Field Crops Research 99 (2006) 35–47
www.elsevier.com/locate/fcr
Integrated assessment of cropping systems
in the Eastern Indo-Gangetic plain
B. Biswas a,1, D.C. Ghosh b, M.K. Dasgupta b, N. Trivedi a,1,
J. Timsina c, A. Dobermann d,*
a
Directorate of Agriculture, Government of West Bengal, Kolkata 700 001, India
Institute of Agriculture (Palli-Siksha Bhavana), Visva-Bharati, Sriniketan 731 236, West Bengal, India
c
CSIRO Land and Water, Griffith, NSW 2680, Australia
d
Department of Agronomy & Horticulture, University of Nebraska, Lincoln, P.O. Box 830915, Lincoln, NE 68583-0915, USA
b
Received 22 August 2005; received in revised form 28 February 2006; accepted 5 March 2006
Abstract
Both intensification and diversification of cropping systems may allow improving the productivity and sustainability of agricultural
production in the Indo-Gangetic Plain (IGP), but the choices to be made require integrated assessment of various cropping systems. A field
experiment was conducted from 1999 to 2002 on a sandy clay loam (Inceptisol) to evaluate nine predominant cropping systems in West
Bengal, India. Productivity, energy use efficiency, and nutrient uptake generally increased with increasing cropping intensity. Positive residual
effects of potato and jute on yield and energy output of subsequently grown crops were observed as well as maintenance or improvement of
soil properties such as soil organic matter, available P, and available K. The P balance was positive for most systems, except for jute-containing
systems. However, negative K balances occurred due to almost complete removal of crop biomass in all systems, suggesting that
recommended rates of applied K fertilizer were to low for sustaining soil K supply over the longer term. Cropping systems containing
potato had the highest levels of yield, net return, benefit to cost ratio and energy productivity, but energy use efficiency was reduced due to
higher energy consumption in these systems. Jute–wheat and jute–rapeseed–rice systems showed high energy use efficiency along with
moderate cost and return. Based on economic considerations alone, jute–potato–rice, rice–potato–rice and rice–potato–sesame can be
recommended as cropping systems for resource-rich growers in the eastern part of the IGP. Systems such as jute–wheat, rice–wheat and jute–
rapeseed–rice appear to be most suitable for small and marginal farmers that cannot afford the large production costs associated with crops
such as potato.
# 2006 Elsevier B.V. All rights reserved.
Keywords: Cropping systems; Productivity; Economics; Energy use efficiency; Soil fertility; Nutrient budget; Rice–wheat system; India
1. Introduction
The Lower Gangetic Plain forms the eastern part of the
Indo-Gangetic Plain (IGP), one of the world’s most important
agricultural eco-regions (Timsina and Connor, 2001). Most of
the Lower Gangetic Plain is located in the state of West
* Corresponding author. Tel.: +1 402 472 1501.
E-mail addresses: [email protected] (B. Biswas),
[email protected] (A. Dobermann).
1
Present address: Zonal Adaptive Research Station, Government of West
Bengal, Mohitnagar, Jalpaiguri 735 101, India.
0378-4290/$ – see front matter # 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.fcr.2006.03.002
Bengal, India, which is further divided into six agro-climatic
sub regions: (i) the northern hilly zone, (ii) the Tarai-Teesta
flood plain, (iii) the Gangetic flood plain, (iv) the coastal flood
plain, (v) the Vindhya old flood plain and (vi) the undulating
lateritic sub-region of the Eastern Plateau Region (SenGupta,
2001). Of those, the Gangetic flood plain is the largest
(19,389 km2) and the most fertile sub region. It is primarily a
traditional rice-growing area. On medium lands, farmers used
to grow pulses such as grass pea, lentil, or Bengal gram in
winter, on residual moisture after harvest of long duration,
photosensitive local rice. Productivity and return of those
crops were low. However, due to introduction of high-yielding
36
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
potato–maize–rice, and potato–jute–rice systems, while
Ghosh and Malik (1999) reported such a build-up in a
rice–potato–sesame system.
Most of the previous work has focused on specific aspects
of R–W systems with a strong emphasis on yields and
nutrient management. Studies providing an integrated
assessment of more diversified, intensive double and triple
cropping systems have remained relatively rare in the
scientific literature, but they are needed for understanding
options for intensification and diversification in the IGP.
Here we present a quantitative assessment of nine intensive
cropping systems of the eastern IGP in terms of crop
productivity, profitability, energy use efficiency, soil fertility
and soil P and K balances. Due to uncertainties associated
with measuring all components of the N cycle, a discussion
of N balances was not included.
short duration rice in the 1970s and increasing irrigated area,
dry season rice replaced most pulses in this area. Crop
intensification and/or diversification has now further
increased with inclusion of short duration rapeseed and
potato in between wet season rice or jute and dry season rice,
resulting in higher production per unit area per unit time,
higher nutrient removal, and varying changes in soil fertility
as compared with rice–rice (R–R) and rice–wheat (R–W)
systems, the two predominant cropping systems of the IGP.
Most micro- and macro-level studies of cropping systems
in the IGP eco-region have focused on agronomic issues
related to R–W systems (Sarkar, 1997; Adhikari et al., 1999;
Yadav et al., 2000; Timsina et al., 2001; Bhandari et al., 2002;
Ladha et al., 2003). In the eastern IGP and similar areas,
several local studies have been conducted in the past to assess
various cropping systems in terms of productivity, profitability, energy efficiency, soil fertility and nutrient balances.
In one of these studies, for example, rice–wheat–jute was most
productive but had the lowest benefit: cost ratio, whereas rice–
mustard–sesame was least productive but had a high benefit:
cost ratio (R.C. Samui and A.L. Kundu, unpublished). In a
similar study, rice–potato–jute was the most productive and
profitable cropping sequence among five cropping sequences
tested (A.L. Kundu and R.C. Samui, unpublished). Mukhopadhyaya and Roy (2000) reported potato–jute–rice as a more
productive system than other systems such as potato–moong–
jute, potato–maize–rice and wheat–jute–rice.
Nutrient balances and trends in soil fertility also tend to
vary widely in the various intensive cropping systems of West
Bengal and other areas of the IGP. Timsina et al. (2006)
reported negative N balances, Saleque et al. (2006) negative P
balances, and Panaullah et al. (2006) negative K balances for
rice–wheat–maize and rice–wheat–mungbean sequences in
northwest Bangladesh, a region similar to the lower Gangetic
plain of the eastern IGP in west Bengal. Mandal et al. (1984)
and Saha et al. (2000) reported a decline in soil organic matter
under continuous jute–rice–wheat (J–R–W) cropping.
Mukhopadhyaya and Roy (2000) reported build-up of soil
organic carbon and available P and K in potato–moong–jute,
2. Materials and methods
2.1. Location, experimental design and treatments
A field experiment was conducted from 1999 to 2002
at the farm of the Zonal Adaptive Research Station,
Krishnagar, Nadia, West Bengal, India, located in the
Gangetic flood plain of the Eastern IGP (Lat. 238240 N, Long.
888310 E, Elev. 15 m a.s.l.). Prior to the experiment, the field
had been under irrigated R–W cropping for 5 years. The soil
of the experimental field is a very deep, well-drained, sandy
clay loam (Inceptisol) with 56% sand, 24% silt and 20% clay
in the surface layer (0–15 cm). Initial properties of a
composite soil sample collected at the beginning of the field
experiment were 4.6 g kg1 organic carbon (WalkleyBlack), 0.44 g kg1 total N (Kjeldahl), 24 kg ha1 available
P (Bray-1), 140 kg ha1 available K (1N NH4-acetate), and a
pH of 7.5 (1:2.5 soil: water).
