Issue |
Agron. Sustain. Dev.
Volume 29, Number 4, October-December 2009
|
|
---|---|---|
Page(s) | 525 - 533 | |
DOI | https://doi.org/10.1051/agro/2009024 | |
Published online | 02 October 2009 |
DOI: 10.1051/agro/2009024
Effect of tillage system and straw management on organic matter dynamics
Samarendra Hazarika1, Robert Parkinson2, Roland Bol3, Liz Dixon3, Peter Russell2, Sarah Donovan2 and Debbie Allen41 Dept. of Agricultural Engineering, Assam Agricultural University, Jorhat-785 013, Assam, India
2 School of Biological Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK
3 Soil and Water team, Cross Institute Programme for Sustainable Soil Function, North Wyke Research, Okehampton, Devon EX20 2SB, UK
4 Plant Genetics and Breeding, Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, SY23 3EB, UK
Accepted 6 July 2009 ; published online 2 October 2009
Abstract - The choice of cultivation system in arable agriculture exerts a strong influence
not only on soil health and crop productivity but also on the wider
environment. Conservation tillage using non-inversion methods conserves soil
carbon, reduces erosion risk and enhances soil quality. In addition,
conservation tillage has been shown to sequester more carbon within the soil
than inversion tillage, reducing carbon dioxide losses to the atmosphere.
Stable, well structured topsoils that develop following long-term
conservation tillage lead to more energy efficient systems due to the
reduced power requirements for cultivation. Long-term experiments, e.g. more
than 20 years, that confirm the impact of conservation tillage over an
extended period are not common. Here we evaluate the impact of different
tillage methods and winter wheat straw management, either incorporated or
removed, on organic matter turnover and soil quality indicators. No-till,
chisel and mouldboard ploughing was carried out for 23 years on a silty clay
loam soil in South West England that was not considered suitable for
non-inversion tillage due to weak soil structure. In order to assess the
effect of contrasting cultivation and straw disposal method on soil carbon
dynamics, a range of assays were conducted, including water extractable
organic carbon, hot water extractable carbohydrate, microbial biomass
carbon, activity of -glucosidase and acid phosphatase enzymes, C
sequestration and the natural abundance of 13C. Our results show that
the soil organic carbon concentration in the topsoil was greater under
no-till than mouldboard ploughing, while a reverse trend was observed in the
lower depths. A 14–17% increase in soil organic carbon was observed in
the topsoil for chisel plough and no-till treatments compared to mouldboard
ploughing. Water extractable organic carbon was found to constitute only
1–7% of the microbial biomass carbon. Hot water extractable carbohydrate
was one of the most sensitive indicators of soil quality and had a
significant a negative correlation with bulk density and positive
correlation with soil organic carbon microbial biomass carbon
-glucosidase and acid phosphatase. The choice of cultivation method exerted
a major control on microbial and carbon dynamics. No-till and chisel
ploughing maintained carbon in the soil surface horizons, which will benefit
the stability of this weakly structured soil, but mouldboard ploughing
distributed carbon more uniformly throughout the soil profile, particularly
when straw was incorporated, hence leading to the retention of more carbon
in the soil profile.
Key words: soil quality / carbon sequestration / tillage / straw management / winter wheat
Corresponding author: rparkinson@plym.ac.uk
© INRA, EDP Sciences 2009