Changes in soil carbon and nitrogen foll
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Author's personal copy
Agriculture, Ecosystems and Environment 169 (2013) 12–20
Contents lists available at SciVerse ScienceDirect
Agriculture, Ecosystems and Environment
journal homepage: www.elsevier.com/locate/agee
Changes in soil carbon and nitrogen following tillage conversion in a
long-term experiment in Northern France
Bassem Dimassi a , Jean-Pierrre Cohan b , Jerome Labreuche b , Bruno Mary a,∗
a
b
INRA, Unité Agro-Impact, Site de Laon, Pôle du Griffon, 02000 Barenton-Bugny, France
ARVALIS Institut du Végétal, Station Expérimentale, 91720 Boigneville, France
a r t i c l e
i n f o
Article history:
Received 28 September 2012
Received in revised form 17 January 2013
Accepted 23 January 2013
Keywords:
Soil organic carbon
SOC
Soil nitrogen
Long-term
Tillage
No till
Full inversion tillage
a b s t r a c t
Although continuous no-till (NT) is recommended for erosion control and carbon sequestration, it often
has a limited duration since farmers alternate between NT and full inversion tillage (FIT) to control weed
infestation and avoid soil compaction. In this paper, we evaluate the effect of continuous tillage and tillage
conversion of NT to FIT and vice versa on SOC and SON stocks, in a long-term experiment at Boigneville in
Northern France. Continuous NT (CNT) and FIT (CFIT) treatments were established in 1991 and maintained
until 2011 while half of the plots were converted in 2005: from CNT to new FIT (NFIT) and CFIT to new
NT (NNT). Bulk densities and organic C and N contents were determined in 2001 and 2011 down to the
old ploughing depth (opd) which was also measured. SOC and SON stocks were calculated at equivalent
soil mass by correcting either bulk densities or the opd. Both methods produced very close results and
similar conclusions.
A typical gradient of SOC and SON concentrations vs depth was observed in CNT as opposed to a rather
uniform distribution in CFIT. CNT resulted in SOC concentration in the top soil (0–5 cm) higher by 38%
in 2001 and 53% in 2011 compared to CFIT. Conversely, it led to a SOC reduction in the deeper layer
(ca. 10–28 cm) by 14% in 2001 and 18% in 2011. The global effect was no significant change in SOC and
SON stocks between treatments over the old ploughed layer (4060 t soil ha−1 ) in both years: 43.2 and
45.0 t C ha−1 in 2001 and 44.7 and 45.8 t C ha−1 in 2011, in CNT and CFIT, respectively.
In 2011, six years after tillage conversion, the stratification of SOC and SON had disappeared in NFIT
whereas a new one had appeared in NNT with a smaller gradient than in CNT. SOC or SON stocks over
the old ploughed layer did not differ significantly between treatments after 6 years of conversion: SOC
stocks were 45.8, 43.2, 44.7 and 43.1 t C ha−1 in the CFIT, NFIT, CNT and NNT treatments, respectively.
Furthermore, SOC stocks below the old ploughed layer (ca. 28–40 cm) were slightly greater in FIT than in
NT treatment (10.9 vs 8.7 t C ha−1 ). In this experiment, continuous or conversion tillage did not result in
any C sequestration benefit.
© 2013 Elsevier B.V. All rights reserved.
1. Introduction
The adoption of conservation tillage practices including notill technique (NT) has considerably increased during the last
decades. Derpsch and Friedrich (2009) reported that agricultural
areas under NT progressed worldwide from 45 million ha in
1999 to 105 million ha in 2008. In 2006, 34% of annual crops in
France had been established without prior soil inversion against
21% five years earlier (Chapelle-Barry, 2008). Currently in Europe,
there are about 1.3 million ha of arable cropland under ‘conservation agriculture systems’ involving no till or shallow tillage
without soil inversion (ECAF, 2011). This interest for NT techniques may be explained by several expected benefits such as
∗ Corresponding author. Tel.: +33 3 23 24 07 71; fax: +33 3 23 24 07 76.
E-mail address: bruno.mary@laon.inra.fr (B. Mary).
0167-8809/$ – see front matter © 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.agee.2013.01.012
soil and water conservation, enhancement of soil fertility (Liebig
et al., 2004; Melero et al., 2009), reduction of tillage costs, working time and fuel consumption which remain the major motivation
for farmers. Comparing the energy requirements of no-till, minimum tillage (MT) and full inversion tillage (FIT), Sharma et al.
(2011) found that NT and MT decreased the energy consumption
by 34% and 31%, respectively, compared to FIT. However, longterm continuous NT is restricted in practice and farmers often
alternate between NT and mouldboard ploughing (Pierce et al.,
1994). A study conducted by Hill (2001) in the Corn Belt of the
United States indicated that the average duration of NT did not
exceed 1.4 and 2.4 years in Minnesota and Illinois, respectively.
