
TY  - JOUR
A1  - Parfitt, R. L. 
A1  - Parshotam, A. 
A1  - Salt, G. J. 
T1  - Carbon turnover in two soils with contrasting mineralogy under long-term maize and pasture
JF  - Soil Research
JO  - Soil Res.
Y1  - 2002
VL  - 40
IS  - 1
SP  - 127
EP  - 136
KW  - clover, grass, New Zealand soils.
UR  - https://doi.org/10.1071/SR00105 
N2  - Total organic carbon (C) and natural 13C abundance were measured in adjacent allophanic soils (Andisols) and non-allophanic soils (Inceptisols) under maize (Zea mays L.) and ryegrass pasture (Lolium perenne L.) to assess the C turnover rate in soils of contrasting mineralogy and specific surface area. The allophanic soil contained more total C than the non-allophanic soil (139 v. 101 t C&sol;ha in the upper 0&#8211;35 cm) but neither soil showed a significant difference in C content between pasture and maize, provided maize residue was retained and incorporated. The gross annual inputs under maize and pasture were both estimated to be about 9 t C&sol;ha, consistent with the similar soil total C contents. Since the soil total C content did not appear to change with time, the gross C mineralisation was about 9 t C&sol;ha each year. The proportion of old pasture C remaining in the soil after maize cropping for 25 years was about 78&percnt; in the allophanic soils and about 69&percnt; in the non-allophanic soils, reflecting the influence of both Al and allophane, with its high specific surface area, on the retention of old C. The maize C retained in 25 years was similar in both the allophanic soil and the non-allophanic soil (29 t&sol;ha). Therefore, the higher total C content of the allophanic soil would appear to arise from stabilisation of old pasture and forest C by Al and allophane. clover, grass, New Zealand soils. 
ER  -

