American Journal of Plant Sciences, 2011, 2, 334-344
doi:10.4236/ajps.2011.23038 Published Online September 2011 (http://www.SciRP.org/journal/ajps)
Growth and Development Responses of Tobacco
(Nicotiana tabacum L.) to Changes in Physical
and Hydrological Soil Properties Due to
Minimum Tillage
Francesca Orlando1, Marco Napoli1, Anna Dalla Marta1, Francesca Natali1, Marco Mancin i 2,
Camillo Zanchi1, Simone Orlandini2
1Department of Plant Soil and Environmental Science (DIPSA), University of Florence, Florence, Italy; 2Interdepartmental Centre of
Bioclimatology (CIBIC), University of Florence, Florence, Italy.
Received April 9th, 2011; revised May 24th, 2011; accepted June 7th, 2011.
ABSTRACT
Minimum tillage is a so il conservation pra ctice involving a red uction in soil distu rbance and topsoil compa ction, wh ic h
could minimize environmen ta l impact of th e toba cco cu ltivatio n system . The objectives o f this study were to evalua te the
development and growth responses of Nicotiana tabacum and the changes in the physical and hydrological soil proper-
ties after the application of two different treatments: minimum tillage (MT) and conventional tillage (CT). MT did not
cause any pronounced differences in the crop yield compared to CT, instead it positively affected the physical and hy-
drological soil properties and the plants’ vegetative growth. Under MT, the soil showed a higher structural stability
than CT with significantly lower compaction values. With MT the soil showed a higher capacity to main tain and store
water during the drought periods, evidenced by soil moisture values significantly higher than CT. Tobacco on MT
showed a good response, significantly prolonging the vegetative growth stage which at harvest determined a higher
stem heig h t, greater num ber of leaves an d l o nger internodes .
Keywords: Minimum Tillage, Phenology, Yield, Soil Moisture, Soil Compaction
1. Introduction
Soil management is a decisive factor for crop develop-
ment and growth, affecting the physical, biological and
chemical properties of the root environment. Compared
to conventional tillage (CT), minimum tillage (MT) is a
soil conservation practice capable of reducing soil dis-
turbance, wheel traffic compaction and soil erosion [1-3];
moreover conservative tillage can reduce the environ-
mental and economic costs of the cultivation systems
[4-6]. Studies on MT highlighted, since its first year of
application, changes in soil physical and hydraulic prop-
erties with an increase in soil moisture [7-14] and water
content at saturation [15], as well as an improvement in
water use efficiency for many crops [7,13].
Studies of MT on many seed crops showed good
yields that do not differ significantly from those obtained
with CT [8,11-13,16-23]. Moreover, authors reported
that already during the first year with MT it is possible to
reach the same yields as CT [7,12,20,23]. Some of them
explained these results as a consequence of the higher
available water, and consequently greater nitrogen avail-
ability, induced by MT especially during the driest sea-
sons [7] or in semi-arid condition [12].
Tobacco (Nicotiana tabacum L.) is particularly sus-
ceptible to water stress, a condition that severely affects
the yield with reductions in plant height, total dry matter,
number of leaves, leaf initiation rate and leaf area devel-
opment [24-26].
Previous research on tobacco showed that MT, com-
pared to CT, significantly reduces the erosion and total
run-off with less loss of suspended solids and nutrients
(i.e. nitrogen and phosphate compounds), and less pol-
lutant dispersion (pesticides, etc.) in water run-off [27-
30], playing a role in the development of a sustainable
agricultural system for this intensive crop cultivation.
However, there are few scientific works advocating

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and 335
Hydrological Soil Properties Due to Minimum Tillage
the use of MT on tobacco, and the primary factors limit-
ing the diffusion of this conservation tillage practice in-
clude the mistrust of the growers, who traditionally use
an intensive tillage system for this cash crop, and the
uncertainty surrounding crop growth and yield responses
[31].
The aim of this study was to analyze the effects of MT,
compared to CT, on physical and hydrological soil prop-
erties, with particular attention to soil surface compaction
and soil water availability, with an analysis of the re-
sponses of tobacco in terms of phenological development,
biomass growth and yield.
2. Materials and Methods
2.1. Experimental Design and Tillage Treatments
The experimental design was set up in four randomized
blocks, with a total of eight replications for treatment (Fig-
ure 1), in a level and pedologically homogeneous land. The
plots, measuring 140 m2 (20 m × 7 m) each, were treated
with two different soil tillage methods: MT and CT.
Thanks to the uniformity of the chemical, physical and
morphological properties of the soil in the experimental
land, the extensive survey design, including large plots
and many replications for treatment, and the meteoro-
logical analysis of the growing season, it was possible to
monitor the consequences on the soil and their effect on
the plants due to the tillage treatments, minimizing the
influence of the spatial and temporal variability and
evaluating the interaction between environmental vari-
ables and crop growth and development.
The MT plots were left until transplanting with stand-
ing stubble from the previous wheat crop (Triticum aes-
tivum L.). They were tilled on the same day as the trans-
plant with a rotating harrow (0.10 m deep) used to create
the transplanting bed. The CT plots were tilled according
to the traditional tillage management adopted by the farm:
with deep ploughing (0.40 m) in the winter of 2007-2008,
followed by a surface-disking tillage (0.10 m deep) in
March and a rotating harrow (0.10 m deep) on the same
day as the transplant. After the transplant the conven-
tional operation of hoeing (0.05 m deep) and propping up
were carried out for both treatments.
2.2. Experimental Site and General Conditions
The study was conducted on a farm near Montepulciano
Abbadia (Tuscany, Italy) (43˚08'37"N, 11˚49'58"E). The
area is predominantly characterized by alluvial and col-
luvial soils with a mild Mediterranean climate.
Meteorological data concerning precipitation (P), mean
(Tm) maximum (Tmax) and minimum (Tmin) air tem-
peratures, maximum (U%max) and mean (U%m) relative
Figure 1. Soil retention curve.
air humidity, were monitored at standard weather stations
situated near the experimental fields and acquired daily
from the “A.R.S.I.A. Agrometeorological Information
System” database.