Rotational tillage is applied on about 40% of agricultural fields
in Indiana (Omonode et al., 2006). In France, only 11% of annual
crops that were conducted without prior soil inversion in 2006
had never been mouldboard ploughed since 2001 (Chapelle-Barry,
2008).
Author's personal copy
B. Dimassi et al. / Agriculture, Ecosystems and Environment 169 (2013) 12–20
Several terms are used in the literature to describe this tillage
management: intermittent, infrequent, periodically or occasional
FIT (Conant et al., 2007; Quincke et al., 2007). Periodic tillage may
help to solve the problems linked to conservation tillage and NT
techniques such as pathogens development or infestation of herbicide resistant weeds that may compromise crop production and/or
increase pesticides use (Chapelle-Barry, 2008). It is encouraged in
Europe by the directive 2009/128/CE on the sustainable use of pesticides. A long-term survey carried out in Nebraska, USA showed that
FIT (mouldboard ploughing) decreased the population of downy
brome weeds in comparison with undisturbed NT (Kettler et al.,
2000). Reduced tillage without inversion seems to be more promising than FIT but has some drawbacks. For example, Sans et al. (2011)
showed that reduced tillage using chisel plough increased by two to
three times total weed cover and perennial cover compared to full
inversion tillage. Another interest of periodic FIT may be the reduction of soil compaction. Ferreras et al. (2000) examined physical
properties of a Chernozemic loam soil with degraded structure in
Argentina, found higher soil mechanical resistance under NT compared to FIT and suggested that this might lead to smaller growth
of wheat roots and reduce wheat yield.
A large number of studies have assessed the impact of conversion from FIT to NT on soil organic carbon (SOC) and nitrogen
(SON) (e.g. Deen and Kataki, 2003; Hermle et al., 2008; BlancoCanqui and Lal, 2008; Christopher et al., 2009; Dalal et al., 2011)
as well as recent meta-analyses (Baker et al., 2007; Angers and
Eriksen-Hamel, 2008; Luo et al., 2010; Virto et al., 2011). However few studies have investigated the impact of occasional FIT or
complete re-conversion of NT to FIT on SOC and SON (Pierce et al.,
1994; Quincke et al., 2007; Conant et al., 2007; Yang et al., 2008).
These studies show a marked redistribution of SOC within the soil
profile after conversion from NT to FIT by mouldboard ploughing
and a large variability in the results of stock evolution between
experiments. In this paper, we analyze the results of a long-term
experiment (20 years) comparing NT and FIT. Our objectives were
(1) to compare two methods of calculation of SOC and SON stocks,
(2) to quantify the impact of 20 years of continuous FIT or NT on
SOC and SON distribution and stocks and (3) to analyze the evolution of SOC and SON stocks after 6 years of conversion of NT to FIT
and vice versa.
2. Materials and methods
2.1. Study site and experimental design
The ongoing long-term field experiment is carried out
by Arvalis-Institut du Végétal at the experimental station of
Boigneville, Northern France on a Haplic Luvisol, (FAO, 1998)
developed on loess. It is referred as Experiment E (48◦ 19′ 30′′ N,
2◦ 23′ 03′′ E). Physical and chemical soil characteristics are shown
at Table 1. The site has an average annual temperature and precipitation of 10.8 ◦ C and 650 mm, respectively (Constantin et al.,
2012). The field had been mouldboard ploughed for many years
and was ploughed down to about 28 cm until 1991 when the
experiment was initiated. Two tillage treatments were established
and maintained until 2011: CFIT (continuous full inversion tillage)
and CNT (continuous no-till). After 1991, mouldboard ploughing
in CFIT was realized every year to a smaller depth (about 25 cm)
than before while the only tillage operation in the CNT treatment
was sowing using a drill equipped with discs. The tillage operations in CFIT treatment were: shallow cultivation with disc harrow
two times after harvest, mouldboard ploughing in autumn and
seedbed preparation at sowing. Crop residues were all returned
to soil, either mixed with soil by tillage in CFIT or left at soil surface in the CNT treatment. The experimental design is a randomized
13
Table 1
Soil characteristics measured in 2001 in the 0–25 cm soil layer in the two treatments:
CFIT = continuous full inversion tillage; CNT = continuous no till.
Clay (
copy is furnished to the author for internal non-commercial research
and education use, including for instruction at the authors institution
and sharing with colleagues.
Other uses, including reproduction and distribution, or selling or
licensing copies, or posting to personal, institutional or third party
websites are prohibited.