The three cropping seasons at this site include a rainy or
kharif season from June to October, a winter or rabi season
from November to February, and a summer or dry season
Table 1
Weather at the experimental site in West Bengal, India
Cropping seasons
Wet/kharif (June–October)
Total rainfall (mm)
Evaporation (mm)
Average maximum
temperature (8C)
Average minimum
temperature (8C)
Average maximum
relative humidity (%)
Average minimum
relative humidity (%)
a
Winter/rabi (November–February)
Summer/dry (March–May)
99–00
00–01
01–02
LTAa
99–00
00–01
01–02
LTA
99–00
00–01
01–02
LTA
1450
526
31.6
1294
658
32.8
884
456
32.7
1137
544
32.9
81
412
26.2
0.0
306
28.4
26
297
27.4
58
338
28.5
253
384
33.1
205
259
34.3
244
342
34.2
236
328
36.6
25.5
30.6
25.7
25.0
12.5
14.3
13.5
13.5
23.0
22.5
22.5
22.5
96.5
95.6
92.5
93.8
97.8
98.2
94.7
95.0
89.6
96.6
91.9
90.3
78.9
76.1
74.4
81.0
53.0
44.0
51.3
59.3
51.2
54.0
50.0
48.0
LTA indicates long-term average.
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
from March to May (Table 1). Weather varied most among
the rainy seasons during the experimental period. Rainfall
during the rainy season always exceeds evaporation, while in
winter and dry seasons the reverse was the case. Maximum
temperatures are relatively stable throughout the year, but
minimum temperatures are lower in winter seasons than
in the other two seasons. Overall, weather during the
experimental period did not deviate much from the longterm averages (Table 1).
The experiment was laid out in a randomised complete
block design with 10 m 8 m plots replicated thrice. Nine
double- and triple-cropping systems were evaluated: rice–rice
(R–R), rice–wheat (R–W), rice–potato–rice (R–P–R), rice–
potato–sesame (R–P–S), rice–rapeseed–rice (R–Re–R), jute–
rice–rice (J–R–R), jute–wheat (J–W), jute–potato–rice (J–P–
R) and jute–rapeseed–rice (J–Re–R) (Fig. 1). These cropping
systems represent common traditional and recent cropping
systems in the eastern IGP. The experimental duration was 3
years, i.e., each cropping system was repeated three times,
resulting in 6–9 crops grown within 3 years.
2.2. Crop management practices and yield
measurements
37
of about 50 mm water per irrigation event. No irrigation was
applied to sesame. Pressure due to insect pests and diseases
was generally low for most of the seasons during the
experimental years. However, chemical protection measures
were taken against yellow stem borer (Tryporyza incertulas
Walker) in dry and late wet rice during all 3 years and in wet
rice during 2000–2001 and 2001–2002 and against rice bug
(Leptocoryza varicornis Thunberg) in wet and dry rice during
2000–2001. Chemical protection was also needed in jute
against stem weevil (Apion corchori Marshall) during 2000–
2001 and 2001–2002 and in rapeseed against aphid (Lipaphis
erysimi Kaltenbach) in all 3 years.
Yields of main and by-products of each crop under
various cropping systems were measured by hand-harvest of
a 20 m2 area in each plot at physiological maturity. The
economic part of individual crops was separated manually
after harvesting. Sub-samples of main product and byproduct were oven-dried to constant weight at 70 8C. All
crops were cut at about 15 cm from the surface, except
potato. Crop residues were removed for use as fuel, which
resembles the predominant farmers’ practice in this area.
Potato haulm was incorporated in the soil during harvesting.
2.3. Productivity, profitability, and energetics
Details of all cropping practices are given in Tables 2 and 3.
Land for all crops was prepared with a bullock drawn country
plough followed by laddering, while for rice puddling was
done prior to transplanting. Rice seedlings were 20 days old
for wet and late wet seasons and 40 days for dry season rice.
For all other crops, seeds were directly sown by hand. All
crops in the various cropping systems received recommended
doses of fertilizer (Table 2). Need-based irrigation was given
to each crop with ground water, with individual applications
Rice equivalent yield (REY) was calculated to compare
system performance by converting the yield of each crop
into equivalent dry season rice yield on a price basis, using
the formula:
REY ðof crop xÞ ¼ Yx ðPx =Pr Þ
where Yx is the yield of crop x (tons harvest product ha1), Px
the price of crop x, and Pr is the price of rice.
Fig. 1. Predominant cropping systems of West Bengal evaluated in the experiment.
38
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
Table 2
Management practices for individual crops grown in a field experiment in West Bengal, India
Number of
irrigationsb
Nutrient rate
(N–P–K,
kg ha1)c
Crop
Cultivar
Seed rate
(kg ha1)
Spacing
(cm)
Crop season
(seed to seed)a
Jute
JRO 524
5
25 5
April (1)–August (2)
1
50–11–21
Wet rice
MTU 7029
50
20 10
June (2)–October (1)
4
60–13–25
Late wet
rice
Wheat
Kalinga 3
75
15 10
August (1)–December (2)
4
40–9–17
UP 262
100
20 cont.
November (2)–March (2)
4
100–22–42
Potato
K-Ashoka
2500
45 20
November (2)–February (1)
6
200–43–125
Rapeseed
B-9
7
30 10
October (4)–February (2)
2
80–17–33
Dry rice
Kalinga 3
75
15 10
January (1)–April (2)
10
100–22–42
Sesame
Rama
9
30 10
March (1)–June (2)
0
50–11–21
Time of fertilizer
applicationc
Number of
weedings/
intercultural
operations
1/4 N + P + K at basal;
1/2 N at 15 DAS and
1/4 N at 30 DAS
1/2 N + P + K as
basal; 1/4 N at 21
DAS and 1/4
N at 40 DAS
1/2 N + P + K as basal
and 1/2 N at 21 DAS
1/2 N + P + K as basal
and 1/2 N at 21 DAS
1/4 N + P + K as basal;
1/2 N at 21 DAP and
1/4 N at 35 DAP
1/2 N + P + K as basal
and 1/2 N at 21 DAS
1/4 N + P + K as basal;
1/2 N at 21 DAT
and 1/4 N at 42 DAT
1/2 N + P + K as basal
and 1/2 N at 21 DAS
3
2
1
0
3
1
3
1
a
Figures in parenthesis indicate week of the month.