The monthly averages of each meteorological variable,
potential evapotraspiration (ETp) and crop evapotra-
spiration (ETc), were calculated from May to August
2008 and for a climatological base period of 12 years
(from 1996 to 2007). The 2008 monthly averages were
compared with the 12 years monthly averages to verify
the climatic trend of the growth season and highlight any
anomalies with respect to the climatological base period.
ETp and ETc were calculated with the Priestley-Taylor
method [32] and taking into account the FAO recom-
mendations [33] for tobacco that consider a crop cycle
length of 110 days and the following crop coefficients
(Kc): during the initial stage 0.3 - 0.4 (20 days), 0.7 - 0.8
during the development stage (30 days), 1 - 1.2 during
the mid-season stage (30 days), 0.8 during the late season
stage (30 days). The ETc values were used to define the
irrigation scheduling.
Before the tillage, the soil of the experimental field
was characterized via physical and chemical analyses
according to the official methods [34,35].
Soil samples were collected using an auger: according
to an X-shaped pattern, five soil sub-samples were col-
lected in each plot at 0 - 0.10 m, 0.10 - 0.20 m and 0.20 -
0.30 m for physical characterization, and at 0 - 0.10 m,
0.20 - 0.30 m for chemical characterization.
Soil pH was measured potentiometrically using an
electronic pH meter (Intelligent pH Meter YK-2001PH,
Lutron Electronic Enterprise Co., Taiwan) with a glass
electrode in a 1:2.5 (mass fraction) suspension of air-dry
soil (10 g, <2 mm) in deionised water (pH in H2O). Elec-
trical conductivity (EC) was measured in a 1:5 air-dry
soil in deionised water extracted with a conductivity
probe (YK-200PCT, Lutron Electronic Enterprise Co.,
Taiwan). The calcium carbonate content (CaCO3) was

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and
336
Hydrological Soil Properties Due to Minimum Tillage
determined using a Bernard calcimeter, quantifying the
CO2 released when the sample was treated with hydro
chloric acid under a constant pressure and temperature
[36,37]. Total carbon and total nitrogen content was de-
termined by dry combustion at 1000˚C and gas-chroma-
tographic determination in an elementary Thermo Finni-
gan Flash EA 1112 CHNS analyzer, from 5.0 ± 0.1 mg
soil samples. The available phosphorus (P2O5) was ex-
tracted using the NaHCO3 method [38], after which the
P2O5 concentration in the extracts was determined col-
orimetrically by the phospho-molybdate [39]. The ex-
changeable potassium (K2O) was extracted using the
NH4Ac method, and the K2O concentration was deter-
mined by spectrophotometric analysis. The cation ex-
change capacity (CEC) was determined using the trie-
thanolamine-buffered BaC12 solution (c = 0.1 M) fol-
lowed by a re-exchange with aqueous MgC12 solution (c
= 0.1 M) [40,41].
The bulk density was determined by pouring the oven-
dried soil (105˚C) into a 250 ml cylinder containing 100 ml
of deionised water, and the texture was determined using the
pipette method [42]. The soil water retention curve was
derived with the Richard pressure plate extractor [43] meas-
uring the gravimetric water contents (w in kg·ha–1) at –1,
–20, –33, –100, –500, –1000 and –1500 kPa water potential
values. The soil mass was measured after oven drying the
samples (105˚C; 24 h) at all water potential values. The field
capacity (FC), the wilting point (WP) and the Available
Water Capacity (AWC) were determined with the Richard
plate. FC is the drained upper limit and WP is the lower
limit, both are equivalent to the amount of water retained by
the soil respectively at a suction pressure of –33 kPa and
–1500 kPa. The AWC is the difference between the water
contents at WP and at FC.
2.3. Agricultural Practices
The Virginia Bright tobacco was transplanted on 14 May
2008. The harvest was carried out at two different times
according to maturation grade, evidenced by a yellow co-
louring and curved bearing of the leaves, on the 85th and
106th days after transplant (DAT) for the basal leaves and
median-apical leaves respectively.
During the crop cycle, fertilization, weed control, irriga-
tion and topping (removal of flower buds) were performed
according to the traditional management adopted by the
local farmers. Two topping operations were carried out on
the 65th and 92nd DAT. The following fertilizers were dis-
tributed: 200 kg·ha–1 of K2SO4 and 200 kg·ha–1 of
Ca(H2PO4)2 in February, and 500 kg·ha–1 of a starter fertil-
izer (5:10:15) in May. The weed control was carried out
distributing 4 l ha–1 of a herbicide (a.p. glyphosate acid
36%) on 1 May and on 13 June.
The plots were irrigated using a rain sprinkler irrigation
system according to crop growth requirements. Irrigation
was implemented when water depletion in the soil profile,
owing to ETc, exceeded 40% of the AWC. This was calcu-
lated for the transplanting and initial plant development at a
depth of 0 - 0.15 m, and for the following plant develop-
ment at a depth of 0 - 0.40 m, obtaining an irrigation water
amount of 8 mm and 20 mm respectively. There were no
irrigations in May and June, because the rainfall was suffi-
cient for satisfying crop water requirements. During July
and August five irrigations were necessary on the 58th, 66th,
75th, 85th, and 99th DAT.
2.4. Measurements of Soil Proprieties
The relationships between the tillage treatments and the
changes in physical and hydrological soil proprieties were
monitored by measuring soil compaction and soil moisture
levels. The samplings for moisture determination were carried
out at a distance from rainy events or irrigations on three
points per plot at three depths (0 - 0.10 m, 0.10 - 0.20 m, 0.20
- 0.30 m) using a Soil Core Sampler (cylinders with a diame-
ter of 57 mm and length of 60 mm). Each sample was imme-
diately sealed in hermetic plastic bags and then weighed to
obtain the net fresh weight. The dry weights were taken after
drying in the oven at 105˚C and the soil moisture was calcu-
lated as percentage of dry weight. The soil compaction was
detected using a penetrometer (range 0 - 59 N·cm–2) on two
points per plot at three depths (0.10 m, 0.20 m, 0.30 m), and
three measurements repetitions were performed for each one.
