128 J. Fismes et al. European Journal of Agronomy 12 2000 127–141
This could be due to either important losses of in calcareous soils when S supply was above
30 kg ha−1, and an application of 60 kg S ha−1 sulfates by leaching during the winter, which can
reach 80 kg ha−1 Suhardi, 1992, or slow min- increased the GLS content by 20
. However, with the general widespread use of double O cultivars,
eralization hampered by both low spring temper- ature and alkaline nature of these soils Merrien,
reasonable levels of GLS can be achieved owing to the ability of these cultivars to store Zhao
1988. Nutritionally, oilseed rape and Brassica species
et al., 1993a and to regulate Fismes et al., 1999 the excess of S in pod walls. Based on these
in general require S during their growth Zhao et al., 1993a, for the synthesis of both protein
observations, sufficient S supply to maintain the optimum yield is required. For this purpose, ATS
and naturally occurring glucosinolates. Oilseed rape is thus particularly sensitive to S deficiency,
is gaining in use, because besides the inhibitory actions on N, it contains high S concentration
and in the last 10 years, significant yield responses to S application jointly with N have been achieved
Goos, 1985. In field studies, apart from maize Graziano
and Parente,
1996, bromegrass
Janzen and Bettany, 1984; Merrien, 1988; Zhao et al., 1993b; Withers and O’Donnel, 1994;
Lemond et al., 1995 and recently tall fescue Sweeney and Moyer, 1997, its extension to other
MacGrath and Zhao, 1996. In general, higher plants assimilate N and S in
crops such as rapeseed is scantily reported in the literature. On the other hand, there is a substantial
amounts proportional to that incorporated into amino acids and proteins, which suggests that N
body of information on plant N nutrition and the data related to both N and S are still very poor,
and S requirements are closely interrelated Rendig et al., 1976; Friedrich and Schrader, 1978.
at least for rapeseed. Accounting for the above observations, this work aimed to examine how
Increasing N fertilizer rates aggravate S deficiency of oilseed rape and reduce seed yield when avail-
increasing levels of S fertilization in such a calcare- ous soil could affect the efficiency of N utilization
able S is limiting Janzen and Bettany, 1984. A NS ratio value 16 in plant tissues indicates that
and thereby the yield and the quality of seed, in particular the GLS and oil content. It also gives
S is insufficient for protein formation in maize Cassel et al., 1996 and tall fescue Sweeney and
further information about the links which exist between N and S nutrition at the main stages of
Moyer, 1997 and the excess of unassimilated NO−
3 –N, amides or free amino acids accumulates
plant growth. Sexton et al., 1997. Conversely, N addition
increases seed yield in S-sufficient conditions, and an optimum oil quality and maximum yield
2. Materials and methods
responses to both N and S applications are obtained when the amounts of available N and S
2.1. Materials are balanced Joshi et al., 1998.
Several works have also shown that S supply The soil used in this study is the typic Rendolls
Rendzina, the most representative of Lorraine may increase glucosinolate GLS content of oil-
seed rape Janzen and Bettany, 1984; Merrien, soils for rapeseed crops. This soil contains 2.2
organic C, 0.28 organic N and 0.043
organic 1988; Schnug, 1991; Zhao et al., 1993b; Withers
and O’Donnel, 1994. Thus, if an insufficient S S. Its pH is alkaline pH water: 8. According to
Merrien 1987, this soil is high in organic-N and nutrition leads to a decline in seed yield, an
excessive S supply can affect meal quality by organic-S content.
increasing seed GLS content. Indeed, the glucosi- nolates are hydrolysed by the myrosinase enzyme
2.2. Experimental protocol upon seed processing to form undesirable tasting,
toxic and goitrogenic compounds Rosa and 2.2.1. Pot experiments
To ensure ‘baseline samples’ that were influ- Rodrigues, 1998. Merrien 1988 observed a sig-
nificant response of GLS content to S application enced as little as possible by the annual fluctuations
129 J. Fismes et al. European Journal of Agronomy 12 2000 127–141
due to seasonal peaks in C, N and S inputs, the 2.2.2. Field experiments
In 1995–96 and 1996–97, the winter rapeseed soil for pot experiments was sampled in late
cultivar Goeland was sown by CETIOM Centre January before it had been fertilized.
Technique Interprofessionnel
des Ole´agineux
In 1995, the air-dried and sieved soil was fertil- Me´tropolitains on August with a density of
ized with 200 kg N ha−1 as ammonium nitrate 65 g m−2 and 40 cm between rows. Prior to sowing,
AN , urea UR or cow slurry SL and with or a weeding with Trifuralin and a preventive treat-
without 75 kg S ha−1 as ammonium thiosulfate ment with Mercaptodimethur against slugs were
ATS . The weight of soil taken for the calcula- made. The level of sulfur as ATS was maintained
tions of the corresponding nutrient rates per pot at the normal dose of 30 kg ha−1 but comple-
was 2400 t ha−1 20 cm depth and 1.2 density. mented or not with MgSO
4 to keep the traditional
After bringing the soil moisture to 80 of WHC
dose of S practised in the region for oilseed rape, with the above fertilizer solutions or distilled water
the level of N being constant to 200 kg ha−1. The for the control, the soil was transferred into PVC
experiment consisted of nine treatments distributed pots which contained an equivalent of 1 kg dry
according to a complete randomized block design soil 105°C . Due to technical reasons, the experi-
with four replicates each. Each plot had 16.7 m 2,
ment with slurry was performed with the same soil but in order to minimize edge effects, the plants
but three months later. The experiment consisted were sampled in an area of 10 m
2. The annual of seven treatments with five replicates each. In
background fertilization of P and K were 35 and each pot, five seeds of cultivar Hybridol double
83 kg ha−1, respectively. N and S applications were O spring rapeseed were sown and after germina-
split into two fractions: 25 in March and the
tion, only one plant was kept until maturity. remainder about one month later. P, K and
During the plant growth, the pots were regularly MgSO
4 were applied with this second fraction. For
watered to maintain the soil moisture near to 80 reasons of efficiency, ATS was sprayed first onto
of WHC. At two-leaf stage, a preventive treatment the soil prior to N application.