Need-based irrigation was given and the numbers of irrigations listed are averages of 3 years.
c
Nitrogen, phosphorus and potassium were applied as days after sowing (DAS) or planting (DAP) as urea, single super phosphate and muriate of potash,
respectively.
b
Prices of individual inputs and outputs were assumed to
be stable during the experimental period. Working out
production cost of individual crops from small experimental
plots was considered inaccurate. The Directorate of
Agriculture, Government of West Bengal (Anonymous,
1999) has surveyed costs for and returns from crops at
various locations within the state and set standard values for
input use and yields. Hence, we calculated the cost of
production on the basis of these standards. Family labor at
the mean wage rate of hired labor was included in the cost
calculations, thus ignoring possible opportunity costs. The
cost for harvesting and processing also depends on the
amount of yield. Therefore, cost per unit yield for harvest
and processing was calculated using measured mean yields
for individual crops under various cropping systems tested in
combination with the published standard costs for harvesting
Table 3
Input requirements of the individual crops grown
Item
Wet rice
60
Fertilizer-N (kg ha1)
Fertilizer-P (kg ha1)
13
25
Fertilizer-K (kg ha1)
Seed (kg ha1)
50
Endosulfan (L ha1)
Carbendazim (kg ha1)
0.83
Mancozeb (kg ha1)
Dimethoate (L ha1)
0.75
Carbofuron 10 G (kg ha1)
Irrigation (mm ha1)
200
5
Diesel (L ha1)
Bullock pair (h ha1)
32
Labor before harvest
Men (8-h days ha1)
77
Women (8-h days ha1)
39
Labor for harvest and processing
Men (8-h days ha1)
96
50
Women (8-h days ha1)
Late wet rice
40
9
17
75
Dry rice
Wheat
100
22
42
75
100
22
42
100
Jute
Potato
50
11
21
5
1
200
43
125
2500
6.25
0.75
1.50
200
5
32
0.75
1.50
500
7
32
Rapeseed
80
17
33
7
Sesame
50
11
21
9
0.02
1.88
0.50
200
5
24
50
15
24
300
5
32
100
5
24
5
24
77
39
99
51
45
23
100
51
103
53
43
22
20
10
96
50
106
55
23
12
101
51
67
34
40
21
17
9
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
39
Table 4
Production costs (Rs. ha1) of the crops grown in the various cropping systems evaluated
Item
Wet rice
Late
wet rice
Dry rice
Wheat
Jute
Potato
Rapeseed
Sesame
Land preparation
Seed
Fertilizer
Pesticides
Irrigation
Depreciation
Tax
Labor before harvest
Total cost
before harvest
Mean yield (t ha1)a
Cost for harvest
and processing
Rs. ha1
Rs. t1 yield
Total cost at Y
ton yield
level (Rs. ha1)
1856
500
1681
95
267
224
17
3730
8369
1856
750
1120
190
267
224
17
3730
8154
1750
750
2972
165
3063
271
18
5251
14240
1908
1000
2324
0
173
277
18
2157
7857
2379
250
1270
148
338
283
21
5460
10149
2588
4500
6627
1039
1993
1124
652
5290
23813
940
120
2207
84
449
296
22
2284
6402
1800
90
1675
166
0
90
17
1050
4888
4.26
3.08
5108
1198
8369
+ 1198Y
5108
1658
8154
+ 1658Y
4.88
5605
1148
14240
+ 1148Y
3.36
5504
1636
7857
+ 1636Y
2.80
5330
1904
10149
+ 1904Y
25.62
3527
138
23813
+ 138Y
1.18
2128
1811
6402
+ 1812Y
1.10
875
796
4888
+ 796Y
1 US $ = Indian Rupees (Rs.) 48.
a
Mean yield of a crop obtained under individual cropping systems in the experiment.
and processing of individual crops. A summary of
production costs by crops is shown in Table 4. Net return
or profit was calculated by subtracting production cost from
the gross value of the produce, including by-product value or
gross return. Prices used for harvest products were average
prices observed during the experimental period. The benefit:
cost ratio (BCR) was calculated by dividing the net return by
the production cost for individual crops and for various
systems.
To study energy inputs and outputs of individual cropping
systems, a complete inventory of all crop inputs (fertilizers,
seeds, plant protection chemicals, fuels, human labor and
animal power) and outputs of both main and by-products
was prepared. The energy value of each cropping system
was determined based on energy inputs and energy
production for the individual crops in the system. Inputs
and outputs were converted from physical to energy unit
measures through published conversion coefficients. Component energy inputs for raising various crops are given in
Table 5. Energy output was calculated on both economic
yield (=sellable harvest product) and biological yield (=total
dry matter produced) basis. Average annual energy use
efficiency (EUE = energy output/energy input) and energy
productivity (EP = yield/energy input) were calculated for
each cropping system.
2.4. Soil, plant and water analysis
To study changes in soil fertility status, initial soil
samples were collected with an auger for the 0–15 cm soil
Table 5
Component energy inputs (MJ ha1) for raising various crops evaluated in a field experiment in West Bengal, India
Operation/source
Land preparation
N-fertilizer
P-fertilizer
K-fertilizer
Seed
Pesticides
Irrigation
Labor before harvest
Labor for harvest and
processing (MJ t1
main product)
Total energy
requirement at
Y t ha1 yield
level (MJ ha1)
Wet rice
Late wet rice
Dry rice
Wheat
Potato
Jute
Rapeseed
Sesame
1318
3636
333
201
588
189
3200
1482
438
1318
2424
222
134
882
378
3200
1482
606
1318
6060
555
335
735
15
8000
1920
420
988
6060
555
335
1470
120
3200
862
130
1318
12120
1110
1005
9513
750
4800
1934
50
988
2424
222
268
929
120
800
1996
695
988
4848
444
268
145
288
1600
835
662
988
3030
275
168
263
0
800
383
289
10946
+ 438Y
10039
+ 606Y
18938
+ 420Y
13590
+ 130Y
32649
+ 50Y
6910
+ 695Y
9416
+ 662Y
5907
+ 289Y
40
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
depth at 20 locations of the experimental area. The samples
were thoroughly mixed, dried and passed through 2 mm
sieve and kept in poly bags for chemical analysis of organic
carbon, pH (1:2.5 soil: water), total N, available K (1N NH4acetate) and available P (Bray-1). Soil samples were also
taken and analyzed treatment wise after harvest of each crop
in each year under individual cropping systems. Plant
samples were taken at physiological maturity for rice, wheat
and sesame, and at harvest for potato and jute during each
cropping season for the determination of P (Spectrophotometer method) and K (Flame photometer method) in
economic and by-product parts of the plant. In jute, wholeplant samples were analyzed for P and K, but in potato, only
tubers were analyzed. Crop uptake of P and K was estimated
by multiplying the dry matter yields (after drying at 70 8C to
constant weight) of each crop with their corresponding
nutrient contents. Nutrient contents in irrigation and rain
water during each cropping season, and in seeds of
individual crops and in potato tubers were measured using
the standard procedures. Average (of 3 years) P and K
contributions through rainwater were 0.0013 and
0.0333 kg ha1 cm1, respectively, and through irrigation
water were 0.008 and 0.16 kg ha1 cm1, respectively.
practice. Roots and stubbles of previous crops and weed
biomass were fully removed so that their nutrient contributions to apparent balances were almost nil. Average seasonal
rainfall received and irrigation water applied were 806 and
50 mm for jute, 1084 and 200 mm for wet rice, 613 and
200 mm for late wet rice, 36 and 200 mm for wheat, 21 and
300 mm for potato, 36 and 100 mm for rapeseed, 68 and
500 mm for dry rice, and 450 and 0 mm for sesame. The P
and K contributions through rain and irrigation water during
each crop season were estimated by multiplying their
respective concentrations with the amount of rain received
and irrigation water applied over the season. The P
contribution through both rainfall and irrigation was
minimal (0.1–0.8 kg ha1), compared to K (2.8–
16.0 kg ha1), and that P and K inputs through rainfall
was much smaller (0.1–5.2 kg ha1) than irrigation (0.2–
16.0 kg ha1). We assumed that there would be no loss of P
through leaching or other wise from the soil system
(Dobermann et al., 1996a). Leaching loss of K for all crops
was assumed to be 150 g kg1 of K input (Smaling and
Fresco, 1993).