The sampling times to detect the soil compaction and mois-
ture are described in Table 1.
Table 1. Timing of crop and soil surveys.
Survey timeCrop surveys:
plants per plot
Soil surveys:
points per plot
(DAT) NDDP H M C
13 10 10 9
28 122 12 9
44 10 10 9
57 2 40 9 6
71 10 25
77 9 6
85 122 12 20
98 10 10 9 6
106 122 12 20
Timing of crop and soil surveys with indications respectively of sampled
plants per plot and sampled points per plot. Legend: DAT = days after
transplant, ND = non-destructive measurements, D = destructive measure-
ments, P = phenological observations, H = measurements at harvest time, M
= moisture measurements, C = compaction measurements.

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and
Hydrological Soil Properties Due to Minimum Tillage
337
2.5. Measurements of Crop Growth and
Development
The crop growth and development were monitored on
plants selected randomly from the central area of each
plot. Meanwhile, the weeds, aphids or virus diffusion
were monitored observing the possible differences be-
tween the tillage treatments.
During the crop cycle the following were carried out:
non-destructive measurements for detecting stem height,
leaf number and mean internode length (height/leaf nu-
mber); destructive measurements for detecting area and
dry weight of the leaves; phenological observations for
monitoring the plants development stage. In addition,
during the two harvest times, surveys were carried out to
measure the number and dry weight of the mature leaves
per plant. The leaf area was measured with an electronic
planimeter (Delta-T, Dias II image analysis system, UK).
The dry leaf weight was determined after drying in a
ventilated oven at 50˚C. With the approaching flowering
stage, a growing lack of phenological homogeneity was
observed in the population: therefore, during the shift
period from the vegetative to the reproductive stage, the
phenological observations were extended to a larger
number of individuals per plot. The times of all crop
surveys and measurements are illustrated in Table 1.
The growth stages suggested for tobacco by the
CORESTA Guide (2009) [44] according to the BBCH
scale [45] were grouped in several main development
stages depending on the main tobacco growing periods
reported by the FAO [33]. The CORESTA classification
is founded on a universally-adopted extended BBCH
scale for uniformly coding phenologically-similar growth
stages of plants. The description of the phenological
classification adopted in our research and its corre-
sponding BBCH codes and FAO stages are illustrated in
Table 2.
Table 2. Description and coding of the phenologic al stages for tobacco.
Adopted Classification FAO Classification BBCH Scale
Code Stage Description Stage Length
(days) Stage Value
LD 1100 - 1105
E Initial
I
Early post-transplant stage. Less than 5 unfolded leaves, stem
reaches less than 0.15 m. SE 3100 - 3101
LD 1106 - 1110
L Initial
II
Late post-transplant stage. 6 - 10 unfolded leaves, stem reaches
less than 0.30 - 0.35 m.
Initial 20
SE 3102 - 3103
LD 1111 - 1120
K
Crop
Development
I
First growth stage (“Knee high”). 11 - 20 unfolded leaves, steam
reaches less than 0.55 - 0.6 m. SE 3104 - 3105
LD >1121
G
Crop
Development
II
Elongation and rapid growth stage. More than 21 unfolded
leaves, steam reaches 1 m but there is no hint of reproductive
organ formation.
Development30
SE 3106 - 3109
BF Pre-flowering
I
Bud Formation. Apical bud swelling but with inflorescence not
yet visible or only visible between the apical leaves. IE 50 - 51
BE Pre-flowering
II
Bud Emerging. Inflorescence emergence continuous till 1st co-
rolla visible but still closed. IE 52 - 55
CF Pre-flowering
III Close Flower. First petals visible but not yet open.
Med-season30
IE 56 - 59
OF Flowering
I
Open Flower. From beginning of flowering, first petals open, to
50% of flowers open. FW 60 - 65
AF Flowering
II
Advanced Flowering. Continuous stage until more than 90% of
flowers open
Late season30
FW 66 - 69
Description and coding of the phenological stages observed for tobacco in the present study and compliance with the main growth stages suggested by the FAO
and by BBCH classification of CORESTA. Legend: unfolded = leaves > 4 cm length, LD = leaf development, SE = stem elongation, IE = inflorescence emer-
gence, FW = flowering.

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and
338
Hydrological Soil Properties Due to Minimum Tillage
2.6. Statistical Data Analysis
The statistical elaborations and the descriptive statistical
analysis were carried out with the SPSS 15.0 software for
windows. Three levels of significance were considered:
at P ≤ 0.05, P ≤ 0.01, and P ≤ 0.001. One-way analyses
of variance were carried out with the general univariate
linear model (ANOVA) on plant growth data and soil
moisture and compaction data. The data were analyzed
for each measurement date and concerning the soil, for
each depth level, considering blocks and tillage treat-
ments as the fixed factor. Bonferroni’s post-hoc test was
performed for the multiple comparisons. The phenologi-
cal data were analyzed using the Chi-square non-para-
metric test considering the frequencies of individuals at
each phenological stage.
3. Results and Discussion
3.1. Environmental Conditions
Compared to 12-year means, May 2008 (from 0 to 17
DAT) was characterized by lower air temperature and
ETP values and higher air humidity, while June (from 18
to 47 DAT) was a rainy month with a higher rainfall and
air humidity. July and August (from 57 to 106 DAT) were
particularly dry with rainfall and air humidity lower than
the mean.
According to the USDA classification, the soil texture
class was “clay-loam”. The experimental field showed
homogeneous soil conditions with uniform chemical,
physical and hydrological properties among the plots
(Table 3, Figure 1).
3.2. Response of Soil Physical and Hydrological
Properties to Tillage Treatments
The soil compaction level was influenced by the treat-
ment (Table 4). The measurements on three soil depths
showed a significantly lower soil compaction in MT than
in CT.
