbon stocks from a field survey of 19 sites; 8 pairs/triplet in the Monaro region of New South Wales. Site comparisons were selected by the Monaro Farming Systems group to demonstrate the influence of land management on soil carbon, and included: nutrient management, liming, pasture age and cropping history. Soil carbon stocks varied with parent material and with land management. The fertilised (phosphorus) native perennial pasture had a greater stock of soil carbon compared with the unfertilised site; 46.8 vs 40.4 Mg.C.ha to 0.50 m. However, the introduced perennial pasture which had been limed had a lower stock of soil carbon compared with the unlimed site; 62.8 vs 66.7 Mg.C.ha to 0.50 m. There was a greater stock of soil carbon under two of the three younger (35 yr old) pastures. Cropped sites did not have lower soil carbon stocks at all sites; however, this survey was conducted after three years of above average annual rainfall and most sites had been cropped for less than three years. At all sites more than 20% of the total carbon stock to 0.50 m was in the 0.30 to 0.50 m soil layer highlighting the importance of considering this soil layer when investigating the implications of land management on soil carbon. Our baseline data indicates that nutrient management may increase soil carbon under perennial pastures and highlights the importance of perennial pastures for soil carbon sequestration regardless of age.