3. Results and discussion
2.5. P and K uptake and balances
3.1. Productivity
Apparent balances of P and K were estimated after 3
years under individual cropping systems as
X
P balance ¼
ðfertilizer P; rain P; irrigation-water P;
X
P in seedlings and seedsÞ Crop P removal
X
K balance ¼
ðfertilizer K; rain K; irrigation-water K;
X
K in seedlings and seedsÞ ðCrop K removal;
leaching losses of KÞ
Fertilizer inputs to various crops were made as per the
recommendation of the Department of Agriculture, Government of West Bengal (Anonymous, 1998). No manure was
applied to any crop, resembling the majority of the farmers’
Crops yields in the individual cropping systems varied by
climatic seasons and, within the same climatic season, were
much affected by the previous crop grown (Table 6). In the
rainy season, yield of rice tended to be higher (4.6–
4.7 t ha1) in R–P–R and R–P–S systems than in R–R, R–W,
or R–Re–R systems (4.0–4.1 t ha1). Jute grown in the J–P–
R system recorded higher fiber yield (3.2 t ha1) than that
from other jute-based systems (2.7 t ha1). In winter
seasons, yield of potato grown in the J–P–R rotation
averaged 28.8 t ha1 as compared to 23.7–24.4 t ha1 in R–
P–R and R–P–S systems. Yield of all winter crops was
higher after jute than following rice. Yield of dry season rice
following potato was higher (5.4–5.6 t ha1) than that of rice
Table 6
Mean crop productivity and rice equivalent yield (REY) of various cropping systems evaluated in a field experiment in West Bengal, India
Cropping system
R–R
R–W
R–P–R
R–P–S
R–Re–R
J–R–R
J–W
J–P–R
J–Re–R
CD (5%)
Yield (t ha1)
System-wise REY (t ha1)
Rainy
Winter
Summer
99–00
00–01
01–02
Pooled
4.09
3.97
4.65
4.63
3.98
2.68
2.76
3.18
2.58
–
3.01
24.35
23.72
1.06
3.08
3.72
28.79
1.29
4.58
–
5.40
1.10
4.29
5.00
–
5.63
4.40
8.99
7.30
22.01
19.94
10.86
13.29
9.21
26.33
12.14
7.00
7.18
21.44
19.21
10.62
10.21
8.85
24.07
11.91
8.79
8.89
21.82
17.13
9.78
8.52
9.14
23.05
9.22
8.26g
7.79g
21.76b
18.76c
10.42de
10.67d
9.07f
24.49a
11.09d
0.68
0.85
1.10
0.49
R, rice; W, wheat; P, potato; S, sesame; Re, rapeseed; J, jute. Means of pooled REY followed by the same letter do not significantly differ (P < 0.05).
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
following rapeseed or rice (4.3–5 t ha1). When the systemwise REY was considered, cropping systems including
potato recorded greater overall production (REY = 19–
25 t ha1) than any other systems (8–11 t ha1). Among the
potato-inclusive systems ranking in terms of total productivity followed the order J–P–R > R–P–R > R–P–S. Other
triple cropping systems that did not include potato recorded
intermediate system REY, whereas the three double
cropping systems (R–R, R–W and J–W) had the lowest
annual productivity.
In the potato-containing triple-cropping systems, rice
yields following potato were significantly higher than when
grown after rice or rapeseed. Residual effects of high doses of
fertilizer applied to potato as well as intensive soil aeration
during potato cropping may have caused benefits for rice, as
has also been observed in other studies with potato systems
(Biswas and Mitra, 1987). Jute also appears to have beneficial
effects on succeeding crops (Mandal et al., 1981; CRIJAF,
2000), which may be associated with improvements in
nutrient cycling, soil structure, and root growth. Jute itself
may perform better in a J–W system than in a J–R–R system
(Tomar and Tiwari, 1990), partly because the dissimilar
nature of crops in the J–W system results in better overall
nutrient use efficiency. Rice and wheat are more nutrient
exhaustive crops than jute and growing two rice crops in a J–
R–R system exhausts more nutrients than a single crop of
wheat in a J–W system. Low grain yields of cereals grown
after nutrient exhausting crops such as rapeseed or mustard
have also been observed in other studies (Singh and Beniwal,
1983). Poor performance of wet season rice in R–R and R–
Re–R systems was probably due to growing two rice crops in
quick succession (Gangwar et al., 1986). Poor performance of
late wet season rice was caused by delayed transplanting,
which can result in cold damage during flowering stage of
rice. Also, late wet season rice suffered from some insect and
diseases damage. Jute had positive residual effects on wheat
grown thereafter because it left the soil with better physical
structure than when wheat was grown after rice. Presence of a
individual crop species in the rotation generally reduced pest
pressure on wheat (data not shown).
41
3.2. Profitability
Both production costs and annual net returns must be
considered for choosing suitable cropping systems for the
IGP because those varied widely among individual cropping
systems (Table 7). In the wet season, production cost was
15% higher for jute (Rs. 15,500 ha1) than rice (Rs.
13,500 ha1). In summer, sesame had much lower production cost (Rs. 6000 ha1) than rice (Rs. 20,000 ha1). In
winter, production cost was highest for potato (Rs.
27,000 ha1), intermediate for wheat (Rs. 13,000 ha1)
and least for rapeseed (Rs. 8000 ha1). Production cost of
rapeseed was lowest due to its low labor and less land
preparation requirement. Production cost for wheat was also
low due to its low labor requirement. Annual production
costs increased with increasing cropping intensity, with
triple cropping systems incurring considerably higher costs
than double-cropping systems. Inclusion of potato in triple
cropping systems resulted in significantly higher production
costs than that of any other systems, primarily due to high
costs for tuber, fertilizer, land preparation, irrigation and
plant protection (Table 4). Double-cropping systems such as
R–W and J–W had the lowest annual production costs.
Net returns were directly related to the price that the
producer received for the product and inversely related to the
production cost. Though growing potato was associated with
the highest production cost, it was also the most profitable
crop. Both net return and BCR were highest for potato as well
as for potato containing cropping systems than for other crops
and systems, mainly due to higher yield of potato. Among all
potato-based systems, economic performance of potato after
jute in J–P–R system was the best in terms of both net return
and BCR (Table 7). In contrast, the lowest BCR was observed
for late wet season rice under J–R–R and for rapeseed under
R–Re–R cropping systems. Though sesame produced somewhat lower return, it recorded the highest BCR due to its
lowest cost of production particularly for seed, labor and plant
protection. Despite the fact that R–R and R–W had lower
production costs, net returns from these systems were also the
lowest because of the low annual crop production. J–R–R and
Table 7
Economic return of various cropping systems evaluated in a field experiment in West Bengal, India
Cropping system
Production cost (Rs. ha1)
Net return (Rs. ha1)
Benefit cost ratio
Rainy
Winter
Summer
System
Rainy
Winter
Summer
System
Rainy
Winter
R–R
R–W
R–P–R
R–P–S
R–Re–R
J–R–R
J–W
J–P–R
J–Re–R
13269
13129
13935
13911
13137
15257
15403
16209
15054
0
12780
27165
27078
8321
13262
13936
27777
8730
19497
0
20442
5759
19168
19975
0
20706
19287
32766
25909
61543
46749
40625
48494
29339
64692
43070
10720
10315
13191
13272
10100
9673
10237
13218
8826
0
12390
33702
32214
6387
5998
17360
44206
9253
8999
0
12981
9560
7472
10881
0
14220
8013
19719
22704
59874
55046
23959
26552
27598
71645
26092
0.81
0.79
0.95
0.95
0.77
0.63
0.66
0.82
0.59
0.97
1.24
1.19
0.77
0.45
1.25
1.59
1.06
CD (5%)
399
262
265
503
1285
1735
1179
2482
0.06
0.09
1 US $ = Rs. 48.
Summer
System
0.46
0.69
0.42
0.60
0.88
0.97
1.18
0.59
0.55
0.94
1.11
0.61
0.09
0.05
0.64
1.66
0.39
0.54
42
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
J–W cropping systems gave intermediate returns due to high
production cost of jute and lower market prices of rice and
wheat. It should be noted, however, that the average
production costs and economic returns shown in Table 7
only illustrate the major differences among cropping systems.