The soil moisture was influenced by the treatments
during the drought periods from 57 to 98 DAT and
higher values were observed in MT (Table 5 ). Compared
to CT, the MT soil showed a significantly higher capac-
ity to maintain and store the water at the three soil depths
when the mean moisture content decreased, coming near
or dropping below the permanent wilting point of 15%.
Table 3. Soil characterization.
Soil parameters
Chemical Physical Hydrological
GWC (%)
OC (%) 1 ± 0.18 BD (t·m–3) 1.45 ± 0.11 Saturation 32.5
Total N (%) 0.07 ± 0.01 Sand (%) 36.9 FC 24.1
P2O5 (mg·kg–1) 14.9 ± 2.1 Silt (%) 28 WP 15.1
K2O (cmol + kg–1) 0.26 ± 0.05 Clay (%) 35.1 AWC 9
CaCO3 (%) 7.45 ± 0.7
EC (dS m–1) 0.06 ± 0.01
CEC (cmol + kg–1) 20.7 ± 0.5
pH 8.2 ± 0.1
Soil characterization: chemical, physical and hydrological parameters measured in January 2008. Legend: OC = organic carbon, EC = electrical conductivity, CEC =
cation exchange capacity, BD = bulk density, GWC = gravimetric water content, FC = field capacity, WP = wilting point, AWC = available water capacity.
Table 4. Values of soil compaction.
Compaction level (N cm–2)
Time (DAT) Depth (m) CT MT Statistical significance
0.10 38.85 21.48 ***
0.20 38.06 30.51 n.s.
57
0.30 38.95 24.82 ***
0.10 17.27 6.18 ***
0.20 58.08 15.21 *** 77
0.30 57.39 16.09 ***
0.10 55.62 41.10 ***
0.20 64.65 46.60 * 97
0.30 66.02 45.62 **
Mean values of soil compaction detected at three soil depths with the significant difference levels between tillage treatments. Legend: DAT = days after trans-
plant, CT = conventional tillage, MT = minimum tillage, n.s. = not significant, * significant at P ≤ 0.05, ** significant at P ≤ 0.01, *** significant at P ≤ 0.001.

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and 339
Hydrological Soil Properties Due to Minimum Tillage
Table 5. Values of soil moisture.
Soil moisture (%)
Time (DAT) Depth (m) CT MT Statistical significance
0.10 15.85 15.76 n.s.
0.20 15.79 15.69 n.s. 13
0.30 15.61 16.13 n.s.
0.10 18.89 19.21 n.s.
0.20 18.89 20.02 n.s. 28
0.30 20.06 20.46 n.s.
0.10 17.33 18.57 n.s.
0.20 18.26 19.57 n.s. 44
0.30 18.92 19.37 n.s.
0.10 8.54 9.57 n.s.
0.20 10.48 11.73 *** 57
0.30 12.50 15.12 ***
0.10 9.38 13.71 ***
0.20 10.48 13.20 *** 77
0.30 10.54 13.28 ***
0.10 7.54 7.98 n.s.
0.20 8.29 9.22 n.s. 98
0.30 7.68 9.0 *
Values of soil moisture detected at three soil depths with the significant difference levels between tillage treatments. Legend: DAT = days after transplant, CT =
conventional tillage, MT = minimum tillage, n.s. = not significant, * significant at P ≤ 0.01, *** significant at P ≤ 0.001.
The soil compaction results suggest that the CT was
not able to create a stable structure and that its positive
effects on the physical soil properties was annulled by
the compression action due to wheel transit of the agri-
cultural machines used to carry out the hoeing, propping
up and topping during the crop growing season. Con-
versely, the lower soil compaction values recorded with
MT show that via the reduction of the soil disturbance
level, this tillage practice could be able to improve the
physical soil properties and structure stability, minimize-
ing the negative consequences of the wheel transiting action.
Moreover, the results pointed out that MT was able to
improve the hydrological soil properties, furthering the
moisture retention during the drought period. This may
be due to the increased capacity to capture and store
moisture compared to CT, depending on the changes in
soil porosity during the second half of the crop cycle
caused by agricultural traffic.
3.3. Crop Phenology
During the vegetative phase, the crop showed homoge-
neous phenological development and there were no sig-
nificant differences between treatments. At 13 and 28
DAT all the plants were respectively in the early (E) and
late (L) establishment stage. Similarly, at 44 DAT all the
plants were in the first vegetative growth stage (K). In-
stead, from the beginning of the reproductive phase the
plantation showed a non-homogeneous phenological de-
velopment with the simultaneous presence of plants at
the vegetative growth, pre-flowering and flowering stages.
At 57 and 71 DAT, significant differences were ob-
served between the treatments (Table 6). Compared to
CT, the plants in MT showed the tendency to delay the
reproductive stage and prolong the vegetative growth
stage with a lower frequency in the flowering stages (FC,
FO) at 57 DAT, and a lower frequency in advanced
flowering stage (FF) at 71 DAT. Conversely, after 99
DAT, there were no differences between the treatments
and all the plants reached the reproductive phase, which
led to the advanced flowering stage (FF).
The shift period from vegetative to reproductive stage,
between 57 and 77 DAT, coincided with the drought
months characterized by a soil moisture content below or
close to the permanent wilting point (Tables 3 and 5), so
the flowering onset time and the duration of vegetative
growth stage were probably influenced by the different
soil moisture status due to the tillage treatment.
In fact many studies showed how water deficit is able

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and
340
Hydrological Soil Properties Due to Minimum Tillage
to modify the phenology, enhancing flowering and caus-
ing an early switch of development from the vegetative
to the reproductive stages in many horticultural, forestry
and grain cultivations, including Rhododendron L. [46],
Litchi chinensis Sonn. [47], Picea engelmanni Parry. [48],
Pyrus communis L. [49], Citrus L. [50], Eriobotrya ja-
ponica Thunb. [51], Triticum aestivum L. [52,53], Hor-
deum vulgare L. [53], and Glycine max L. [54].
The results suggest that the higher soil moisture in MT,
involving less water stress, was able to affect the phe-
nological development of the crop, furthering vegetative
growth thanks to the delay of flowering onset. The en-
hancing of the vegetative growth during the drought pe-
riod is a very important aspect for tobacco, a crop for
which the leaves represent the main product.