by Flusilazol and Carbendazim against Sclerotinia 2.3. Plant sampling and chemical analysis
sclerotiorum and Erysiphe graminis was made. In 1996, two levels of S were used: 30 kg ha−1
Sequential plant samplings Table 1 were made as ATS, in order to comply with the economically
at three growth stages CETIOM, INRA, PV advised dose for ATS and 75 kg as ATS or
classification: at rosette stage, five open leaves MgSO
4 , to respond to the traditional S fertilization
B5; at flowering stage F2 and at seed maturity of oilseed rape. In addition, the cow slurry was
G5 under controlled conditions; and at green abandoned in the second year because it is not
bud E, at late flowering F2 and late pod G4 suitable for field-grown oilseed rape. The experi-
in field experiments. In these latter trials, seeds mental procedure was the same as previously
were harvested at maturity G5 for seed analysis described. For this experiment, the Tanto cultivar
and seed yield determination. In the pot experi- was chosen. From three-leaf stage to flowering, a
ments, plants were separated from the soil for treatment with a solution of micro-nutrients was
analysis. Roots were not recuperated at the first performed due to the visual symptoms of deficiency
sampling date due to the low biomass production observed on the leaves. All pot experiments were
at this stage. In field experiments, plants were cut conducted in a growth chamber. The growth condi-
at the soil surface in a square area of two rows tions were: 14 h day at 16°C and 10 h night at
and 1 m length 0.8 m 2. Roots were not sampled
12°C from sowing to flowering, 16 h day at 21°C in field experiments.
and 8 h night at 16°C from flowering to maturity Plants were then separated into roots pot
and 70 air humidity. The light intensities at the
trials, leaves, stems, pod walls and seeds, accord- plant
canopy height
varied from
250 to
ing to growth stages. Samples were dried at 80°C 350 mE m−2 s−1 at the rosette and full flowering
for 24 h and dry matter measured. The different plant parts of each replicate sample five and four
stage, respectively.
130 J. Fismes et al. European Journal of Agronomy 12 2000 127–141
Table 1 Details of the cultivation of oilseed rape Brassica napus L. in the two field and the two pot experiments
Field experiments Pot experiments
1995–96 1996–97
1995 1996
Previous cropping Winter wheat
Spring wheat Cultivar
Goeland Hybridol
Tanto Sowing date
240895 190896
150395 190296
Sowing rate 65 g m−2
1 seed pot−1 Fertilizer applications except NO and SO treatment
First N dressing 50 kg ha−1, in March
Equivalent of 200 kg ha−1, at sowing Second N dressing
150 kg ha−1, in April First S dressing
10 kg ha−1, in March Equivalent of 30 or 75 kg ha−1, at sowing
Second S dressing Remainder 20 or 65 kg ha−1, in April
Plant sampling dates and corresponding growth stages of oilseed rape First sampling
25496, E 16497, E
18495, B5 02496, B5
Second sampling 21596, F2
13597, F2 19695, F2
22496, F2 Third sampling
03696, G4 09797, G4
24795, G5 27596, G5
Harvest date 19796, G5
24797, G5 24795, G5
27596, G5
replicates per treatment for pot and field trials, In 1995’s pot experiment, it is important to note
respectively were ground and total N and S that the only-N application as UR and AN caused
contents were determined by the autoanalyzer NA total pod abortions, therefore the effect of S as
1500 Carlo Erba fitted for simultaneous analysis ATS cannot be determined. In contrast, slurry
of total N and S. The GLS contents were analyzed fertilized with ATS at 75 kg S ha−1 gave a signifi-
by HPLC equipped with a pump ThermoQest cant seed yield increase compared with slurry
8800, a sampler T.S.P. 8875, a Lichrospher treatment alone +20
. In 1996, with the cultivar chromatography
column 5 mm,
125×4 mm 2
Tanto, no pod abortions have been observed with Merck and a UV detector Knauer 87000 and
AN and UR application. But the lower dose of the oil content by NMR. Both compounds were
30 kg ha−1 as ATS did not increase significantly analyzed by the approved laboratory of CETIOM
seed yields even compared with the control, except using a pooled sample representative of the repli-
the treatment AN+ATS. cates. This laboratory specializes in the GLS and
In total, the seed yields from the growing season oil content analyses according to the norm NF
1995–96 field
experiment averaged
about EN ISO 916 7-1.
3.26 t ha−1 versus 4.16 t ha−1 from 1996–97. The In consequence, except the data of oil and GLS
results showed that the fertilization either with N contents which indicated only the trends, the
alone or with N plus S increased significantly seed remaining data were subject to variance analysis
productions, but the complementary addition of S and statistically compared according to Tukey’s
had no significant influence Table 3. The yields test at the 0.05 probability level.
from the second year were higher but, in terms of responses to fertilization, slightly lower +71
than the former +82 as compared with the
3. Results