Annual price fluctuations are likely to cause significant
variation in the economic performance and also varying
economic risk among the systems.
3.3. Energetics
The total annual energy input in individual cropping
systems ranged from about 23,000 MJ ha1 in J–W to 68,000
MJ ha1 in R–P–R cropping system (Table 8). In winter,
potato required more energy (34,000 MJ ha1) than
wheat (14,000 MJ ha1) or rapeseed (10,000 MJ ha1).
In summer, the energy requirement for rice (21,000
MJ ha1) was much higher than for growing sesame
(6000 MJ ha1). Energy requirement for the production
of wet season rice was higher (13,000 MJ ha1) than that of
jute (9000 MJ ha1) due to higher energy expenditure in
rice for land preparation, nitrogen fertilization and irrigation,
in spite of higher labor requirement for jute.
Annual energy input was generally higher in triplecropping systems (40,000–68,000 MJ ha1) than in doublecropping systems (23,000–34,000 MJ ha1), but triplecropping systems also produced more energy through both
greater economic (saleable harvest products) and biological
yields (total dry matter production) than the doublecropping systems did (Table 8). The lowest energy output
in terms of both economic and biological yield occurred in
R–W and J–W cropping systems, while the highest energy
output was estimated for triple-crop systems that included
potato and/or jute, e.g., J–P–R, R–P–R, and J–R–R. In all
cropping systems, nitrogen fertilizer accounted for the
largest share of total energy input (26–37%) followed by
irrigation (17–33%, Table 9). Energy embedded in N
fertilizer was particularly high in the three triple-cropping
systems with potato, which also had relatively large
components of energy in seed and labor (Table 9).
All systems produced more energy than what was
required for annual crop production, but the system-wise
energy use efficiency varied from 3.3 to 4.5 MJ MJ1 on
economic yield basis or from 5.9 to 11.2 MJ MJ1 on
biological yield basis. The EUE was highest for J–W, J–R–R
and R–W systems, both in terms of economic and biological
yield (Table 8). It was relatively low in cropping systems
with potato because of the large energy input associated with
growing this crop. Energy productivity was highest for J–P–
R (583 g MJ1) followed by R–P–S (554 g MJ1) and R–P–
R (505 g MJ1), primarily due to the high yield of potato in
these cropping systems. R–Re–R (214 g MJ1) and J–Re–R
(208 g MJ1) recorded the lowest energy productivity,
mainly because of low yield of rapeseed.
Wet season rice required more energy input and also
produced more energy output than jute, but jute was more
energy efficient than rice because of comparatively lower
energy requirement. However, in terms of converting solar
radiation into dry matter (i.e., energy productivity) both rice
and jute were not very productive crops. Among the winter
crops, potato was the highest energy producer and the
highest energy consumer, resulting in low energy efficiency
but still with the highest energy productivity. Energy use
efficiency of wheat, on the other hand, was higher than that
of potato because of lower energy requirement. All winter
crops grown after jute recorded greater energy output than
those following rice. Dry season rice required more energy
inputs than summer sesame, primarily because of greater
energy requirements for field operations, plant nutrients and
irrigation. Energy output was also higher in dry season rice
than in sesame but energy use efficiency was the reverse.
Among various systems, J–W was the most energy
efficient while R–Re–R was the least efficient in terms of
economic yield. Though cropping systems involving potato
produced higher energy output, their high-energy consumption resulted in lower energy use efficiency. Jute under
Table 8
Energy use efficiency of various cropping systems evaluated in a field experiment in West Bengal, India
Cropping Energy input (MJ ha1)
system
Energy output (MJ ha1)
Economic yield (EY)
Rainy
Winter Summer System Rainy
R–R
R–W
R–P–R
R–P–S
R–Re–R
J–R–R
J–W
J–P–R
J–Re–R
12738
12686
12981
12973
12689
8775
8828
9122
8700
0
13980
33876
33844
10117
11907
14072
34100
10267
20858
0
21203
6296
20738
21033
0
21300
20781
33596
26667
68060
53113
43544
41714
22900
64522
39749
CD (5%)
232
289
243
705
a
b
Winter
6849
5452
Biological yield (BY)
Summer System Rainy
60123
0 67326
58408 44247
0
68306 92761 79429
68012 90361 31996
58506 21928 63112
48032 45276 73451
49404 54635
0
56982 109703 82810
46122 26606 64631
6887
EPb (g MJ1)
EUE a
127449
102655
240496
190368
143546
166759
104039
249494
137360
10451
Winter
10623
BY
Summer System
129915
0 137284
127950 95497
0
146014 92761 159512
147554 90361 76051
125089 55611 127779
131012 93526 146868
134724 120635
0
153417 109703 167310
125007 69788 131089
10283
EY
9218
267199
223447
398287
313965
308479
371405
255359
430429
325885
3.79 7.95 258
3.85 8.38 262
3.53 5.85 505
3.58 5.91 554
3.30 7.08 214
4.00 8.90 258
4.54 11.15 283
3.87 6.67 583
3.46 8.20 208
15347 0.18
0.42
15
Energy use efficiency for economic (EY, saleable harvest product) and biological yield (BY, total dry matter produced). EUE = energy output/energy input.
Energy productivity.
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
43
Table 9
Energy input components of various cropping systems evaluated in a field experiment in West Bengal, India
Component
Cropping system
R–R
(MJ ha1)
R–W
(MJ ha1)
R–P–R
(MJ ha1)
R–P–S
(MJ ha1)
R–Re–R
(MJ ha1)
J–R–R
(MJ ha1)
J–W
(MJ ha1)
J–P–R
(MJ ha1)
J–Re–R
(MJ ha1)
Land preparation
N-fertilizer
P-fertilizer
K-fertilizer
Seed
Pesticides
Irrigation
Labor before harvest
Labor for
harvest/processing
2636
9696
888
536
1323
204
11200
3402
3711
2306
9696
888
536
2058
309
6400
2344
2130
3954
21816
1998
1541
10836
954
16000
5336
5625
3624
18786
1718
1374
10364
939
8800
3799
3709
3624
14544
1332
804
1468
492
12800
4237
4243
3624
10908
999
737
2546
513
12000
5398
4989
1976
8484
777
603
2399
240
4000
2858
1563
3624
20604
1887
1608
11177
885
13600
5850
5287
3294
13332
1221
871
1809
423
10400
4751
3648
Total energy input
33596
26667
68060
53113
43544
41714
22900
64522
39749
Component
Cropping system
R–R
R–W
R–P–R
R–P–S
R–Re–R
J–R–R
J–W
J–P–R
J–Re–R
(% of total) (% of total) (% of total) (% of total) (% of total) (% of total) (% of total) (% of total) (% of total)
Land preparation
N-fertilizer
P-fertilizer
K-fertilizer
Seed
Pesticides
Irrigation
Labor before harvest
Labor for harvest/processing
7.8
28.9
2.6
1.6
3.9
0.6
33.3
10.1
11.0
8.6
36.4
3.3
2.0
7.7
1.2
24.0
8.8
8.0
5.8
32.1
2.9
2.3
15.9
1.4
23.5
7.8
8.3
6.8
35.4
3.2
2.6
19.5
1.8
16.6
7.2
7.0
8.3
33.4
3.1
1.8
3.4
1.1
29.4
9.7
9.7
8.7
26.1
2.4
1.8
6.1
1.2
28.8
12.9
12.0
8.6
37.0
3.4
2.6
10.5
1.0
17.5
12.5
6.8
5.6
31.9
2.9
2.5
17.3
1.4
21.1
9.1
8.2
8.3
33.5
3.1
2.2
4.6
1.1
26.2
12.0
9.2
R, rice; W, wheat; P, potato; S, sesame; Re, rapeseed; J, jute.