3.4. Crop Growth and Production
During the field surveys, no weed incidence differences
were detected between the two tillage treatments. More-
over, no attacks by aphids or virus were observed during
the tobacco growing season. Therefore, from this point of
view the plants with MT were not disadvantaged and the
conventional treatments for the weed and pathogen con-
trol were sufficient in both the MT and CT plots.
During the non-destructive surveys, significant differ-
ences were observed between the two treatments with
regard to stem height, number of leaves and average in-
ternode lengths (Table 7). In the first three surveys the
plant growth appeared significantly improved by CT
treatment: however, after 45 DAT, this tendency changed
and the plant growth increased in MT.
Table 6. Phenological stages frequencies.
Frequency
Time (DAT) Phenological Stage CT MT Statistical Significance
G 88 146 ***
BF 36 46 n.s.
BE 135 121 n.s.
FC 51 7 ***
57
FO 10 1 **
G 17 27 n.s.
BF 4 12 *
BE 3 11 *
FC 16 11 n.s.
FO 5 26 ***
71
FF 155 113 **
Frequencies of plants in the different phenological stages at 57 and 71 DAT with the significant difference levels between tillage treatments. Legend: DAT =
days after transplant, CT = conventional tillage, MT = minimum tillage, G = II stage vegetative growth, BF = bud formation stage, BE = bud emerging stage,
FC = closed flower stage, FO = open flower stage, FF = advanced flowering stage, n.s. = not significant, * significant at P ≤ 0.05, ** significant at P ≤ 0.01, ***
significant at P ≤ 0.001.
Table 7. Non-destructive surveys: growth parameters.
Time (DAT) Stem height (cm) Statistical
significance
Leaves
number
Statistical
significance
Average internode
length (cm)
Statistical
significance
CT MT CT MT CT MT
13 8.60 7.9 ** 4.35 4.06 * 2.02 1.99 n.s.
28 23.35 20.56 *** 8.54 7.91 *** 2.76 2.62 **
44 55.33 52.82 *** 13.21 12.45 ** 4.18 4.09 n.s.
71 109.71 130.78 *** 18.10 21.50 *** 6.10 6.12 n.s.
85 146.59 152.68 n.s. 22.35 21.56 n.s. 6.64 7.16 ***
99 109.00 122.78 *** 17.39 18.43 * 6.38 6.75 **
106 112.23 126.69 *** 18.68 19.63 ** 6.05 6.49 ***
Growth parameters measured during the non-destructive surveys with the significant difference levels between tillage treatments. Legend: DAT = days after
transplant, CT = conventional tillage, MT = minimum tillage, n.s. = not significant, *, significant at P ≤ 0.05; **, significant at P ≤ 0.01; ***, significant at P ≤
0.001.

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and 341
Hydrological Soil Properties Due to Minimum Tillage
Table 8. Destructive surveys: growth parameters.
Time (DAT) Stem height (cm) Leaf number Average internode
length (cm) Leaf area (cm2) Dry leaf weight (g)
CT MT CT MT CT MT CT MT CT MT
28 22.44 21.50 7.81 7.81 2.89 2.78 837.53 732.54 3.92 3.50
57 99.94 93.37 16.56 16.87 5.95 5.52 6885.75 7384.42 55.96 56.78
85 166.37 188.00 24.87 26.12 6.74 7.24 13342.78 16071.0 88.91 101.66
106 112.50 116.00 18.87 17.87 6.06 6.51 12945.17 15149.0 107.83 115.08
Mean growth parameters measured during the destructive surveys. Legend: DAT = days after transplant, CT = conventional tillage, MT = minimum tillage.
Table 9. Yields.
Yield (g/plant) Yield (leaf number/plant)
Time (DAT) CT MT
Statistical
significance CT MT
Statistical
significance
83 19.06 20.92 * 3.85 4.26 **
106 64.04 65.60 n.s. 10.41 11.07 n.s.
Tobacco yields with the significant difference levels between tillage treatments. Legend: DAT = days after transplant; CT = conventional tillage; MT = mini-
mum tillage; n.s. = not significant; *, significant at P ≤ 0.05; **, significant at P ≤ 0.01.
During the destructive surveys, even though no sig-
nificant differences were observed between the tillage
treatments, the trend confirmed the results of the non-
destructive surveys (Table 8). In fact, at the beginning
(28 DAT), the CT plants showed higher values for all the
growth parameters, while at 57 DAT the values of leaf
area and dry weight were lower than those of MT, and
after 85 DAT they showed lower values than MT for all
the growth parameters.
The plant yield data confirmed that plants in MT pro-
duce a higher leaf number and dry weight than CT in
both harvests, but the differences were only significant
for the first one (Table 9).
The results suggest that the impact of MT on physical
and hydrological soil properties positively affected the
vegetative growth and productivity of tobacco. With MT,
the plants tended to have higher values for the measured
growth and harvest parameters than with CT. It is also
possible to suggest that by influencing the tobacco
phenology with the prolongation of the growth stage, the
MT improved the leaf production in the second half of
life cycle.
4. Conclusions
The adopting of MT on Nicotiana tobacco did not deter-
mine significant differences in the crop harvests com-
pared to CT, however it had a positive influence on the
physical and hydrological soil properties and the phe-
nological development of the plants, without any in-
crease in the incidence of weeds. In fact, the results
showed that MT is capable of improving the physical soil
stability and soil water content, while delaying the flow-
ering and prolonging the vegetative growth which bene-
fits the leaf yield of tobacco, a crop that is highly suscep-
tible to water stress.
The tobacco production can benefit from the MT sys-
tem firstly because, being a transplanted crop, it requires
less tilled seedbeds than seed crops, and secondly, due to
being an intensive cultivation system, conventional doses
of chemical herbicides could suffice for containing the
incidence of weeds without any changes to weed control
management.
MT may represent a valid means of reducing envi-
ronmental impact and obtaining economic savings for
tobacco cultivation.