In most cases authors are permitted to post their version of the
article (e.g. in Word or Tex form) to their personal website or
institutional repository. Authors requiring further information
regarding Elsevier’s archiving and manuscript policies are
encouraged to visit:
http://www.elsevier.com/authorsrights
Author's personal copy
Agriculture, Ecosystems and Environment 169 (2013) 12–20
Contents lists available at SciVerse ScienceDirect
Agriculture, Ecosystems and Environment
journal homepage: www.elsevier.com/locate/agee
Changes in soil carbon and nitrogen following tillage conversion in a
long-term experiment in Northern France
Bassem Dimassi a , Jean-Pierrre Cohan b , Jerome Labreuche b , Bruno Mary a,∗
a
b
INRA, Unité Agro-Impact, Site de Laon, Pôle du Griffon, 02000 Barenton-Bugny, France
ARVALIS Institut du Végétal, Station Expérimentale, 91720 Boigneville, France
a r t i c l e
i n f o
Article history:
Received 28 September 2012
Received in revised form 17 January 2013
Accepted 23 January 2013
Keywords:
Soil organic carbon
SOC
Soil nitrogen
Long-term
Tillage
No till
Full inversion tillage
a b s t r a c t
Although continuous no-till (NT) is recommended for erosion control and carbon sequestration, it often
has a limited duration since farmers alternate between NT and full inversion tillage (FIT) to control weed
infestation and avoid soil compaction. In this paper, we evaluate the effect of continuous tillage and tillage
conversion of NT to FIT and vice versa on SOC and SON stocks, in a long-term experiment at Boigneville in
Northern France. Continuous NT (CNT) and FIT (CFIT) treatments were established in 1991 and maintained
until 2011 while half of the plots were converted in 2005: from CNT to new FIT (NFIT) and CFIT to new
NT (NNT). Bulk densities and organic C and N contents were determined in 2001 and 2011 down to the
old ploughing depth (opd) which was also measured. SOC and SON stocks were calculated at equivalent
soil mass by correcting either bulk densities or the opd. Both methods produced very close results and
similar conclusions.
A typical gradient of SOC and SON concentrations vs depth was observed in CNT as opposed to a rather
uniform distribution in CFIT. CNT resulted in SOC concentration in the top soil (0–5 cm) higher by 38%
in 2001 and 53% in 2011 compared to CFIT. Conversely, it led to a SOC reduction in the deeper layer
(ca. 10–28 cm) by 14% in 2001 and 18% in 2011. The global effect was no significant change in SOC and
SON stocks between treatments over the old ploughed layer (4060 t soil ha−1 ) in both years: 43.2 and
45.0 t C ha−1 in 2001 and 44.7 and 45.8 t C ha−1 in 2011, in CNT and CFIT, respectively.
In 2011, six years after tillage conversion, the stratification of SOC and SON had disappeared in NFIT
whereas a new one had appeared in NNT with a smaller gradient than in CNT. SOC or SON stocks over
the old ploughed layer did not differ significantly between treatments after 6 years of conversion: SOC
stocks were 45.8, 43.2, 44.7 and 43.1 t C ha−1 in the CFIT, NFIT, CNT and NNT treatments, respectively.
Furthermore, SOC stocks below the old ploughed layer (ca. 28–40 cm) were slightly greater in FIT than in
NT treatment (10.9 vs 8.7 t C ha−1 ). In this experiment, continuous or conversion tillage did not result in
any C sequestration benefit.
© 2013 Elsevier B.V. All rights reserved.
1. Introduction
The adoption of conservation tillage practices including notill technique (NT) has considerably increased during the last
decades. Derpsch and Friedrich (2009) reported that agricultural
areas under NT progressed worldwide from 45 million ha in
1999 to 105 million ha in 2008. In 2006, 34% of annual crops in
France had been established without prior soil inversion against
21% five years earlier (Chapelle-Barry, 2008). Currently in Europe,
there are about 1.3 million ha of arable cropland under ‘conservation agriculture systems’ involving no till or shallow tillage
without soil inversion (ECAF, 2011). This interest for NT techniques may be explained by several expected benefits such as
∗ Corresponding author. Tel.: +33 3 23 24 07 71; fax: +33 3 23 24 07 76.
E-mail address: bruno.mary@laon.inra.fr (B. Mary).
0167-8809/$ – see front matter © 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.agee.2013.01.012
soil and water conservation, enhancement of soil fertility (Liebig
et al., 2004; Melero et al., 2009), reduction of tillage costs, working time and fuel consumption which remain the major motivation
for farmers. Comparing the energy requirements of no-till, minimum tillage (MT) and full inversion tillage (FIT), Sharma et al.