J–P–R was the least energy efficient crop though most
energy productive. Likewise, rice under R–R, R–W and R–
Re–R was also the least energy efficient crop. Of all cropping systems, R–W, J–W and R–R had lowest energy output.
Low energy output in R–W systems was also reported by
Subbian et al. (1995) and Parihar et al. (1999).
3.4. Soil fertility
Cropping system affected soil quality in terms of pH, EC,
SOC, available P, available K and total N (Table 10). Soil pH
declined in all cropping systems from initially 7.4 to 6.9 to
7.2 after 3 years of cropping, but treatment differences were
not significant (Table 10). Such decreases in pH have also
been reported in other studies with similar cropping systems
(Mandal and Pal, 1965; Sadanandan and Mhapatra, 1972).
Mechanisms causing the decrease in soil pH may vary
among the crops and cropping systems evaluated. In soils
with pH > 7, long periods of flooding such as found in two
rice crops grown per year are likely to cause a decline in pH
during the flooded phase due to changes in the CO2
equilibrium in soil solution and also due to rhizosphere
acidification in the root zone (Kirk, 2004). After rice, drying
out of the soil leads to re-oxidation of reduced substances
Table 10
Soil fertility status after 3 years of experimentation under individual cropping systems
System
pH
EC (dS m1)
Organic C (g kg1)
Total N (g kg1)
Available P (kg ha1)
Available K (kg ha1)
R–R
R–W
R–P–R
R–P–S
R–Re–R
J–R–R
J–W
J–P–R
J–Re–R
7.1
7.2
6.9
7.0
6.9
7.1
7.2
6.9
7.0
0.15b
0.24a
0.22a
0.22a
0.17b
0.15b
0.23a
0.23a
0.16b
3.6c
3.9bc
5.1a
5.0a
3.9bc
5.0a
4.8a
5.5a
4.6b
0.42bc
0.41c
0.47b
0.46b
0.39
0.47b
0.50ab
0.55a
0.46b
20.2c
20.0c
28.2ab
26.2b
19.0c
26.4b
27.2b
32.2a
26.2b
122cd
118cd
148b
149b
110d
142b
149b
175a
133bc
Initial value
CD (5%)
7.4
NS
0.20
0.03
4.6
0.8
0.44
0.06
24.0
4.4
Within each column, means followed by the same letter do not significantly differ (P < 0.05).
140
17
44
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
such as ferrous iron and sulfides, which may also cause a
decrease in pH. In crops or systems with greater soil aeration
and high N fertilizer rates, nitrification is likely to be a major
source of soil acidification. Of the systems compared here,
triple-crop systems containing potato may have been most
affected by this.
Soil EC increased in systems with potato and wheat,
irrespective of whether rice and jute were grown, and
decreased under R–R, R–Re–R, J–R–R and J–Re–R
systems. Rice generally resulted in lowering of EC
irrespective of season of its cultivation and cropping
systems. Soil EC is often related to soluble salts such as
nitrate and the concentration of those is much affected by N
fertilizer use and N losses due to leaching and denitrification
(Smith and Doran, 1996). Wet cultivation practices in sandy
loam soil probably caused nitrate and sulfate losses from the
soil, resulting in lower EC after rice. Under upland crops,
nitrate was likely to be major form of soil mineral N,
resulting in higher EC, particularly in crops with high N use
such as potato or wheat (Table 9). Overall, however, soil EC
levels (0.15–0.24 dS m1) remained well below levels that
could cause any harm to crops.
Generally, organic carbon, total N, available P, and
available K in soil tended to increase in systems with either
jute or potato. More specifically, soil organic carbon, total
soil N and available P increased in J–P–R, J–R–R, R–P–R,
R–P–S, and J–W systems, but decreased in R–R, R–W, and
R–Re–R after three annual cycles (Table 10, Fig. 2). With
the exception of J–P–R, available soil K decreased (R–W,
R–R, R–Re–R) or remained unchanged in all cropping
systems (Fig. 2), primarily due to nearly complete removal
of K-rich vegetative biomass in these intensive cropping
systems (see below). The decline in organic carbon,
particularly in R–R and R–W systems, raises concern about
the sustainability of these systems in terms of maintaining
food security in the IGP as these are the predominant
systems in the region. Declining availability or use of
farmyard manure, continuous cropping, removal of crop
residues and excessive tillage are the main causes of the
decrease in soil organic matter in many rice-based
cropping systems of south Asia (Nambiar, 1994; Yadvinder-Singh et al., 2005). Soil drying and enhanced soil
aeration during fallow periods facilitate faster decomposition of crop residues and soil organic matter in double- or
triple-cropping systems with either long or dry fallow
periods or with upland crops in the rotation (van Gestel
et al., 1993; Witt et al., 2000). In our study, however,
organic matter increased considerably after jute and potato,
irrespective of cropping systems. This might be due to
greater rhizodeposition and leaf shedding of jute throughout its growth period and due to the incorporation of potato
haulm at harvest, both contributing to an increase in
organic carbon. Increases in organic matter in jute-based
system (Chatterjee et al., 1978) and in rice–potato–sesame
cropping system (Ghosh and Malik, 1999) have also been
observed in West Bengal.
Fig. 2. Changes in soil organic carbon and available soil P and K under
individual cropping systems.
3.5. P and K budgets
Fertilizer was the dominant source of P input, with minor
contributions from rain and irrigation water and from seed
material. Total annual P output ranged from 33 to 75 kg ha1
(Table 11). Average annual P balances ranged from
24 kg ha1 yr1 in J–R–R to +25 kg ha1 yr1 in R–P–
S. Other cropping systems, such as R–P–R, R–W, R–Re–R,
and J–P–R exhibited positive balances, while J–W, J–Re–R
and R–R exhibited slightly negative balances (Table 11).
The negative P balances probably explained the decline in
available P in R–R (Fig. 2). In R–W and R–Re–R systems,
available P declined despite of a slightly positive P balance.
The most likely explanation for this is a decrease in soil P
availability due to alternating aerobic–anaerobic periods and
their influence on the dynamics of Fe and Ca-phosphates in
soil (Sah and Mikkelsen, 1986; Willett and Higgens, 1978;
Yadvinder-Singh et al., 2000). Of the systems compared,
uneconomical excessive P additions only occurred in the R–
P–R and R–P–S systems, primarily due to high rates (43 kg
P ha1) of P application to potato.