5. Acknowledgements
We express our gratitude to the Vessichelli Cosimo farm
for its collaboration and ISMEA (Institute of Services for
the Agricultural and Food Market) for its support.
REFERENCES
[1] G. Chisci and C. Zanchi, “The Influence of Different
Tillage Systems and Different Crops on Soil Losses on
Hilly Silty-Clayey Soil,” In: R. P. C. Morgan, Ed., Soil
Conservation, Problems and Prospects, John Wiley &
Sons, Inc., Hoboken, 1980, pp. 211-217.
[2] W. Pansak, T. H. Hilger, G. Dercon, T. Kongkaew and G.
Cadisch, “Changes in the Relationship between Soil Ero-
sion and N Loss Pathways after Establishing Soil Con-
servation System in Uplands of Northeast Thailand,” Ag-

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and
342
Hydrological Soil Properties Due to Minimum Tillage
riculture, Ecosystems & Environment, Vol. 128, 2008, pp.
167-176.
[3] J. N. Tullberg, P. J. Ziebarth and Y. Li, “Tillage and Traf-
fic Effects on Runoff,” Australian Journal of Soil Re-
search, Vol. 39, No. 2, 2001, pp. 249-257.
doi:10.1071/SR00019
[4] N. Koga, H. Tsuruta, H. Tsuji and H. Nakano, “Fuel
Consumption-Derived CO2 Emissions under Conven-
tional and Reduced Tillage Cropping Systems in Northern
Japan,” Agriculture, Ecosystems & Environment, Vol. 99,
2003, pp. 213-219. doi:10.1016/S0167-8809(03)00132-4
[5] M. L. Sanchez, M. I. Ozores, R. Colle, M. J. Lopez, B.
De. Torre, M. A. Garcia and I. Perez, “Soil CO2 Fluxes in
Cereal Land Use of the Spanish Plateau: Influence of
Conventional and Reduced Tillage Practices,” Chemos-
phere, Vol. 47, 2002, pp. 837-844.
[6] C. H. Sijtsma, A. J. Campbell, N. B. McLaughlin and M.
R. Carter, “Comparative Tillage Costs for Crop Rotations
Utilizing Minimum Tillage on Farm Scale,” Soil and
Tillage Research, Vol. 49, No. 3, 1998, pp. 223-231.
doi:10.1016/S0167-1987(98)00175-5
[7] C. Cantero-Martinez, P. Angas and J. Lampurlanes, “Gr-
owth, Yield and Water Productivity of Barley (Hordeum
vulgare L.) Affected by Tillage and N Fertilization in
Mediterranean Semiarid, Rainfed Conditions of Spain,”
Field Crops Research, Vol. 84, No. 3, 2003, pp. 341-357.
doi:10.1016/S0378-4290(03)00101-1
[8] D. Chatskikh, J. E. Olesen, E. M. Hansen, L. Elsgaard
and B. M. Petersen, “Effects of Reduced Tillage on Net
Greenhouse Gas Fluxes from Loamy Sand Soil under
Winter Crops in Denmark,” Agriculture, Ecosystems &
Environment, Vol. 128, No. 1-2, 2008, pp. 117-126.
doi:10.1016/j.agee.2008.05.010
[9] S. De. Gryze, J. Six, H. Bossuyt, K. Van. Oost and R.
Merckx, “The Relationship between Landform and the
Distribution of Soil C, N, and P under Conventional and
Minimum Tillage,” Geoderm a, Vol. 144, 2008, pp. 180-188.
[10] K. P. Fabrizzi, F. O. Garcìa, J. L. Costa and L. I. Picone,
“Soil Water Dynamics, Physical Properties and Corn and
Wheat Responses to Minimum Tillage and No-Tillage
Systems in the Southern Pampas of Argentina,” Soil and
Tillage Research, Vol. 81, No. 1, 2005, pp. 57-69.
doi:10.1016/j.still.2004.05.001
[11] C. Giordani., P. Sani and C. Zanchi, “Traditional Tillage
versus Reduced Strip Tillage: Their Effects on Soil
Moisture, Crop Production, Soil Erosion, Weeds Diffu-
sion, and Economical Aspects,” Proceedings of the 3rd
International Conference on Land Degradation: New
Trends toward Global Sustainability, Rio De Janeiro, 17-
21 September 2001, p. 110.
[12] K. Habtegebrial, B. R. Singh and M. Haile, “Impact of
Tillage and Nitrogen Fertilization on Yield, Nitrogen Use
Efficiency of Tef (Eragrostis Tef (Zucc.) Trotter) and Soil
Properties,” Soil and Tillage Research, Vol. 94, No. 1,
2007, pp. 55-63. doi:10.1016/j.still.2006.07.002
[13] G. P. Lafond, W. E. May, F. C. Stevenson and D. A.
Derksen, “Effects of Tillage Systems and Rotations on
Crop Production for a Thin Black Chernozem in the Ca-
nadian Prairies,” Soil and Tillage Research, Vol. 89, No.
2, 2006, pp. 232-245. doi:10.1016/j.still.2005.07.014
[14] G. A. Peterson, A. D. Halvorson, J. L. Havlin, O. R.
Jones, D. J. Lyon and D. L. Tanaka, “Reduced Tillage
and Increasing Cropping Intensity in the Great Plains
Converses Soil C,” Soil and Tillage Research, Vol. 47,
No. 3-4, 1998, pp. 207-218.
doi:10.1016/S0167-1987(98)00107-X
[15] K. D’Haene, J. Vermang, W. M. Cornelis, B. L. M. Leory,
W. Schiettecatte, S. De. Neve, D. Gabriels and G. Hof-
man, “Reduced Tillage Effects on Physical Properties of
Silt Loam Soils Growing Root Crops,” Soil and Tillage
Research, Vol. 99, 2008, pp. 279-290.
[16] K. Areya, S. Sharma, R. M. Bajracharya and N. P.
Rajbhandari, “Applications of Reduced Tillage in Hills of
Central Nepal,” Soil and Tillage Research, Vol. 88, No.