(2011) found that NT and MT decreased the energy consumption
by 34% and 31%, respectively, compared to FIT. However, longterm continuous NT is restricted in practice and farmers often
alternate between NT and mouldboard ploughing (Pierce et al.,
1994). A study conducted by Hill (2001) in the Corn Belt of the
United States indicated that the average duration of NT did not
exceed 1.4 and 2.4 years in Minnesota and Illinois, respectively.
Rotational tillage is applied on about 40% of agricultural fields
in Indiana (Omonode et al., 2006). In France, only 11% of annual
crops that were conducted without prior soil inversion in 2006
had never been mouldboard ploughed since 2001 (Chapelle-Barry,
2008).
Author's personal copy
B. Dimassi et al. / Agriculture, Ecosystems and Environment 169 (2013) 12–20
Several terms are used in the literature to describe this tillage
management: intermittent, infrequent, periodically or occasional
FIT (Conant et al., 2007; Quincke et al., 2007). Periodic tillage may
help to solve the problems linked to conservation tillage and NT
techniques such as pathogens development or infestation of herbicide resistant weeds that may compromise crop production and/or
increase pesticides use (Chapelle-Barry, 2008). It is encouraged in
Europe by the directive 2009/128/CE on the sustainable use of pesticides. A long-term survey carried out in Nebraska, USA showed that
FIT (mouldboard ploughing) decreased the population of downy
brome weeds in comparison with undisturbed NT (Kettler et al.,
2000). Reduced tillage without inversion seems to be more promising than FIT but has some drawbacks. For example, Sans et al. (2011)
showed that reduced tillage using chisel plough increased by two to
three times total weed cover and perennial cover compared to full
inversion tillage. Another interest of periodic FIT may be the reduction of soil compaction. Ferreras et al. (2000) examined physical
properties of a Chernozemic loam soil with degraded structure in
Argentina, found higher soil mechanical resistance under NT compared to FIT and suggested that this might lead to smaller growth
of wheat roots and reduce wheat yield.
A large number of studies have assessed the impact of conversion from FIT to NT on soil organic carbon (SOC) and nitrogen
(SON) (e.g. Deen and Kataki, 2003; Hermle et al., 2008; BlancoCanqui and Lal, 2008; Christopher et al., 2009; Dalal et al., 2011)
as well as recent meta-analyses (Baker et al., 2007; Angers and
Eriksen-Hamel, 2008; Luo et al., 2010; Virto et al., 2011). However few studies have investigated the impact of occasional FIT or
complete re-conversion of NT to FIT on SOC and SON (Pierce et al.,
1994; Quincke et al., 2007; Conant et al., 2007; Yang et al., 2008).
These studies show a marked redistribution of SOC within the soil
profile after conversion from NT to FIT by mouldboard ploughing
and a large variability in the results of stock evolution between
experiments. In this paper, we analyze the results of a long-term
experiment (20 years) comparing NT and FIT. Our objectives were
(1) to compare two methods of calculation of SOC and SON stocks,
(2) to quantify the impact of 20 years of continuous FIT or NT on
SOC and SON distribution and stocks and (3) to analyze the evolution of SOC and SON stocks after 6 years of conversion of NT to FIT
and vice versa.
2. Materials and methods
2.1. Study site and experimental design
The ongoing long-term field experiment is carried out
by Arvalis-Institut du Végétal at the experimental station of
Boigneville, Northern France on a Haplic Luvisol, (FAO, 1998)
developed on loess. It is referred as Experiment E (48◦ 19′ 30′′ N,
2◦ 23′ 03′′ E). Physical and chemical soil characteristics are shown
at Table 1. The site has an average annual temperature and precipitation of 10.8 ◦ C and 650 mm, respectively (Constantin et al.,
2012). The field had been mouldboard ploughed for many years
and was ploughed down to about 28 cm until 1991 when the
experiment was initiated. Two tillage treatments were established
and maintained until 2011: CFIT (continuous full inversion tillage)
and CNT (continuous no-till). After 1991, mouldboard ploughing
in CFIT was realized every year to a smaller depth (about 25 cm)
than before while the only tillage operation in the CNT treatment
was sowing using a drill equipped with discs. The tillage operations in CFIT treatment were: shallow cultivation with disc harrow
two times after harvest, mouldboard ploughing in autumn and
seedbed preparation at sowing. Crop residues were all returned
to soil, either mixed with soil by tillage in CFIT or left at soil surface in the CNT treatment. The experimental design is a randomized
13
Table 1
Soil characteristics measured in 2001 in the 0–25 cm soil layer in the two treatments:
CFIT = continuous full inversion tillage; CNT = continuous no till.
Clay (