Fertilizer was also the dominant source of K input, with
significant contribution from irrigation water, and minor
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
45
Table 11
Average annual P input–output balance of the cropping systems evaluated
System
Inputs
Output
Balance
Fertilizer
Rainfall
Irrigation
Seed
Total
Crop removal
R–R
R–W
R–P–R
R–P–S
R–Re–R
J–R–R
J–W
J–P–R
J–Re–R
34.4
34.4
77.4
66.7
51.6
40.9
32.3
75.3
49.5
0.1
0.1
0.2
0.2
0.2
0.2
0.1
0.1
0.1
0.6
0.3
0.8
0.4
0.6
0.6
0.2
0.7
0.5
0.6
0.6
2.2
1.9
0.6
0.6
0.3
1.9
0.3
35.7
35.4
80.5
69.1
53.0
42.2
32.9
78.0
50.4
39.7
32.5
59.9
44.3
47.2
66.3
44.5
75.0
58.0
4.0
2.9
20.6
24.8
5.8
24.1
11.6
3.0
7.6
CD (5%)
0.2
1
All values are in kg P ha
per year.
Table 12
Average annual K input–output balance of the cropping systems evaluated
System
R–R
R–W
R–P–R
R–P–S
R–Re–R
J–R–R
J–W
J–P–R
J–Re–R
Inputs
Outputs
Balance
Fertilizer
Rainfall
Irrigation
Seed
Total
Crop removal
Losses
Total
66.4
66.4
190.9
170.2
99.6
78.9
62.3
186.8
95.5
3.8
3.7
3.9
5.2
4.0
5.0
2.8
3.0
3.0
11.2
6.4
16.0
8.0
12.8
12.0
4.0
13.6
10.4
4.6
2.6
11.2
9.0
4.6
4.7
0.4
9.0
2.4
86
79
222
192
121
101
70
212
111
166
142
248
185
180
251
170
289
213
24
24
54
47
36
29
23
53
35
190
166
302
231
216
279
192
342
248
CD (5%)
104
87
80
39
95
179
123
130
136
11
1
All values are in kg K ha
per year.
contributions from rain water and seed material. Total
annual crop K removal ranged from 142 to 289 kg ha1, but
estimated K losses of 23–54 kg ha1 (Table 12) remain quite
uncertain due to the lack of measurements of leaching losses
in the present study. The apparent average annual K balances
were all negative and ranged from 179 kg ha1 yr1 in J–
R–R to 39 kg ha1 in R–P–S (Table 12). R–W had a
negative K balance of 87 kg ha1 and R–P–R had negative
balance of 80 kg ha1. These results confirmed the declining
trends in available soil K in many treatments (Fig. 2) and
they are comparable with many other long-term studies in
R–R and R–W systems of Asia (Dobermann et al., 1996b;
Ladha et al., 2003). One major exception was the J–P–R
system in which available soil K measured in 0–15 cm depth
increased over time (Fig. 2) despite a highly negative annual
K balance of 130 kg ha1 (Table 12). The most likely
explanation for this apparent discrepancy is that redistribution of K from greater soil depths occurred in this
system, i.e., extraction of soil K by crops with a deeper root
system and deposition near the surface through crop
residues. This system was the only one with significant
increases in SOC, available P, and available K over time
(Fig. 2). Regardless of this exception, it remains obvious that
improvements in K management considering crop require-
ment, soil nutrient supply, long-term fate of added fertilizer,
and the overall input/output balance must be made to
maintain the productivity of intensive cropping systems in
West Bengal.
4. Conclusions
There is potential for greater adoption of intensified
cropping systems with increased productivity and energy
efficiency as compared to rice–wheat or rice–rice systems in
the Eastern IGP. Diversified triple cropping systems such as
rice–potato–rice, rice–potato–sesame and jute–potato–rice
had high cost, but also highest annual yield, net return, benefit:
cost ratio, and energy productivity. Compared to R–R or R–W,
potato and/ or jute inclusive cropping systems also maintained
or improved soil organic matter and P status. Negative K
balances and declines in available soil K in many of the
cropping systems studied data indicate inadequacy of present
recommended rates of fertilizer-K for all component crops of
the systems studied, whereas P recommendations seem
adequate. Considering all this, triple cropping systems
involving potato appear to be most suitable for resourcerich large farmers. Steady expansion of potato area and
46
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
production after rice and jute has already occurred in the
eastern IGP in spite of strong price seasonality and higher risk.
Whether this process continues remains to be seen and will
also depend on factors such as prices and cold storage
availability. The main harvest of potato in the eastern IGP
occurs in February and March. Temperatures rise steadily
until the onset of the southwest monsoon in June. Traditional
storage is not an effective option from mid-April onwards, but
prices continue to rise until the rainy season crop is harvested
in October. Recent public and private sector initiatives have
focused on increasing the cold storage area, expansion of
potato exports and diversified processing, thus reducing the
risk of price decline and improving the overall potato market.
Compared to triple-crop system with potato, systems such as
jute–wheat, jute–rapeseed–rice, and rice–wheat require fewer
inputs and are also less risky, which probably makes them
more suitable for resource-poor small farmers.
References
Adhikari, C., Bronson, K.F., Panaullah, G.M., Regmi, A.P., Saha, P.K.,
Dobermann, A., Olk, D.C., Hobbs, P., Pasuquin, E., 1999. On farm soil
N supply and N nutrition in the rice–wheat system of Nepal and
Bangladesh. Field Crops Res. 64, 273–286.
Anonymous, 1998. Soil Test-based Fertilizer Recommendations for Principal Crops and Cropping Sequences in West Bengal. Department of
Agriculture, Government of West Bengal.
Anonymous, 1999. Study on Farm Management and Cost of Production of
Crops in West Bengal, 1995–96, Evaluation Wing, vol. XXXVIII.
Directorate of Agriculture, Government of West Bengal, Calcutta.
Bhandari, A.L., Ladha, J.K., Pathak, H., Padre, A.T., Dawe, D., Gupta, R.K.,
2002. Yield and soil nutrient changes in a long-term rice–wheat rotation
in India. Soil Sci. Soc. Am. J. 66, 162–170.
Biswas, G.C., Mitra, P.C., 1987. Residual effect of fertilizers applied to
potato and rice on the yield of jute fibre in rice–potato–jute cropping
sequence. Jute Dev. J. 7 (1), 43–53.
Chatterjee, B.N., Banerjee, N.C., Ghosh, D.C., Debnath, P.K., 1978.
Response to P, K and FYM in multiple cropping with potato. J. Ind.
Potato Assoc. 5, 9–12.
CRIJAF (Central Research Institute of Jute and Allied Fibre), 2000. Annual
Report for 1999–2000, pp. 79–84.
Dobermann, A., Cassman, K.G., Sta. Cruz, P.C., Adviento, M.A.A., Pampolino, M.F., 1996a. Fertilizer input, nutrient balance, and soil nutrient
supplying power in intensive, irrigated rice systems. III. Phosphorus.
Nutrient Cycl. AgroEcosyst. 46, 111–125.
Dobermann, A., Sta.Cruz, P.C., Cassman, K.G., 1996b. Fertilizer inputs,
nutrient balance, and soil nutrient supplying power in intensive, irrigated rice systems. I. Potassium uptake and K balance. Nutrient Cycl.
Agroecosyst. 46, 1–10.