1-2, 2006, pp. 16-29. doi:10.1016/j.still.2005.04.003
[17] K. Areya, S. Sharma, R. M. Bajracharya and N. P.
Rajbhandari, “Developing a Sustainable Agro-System for
Central Nepal Using Reduced Tillage and Straw Mulch-
ing,” Journal of Environmental Management, Vol. 88, No.
3, 2008, pp. 547-555. doi:10.1016/j.jenvman.2007.03.017
[18] A. Berner, I. Hildermann, A. Fliebach, L. Pfiffner, U.
Niggli and P. Mader, “Crop Yield and Soil Fertility Re-
sponse to Reduced Tillage under Organic Management,”
Soil and Tillage Research, Vol. 101, No. 1-2, 2008, pp.
89-96. doi:10.1016/j.still.2008.07.012
[19] X. Hao, C. Chang, R. L. Conner and P. Bergen, “Effect of
Minimum Tillage and Crop Sequence on Crop Yield and
Quality under Irrigation in Southern Alberta Clay Loam
Soil,” Soil and Tillage Research, Vol. 59, No. 1-2, 2001,
pp. 45-55. doi:10.1016/S0167-1987(00)00185-9
[20] J. L. Hernanz, V. S. Giron and C. Cerisola, “Long-Term
Energy Use and Economic Evaluation of Three Tillage
System for Cereal and Legume Production in Central
Spain,” Soil and Tillage Research, Vol. 35, No. 4, 1995,
pp. 183-198. doi:10.1016/0167-1987(95)00490-4
[21] D. B. Ishaya, P. Tunku and N. C. Kuchinda, “Evaluation
of Some Weed Control Treatments for Long Season
Weed Control in Maize (Zea Mays L.) under Zero and
Minimum Tillage at Samaru, in Nigeria,” Crop Protec-
tion, Vol. 27, 2008, pp. 1047-1051.
[22] S. K. Jalota, G. S. Buttar, A. Sood, G. B. S. Chahal, S. S.
Ray and S. Panigrahy, “Effects of Sowing Date, Tillage
and Residue Management on Productivity of Cotton
(Gossypium hirsutum L.) - Wheat (Triticum aestivum L.)
System in Northwest India,” Soil and Tillage Research,
Vol. 99, No. 1, 2008, pp. 76-83.
doi:10.1016/j.still.2008.01.005
[23] B. Tulema, J. B. Aune, F. H. Johnsen and B. Vanlauwe,
“The Prospects of Reduced Tillage in Tef (Eragrotis tef
Zucca) in Gare Arera, West Shawa Zone of Oromiya,
Ethiopia,” Soil and Tillage Research, Vol. 99, No. 1,
2008, pp. 58-65. doi:10.1016/j.still.2007.12.001

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and 343
Hydrological Soil Properties Due to Minimum Tillage
[24] R. çakir and U. çebi, “Growth and Dry Matter Accumula-
tion Dynamics off Flue-Cured Tobacco under Different
Soil Moisture Regimes,” Journal of Agronomy, Vol. 5,
2006, pp. 78-86.
[25] B. F. Clough and F. L. Milthorpe, “Effects of Water
Deficit on Leaf Development in Tobacco,” Australian
Journal of Plant Physiology, Vol. 2, No. 3, 1975, pp.
291-300. doi:10.1071/PP9750291
[26] J. M. Hopkinson, “Effects of Early Drought and Trans-
planting on the Subsequent Development of the Tobacco
Plant,” Australian Journal of Agricultural Research, Vol.
19, No. 1, 1968, pp. 47-57. doi:10.1071/AR9680047
[27] B. L. Benham, D. H. Vaughan, M. K. Laird, B. B. Ross
and D. R. Peek, “Surface Water Quality Impacts of Con-
servation Tillage Practices on Burley Tobacco Production
Systems in Southwest Virginia,” Water, Air & Soil Pollu-
tion, Vol. 179, No. 1-4, 2007, pp. 159-166.
doi:10.1007/s11270-006-9221-z
[28] L. Fisher, “Potential for Reduced Tillage Tobacco Pro-
duction in North Carolina,” Proceedings of the 26th
Southern Conservation Tillage Conference for Sustain-
able Agriculture, North Carolina, 8-9 June 2004, Technical
Bulletin (TB), No. 321, pp. 161-162.
[29] D. G. Shilling, A. D. Worsham and D. A. Danehower,
“Influence of Mulch, Tillage and Diphenamid on Weed
Control, Yield and Quality in No-Till Flue-Cured To-
bacco (Nicotiana tabcum),” Weed Science, Vol. 34, 1986,
pp. 738-744.
[30] D. C. Yoder, T. L. Cope, J. B. Wills and H. P. Denton,
“No-Till Transplanting of Vegetables and Tobacco to
Reduce Erosion and Nutrient Surface Runoff,” Journal of
Soil and Water Conservation, Vol. 60, No. 2, 2005, pp.
68-72.
[31] B. Pearce and G. Schwab, “Field Selection, Tillage and
Fertilization,” In: K. Seebold and B. Pearce, Eds., Ken-
tucky Tobacco Production Guide, Publishers of Univer-
sity of Kentucky, Lexington, 2008, pp. 23-25.
[32] C. H. B. Priestley and R. J. Taylor, “On the Assessment
of Surface Heat Flux and Evaporation Using Large-Scale
Parameters,” Monthly Weather Review, Vol. 100, 1972,
pp. 81-92.
doi:10.1175/1520-0493(1972)100<0081:OTAOSH>2.3.C
O;2
[33] J. Doorenbos and A. H. Kassam, “Yield Response to
Water,” FAO Irrigation and Drainage Paper 33, Food
and Agriculture Organization of the United Nations, Rome,
1986.
[34] Italian Ministry of Agricultural, Food and Forestry-
Policies (MIPAAF), “Metodi Ufficiali Di Analisi Fisica
Del Suolo, Ministerial Decree of 01/08/97,” Official Ga-
zette―Ordinary Supplement, No. 204, 2 September 1997.
[35] Italian Ministry of Agricultural, Food and Forestry Poli-
cies (MIPAAF), “MetodiUfficiali Di AnalisiChimica Del
Suolo, Ministerial Decree of 13/09/99,” Official Ga-
zette―Ordinary Supplement, No. 248, 21 October 1999.
[36] J. D. Milliman, “Marine Carbonates. Recent Sedimentary
Carbonates Part 1,” 14th Edition, Springer-Verlag, New
York, 1974.
[37] G. Muller and M. Gatsner, “Chemical Analysis,” Neues
Jahrbuch fur Mineralogie-Monatshefte, Vol. 10, 1971, pp.
466-469.
[38] S. R. Olsen, C. V. Cole, F. S. Watanabe and L. A. Dean,
“Methods of Soil Analysis: Physical Properties, Part 1,”
In: A. Klute, Ed., Agronomy Monograph No. 9, ASA and
SSSA, Madison, 1954, pp. 403-430.
[39] J. Murphy and J. P. Riley, “A Modified Single Solution
Method for the Determination of Phosphate in Natural
Waters,” Analytica Chimica Acta, Vol. 27, 1962, pp.
31-36. doi:10.1016/S0003-2670(00)88444-5
[40] C. L. Bascomb, “Rapid Method for the Determination of
the Cation Exchange Capacity of Calcareous and
Non-Calcareous Soils,” Journal of the Science of Food
and Agriculture, Vol. 15, No. 12, 1964, pp. 821-823.
doi:10.1002/jsfa.2740151201
[41] A. Mehlich, “Determination of Cation and Anion Exchange
Properties of Soils,” Soil Science, Vol. 66, No. 6, 1948,
pp. 429-445. doi:10.1097/00010694-194812000-00004
[42] G. W. Gee and J. W. Bauder, “Particle-Size Analysis,” In:
A. Klute, Ed., Methods of Soil Analysis: Part 1. Agron-
omy Monograph No. 9, ASA, Madison, 1986.
[43] L. A. Richards and M. Fireman, “Pressure-Plate Apparatus
for Measuring Moisture Sorption and Transmission by
Soils,” Soil Science, Vol. 56, No. 6, 1943, pp. 395-404.
doi:10.1097/00010694-194312000-00001
[44] Cooperation Centre for Scientific Research Relative to
Tobacco (CORESTA), “A Scale for Coding Growth
Stages in Tobacco Crops,” CORESTA Guide N˚7, Feb-
ruary 2009.
[45] U. Meier, “Growth Stage of Mono- and Dicotyledonous
plants,” 2nd Edition, Federal Biological Research Centre
for Agriculture and Forestry, Braunschweig, 2001.
[46] R. G. Sharp, M. A. Else, R. W. Cameron and W. J. Da-
vies, “Water Deficits Promote Flowering in Rhododen-
dron via Regulation of Pre and Post Initiation Develop-
ment,” Scientia Horticulturae, Vol. 120, No. 4, 2009, pp.
511-517. doi:10.1016/j.scienta.2008.12.008
[47] R. A. Stern, I. Adato, M. Goren, D. Eisenstein and S.
Gazit, “Effects of Autumnal Water Stress on Litchi
Flowering and Yield in Israel,” Scientia Horticulturae,
Vol. 54, No. 4, 1993, pp. 295-302.
doi:10.1016/0304-4238(93)90108-3
[48] S. D. Ross, “Promotion of Flowering in Potted Picea
Engelmanni Grafts Effects of Heat Drought Gibberellin A
4-7 and Their Timing,” Canadian Journal of Forest Re-
search, Vol. 15, No. 4, 1986, pp. 618-624.
doi:10.1139/x85-101
[49] P. D. Mitchell, D. J. Chalmers, P. H. Jerie and G. Burge,
“The Use of Initial Withholding of Irrigation and Tree
Spacing to Enhance the Effect of Regulated Deficit Irri-
gation on Pear Trees,” Journal of the American Society
for Horticultural Science, Vol. 111, 1986, pp. 858-861.

Growth and Development Responses of Tobacco (Nicotiana tabacum L.) to Changes in Physical and
Hydrological Soil Properties Due to Minimum Tillage
344
[50] A. J. Krajewski and E. Rabe, “Citrus Flowering: A Criti-
cal Evaluation,” Journal of Horticultural Science, Vol. 70,
1995, pp. 357-374.
[51] J. Cuevas, V. Pinillos, M. L. Caete, M. Gonzlez, F.
Alonso, M. D. Fernandez and J. J. Hueso, “Optimal Lev-
els of Postharvest Deficit Irrigation for Promoting Early
Flowering and Harvest Dates in Loquat (Eriobotrya Ja-
ponica Lindl.),” Agricultural Water Management, Vol. 96,
No. 5, 2009, pp. 831-838.
doi:10.1016/j.agwat.2008.11.002
[52] F. Ewert, D. Rodriguez, P. Jamieson, M. A. Semenov, R.
A. C. Mitchell, J. Goudriaan, J. R. Porter, B. A. Kimball,
P. J. Pinter Jr., R. Manderscheid, H. J. Weigel, A. Fang-
meier, E. Fereres and F. Villalobos, “Effects of Elevated
CO2 and Drought on Wheat: Testing Crop Simulation
Models for Different Experimental and Climatic Condi-
tions,” Agriculture, Ecosystems & Environment, Vol. 93,
No. 1-3, 2002, pp. 249-266.
doi:10.1016/S0167-8809(01)00352-8
[53] G. S. Mc Master and W. W. Wilhem, “Phenological Re-
sponses of Wheat and Barley to Water and Temperature:
Improving Simulation Models,” The Journal of Agricul-
tural Science, Vol. 141, No. 2, 2003, pp.129-147.
doi:10.1017/S0021859603003460
[54] D. Desclaux and P. Roumet, “Impact of Drought Stress
on the Phenology of Two Soybean (Glycine Max L. Merr)
Cultivars,” Field Crops Research, Vol. 46, No. 1-3, 1996,
pp. 61-70. doi:10.1016/0378-4290(95)00086-0