Gangwar, S.K., Chakraborty, S., Dasgupta, M.K., Huda, A.K.S., 1986.
Modeling yield loss in Indica rice in farmers’ fields due to multiple
pests. Agric. Ecosyst. Environ. 17, 165–171.
Ghosh, D.C., Malik, G.C., 1999. Fertility management in potato under
potato–sesame–rice cropping system. Environ. Ecol. 17, 643–645.
Kirk, G.J.D., 2004. The Biogeochemistry of Submerged Soils. Wiley, New
York.
Ladha, J.K., Dawe, D., Pathak, H., Padre, A.T., Yadav, R.L., Singh, B.,
Singh, Y., Singh, Y., Singh, P., Kundu, A.L., Sakal, R., Ram, N., Regmi,
A.P., Gami, S.K., Bhandari, A.L., Amin, R., Yadav, C.R., Bhattarai,
E.M., Das, S., Aggarwal, H.P., Gupta, R.K., Hobbs, P.R., 2003. How
extensive are yield declines in long-term rice–wheat experiments in
Asia? Field Crops Res. 81, 159–180.
Mandal, A.K., Pal, H., 1965. Study on the soil available phosphorus as
affected by cropping with jute under the influence of nitrogen from
organic and inorganic sources. Jute Bull. 57–59.
Mandal, A.K., Roy, A.B., Pal, H., 1981. Fertilizer use in jute based cropping
system in individual agro-climatic zones. Fert. News 45–50.
Mandal, B.C., Roy, A.B., Saha, M.N., Mondal, A.K., 1984. Wheat yields
and soil nutrient status as influenced by continuous cropping and
manuring in a jute–rice–wheat rotation. J. Ind. Soc. Soil Sci. 32,
696–700.
Mukhopadhyaya, S.K., Roy, D., 2000. Potato-based crop rotations in West
Bengal. Environ. Ecol. 18, 793–797.
Nambiar, K.K.M., 1994. Soil Fertility and Crop Productivity under Long
Term Fertilizer Use in India. ICAR, New Delhi, India, pp. 144.
Panaullah, G.M., Timsina, J., Saleque, M.A., Ishaque, M., Pathan,
A.B.M.B.U., Connor, D.J., Saha, P.K., Quayyum, M.A., Humphreys,
E., Meisner, C.A., 2006. Nutrient uptake and apparent balances for rice–
wheat sequences. III. Potassium. J. Plant Nutr. 29, 173–187.
Parihar, S.S., Pandey, D., Shukla, R.K., Verma, V.K., Chaure, N.K.,
Choudhary, K.K., Pandya, K.S., 1999. Energetics, yield, water use
and economics of rice based cropping system. Ind. J. Agron. 44,
205–209.
Sadanandan, N., Mhapatra, I.C., 1972. Effects of various cropping
patterns on pH of upland alluvial rice soils. Ind. J. Agron. 18,
41–44.
Sah, R.N., Mikkelsen, D.S., 1986. Transformation of inorganic phosphate
during the flooding and draining cycles of soil. Soil Sci. Soc. Am. J. 50,
62–67.
Saha, M.N., Saha, A.R., Mandal, B.C., Roy, P.K., 2000. Effect of long-term
Jute–R–W cropping system on crop yield and soil fertility. In: Abrol,
I.P., Bronson, K.F., Duxbury, J.M., Gupta, R.K. (Eds.), Long-term Soil
Fertility Experiments in R–W Cropping Systems. R–W consortium
Paper Series 6. R–W Consortium for the IGPs, New Dehli, pp. 94–
104.
Saleque, M.A., Timsina, J., Panaullah, G.M., Ishaque, M., Pathan,
A.B.M.B.U., Connor, D.J., Saha, P.K., Quayyum, M.A., Humphreys,
E., Meisner, C.A., 2006. Nutrient uptake and apparent balances for rice–
wheat sequences. II. Phosphorus. J. Plant Nutr. 29, 157–172.
Sarkar, A., 1997. Energy use patterns in sub-tropical rice-wheat cropping
under short-term application of crop residue and fertilizer. Agric.
Ecosyst. Environ. 61, 59–67.
SenGupta, P.K., 2001. Monograph on West Bengal. Directorate of Agriculture, Government of West Bengal, Kolkata, India.
Singh, G.B., Beniwal, R.K., 1983. Performance of wheat and mustard in
cropping sequences in Sikkim. Ind. J. Agric. Sci. 53, 820–825.
Smaling, E.M.A., Fresco, L.O., 1993. A decision-support model for monitoring nutrient balances under agricultural land use (NUTMON).
Geoderma 60, 235–256.
Smith, J.L., Doran, J.W., 1996. Measurement and use of pH and electrical
conductivity for soil quality analysis. In: Doran, J.W., Jones, A.J.
(Eds.), Methods for Assessing Soil Quality. SSSA Spec. Pub. No. 49.
SSSA, Madison, WI, pp. 169–185.
Subbian, P., Gopalsundaran, P., Palaniappan, S.P., 1995. Energetics and
water use efficiency of intensive cropping system. Ind. J. Agron. 40,
398–401.
Timsina, J., Connor, D.J., 2001. Productivity and management of R–W
cropping systems: issues and challenges. Field Crops Res. 69, 93–
132.
Timsina, J., Panaullah, G.M., Saleque, M.A., Ishaque, M., Pathan,
A.B.M.B.U., Quayyum, M.A., Connor, D.J., Shah, P.K., Humphreys,
E., Meisner, C.A., 2006. Nutrient uptake and apparent balances for rice–
wheat sequences. I. Nitrogen. J. Plant Nutr. 29, 137–156.
Timsina, J., Singh, U., Badaruddin, M., Meisner, C., Amin, M.R., 2001.
Cultivar, nitrogen, and water effects on productivity, and nitrogen-use
efficiency and balance for rice–wheat sequences of Bangladesh. Field
Crops Res. 72, 143–161.
Tomar, S.S., Tiwari, A.S., 1990. Production potential and economics of
individual crop sequences. Ind. J. Agron. 35, 30–35.
B. Biswas et al. / Field Crops Research 99 (2006) 35–47
van Gestel, M., Merckx, R., Vlassak, K., 1993. Microbial biomass responses
to soil drying and rewetting: the fate of fast and slow growing microorganisms in the soils from individual.
Willett, I.R., Higgens, M.L., 1978. Phosphate sorption by reduced and
deoxidized rice soils. Aust. J. Soil. Res. 16, 319–326.
Witt, C., Cassman, K.G., Olk, D.C., Biker, U., Liboon, S.P., Samson, M.I.,
Ottow, J.C.G., 2000. Crop rotation and residue management effects on
carbon sequestration, nitrogen cycling and productivity of irrigated rice
systems. Plant Soil 225, 263–278.
47
Yadav, R.L., Dwivedi, B.S., Pandey, P.S., 2000. Rice–wheat cropping
systems: assessment of sustainability under green manuring and chemical fertilisers input. Field Crop. Res. 65, 15–30.
Yadvinder-Singh, Bijay-Singh, Timsina, J., 2005. Crop residue management for nutrient cycling and improving soil productivity in rice-based
cropping systems in the tropics. Adv. Agron. 85, 269–407.
Yadvinder-Singh, Dobermann, A., Bijay-Singh, Bronson, K.F., Khind, C.S.,
2000. Optimal phosphorus management strategies for wheat-rice cropping on a loamy sand. Soil Sci. Soc. Am. J. 64, 1413–1422.