Directory UMM :Data Elmu:jurnal:S:Soil & Tillage Research:Vol56.Issue1-2.Jul2000:

Soil & Tillage Research 56 (2000) 67±82

Crop establishment of legumes in rainfed lowland
rice-based cropping systems
A.A. Rahmiannaa,1, T. Adisarwantob, G. Kirchhof a,2, H.B. Soa,*
a

School of Land and Food Sciences, The University of Queensland, St. Lucia, Brisbane, Qld 4072, Australia
b
Research Institute for Food Legumes and Tuber Crops, Kendalpayak, Malang 65101, Indonesia

Abstract
Poor crop establishment is one of the major limitations to the production of grain legumes after rice (Oryza sativa L.) in
rainfed lowland rice-based cropping systems. The success of germination and emergence of mungbean (Vigna radiata (L.)
Wilzek), soybean (Glycine max (L.) Merr) and peanut (Arachis hypogaea L.) planted in zero tilled (ZT), zero tilled combined
with mulch application (ZTM) and tilled soils (T) were investigated in a crop establishment trial as a function of sowing delay.
Sowing delay was used as a surrogate for soil-water content. This experiment was conducted under a rain-shelter to ensure
continuous and progressive drying conditions. A dibbling trial using the same legumes was conducted concurrently and
subjected to the prevailing climatic conditions. Germination and emergence success rate of the traditional dibbling method
was compared to dibbling incorporating depth control and seed cover. Both experiments were conducted towards the end of
the 1994 rainy season in a Vertisol soil at Ngale and an Andosol soil at Jambegede, in East Java, Indonesia where the season

gradually changes from wet to dry season. Mungbean emergence was 93±94% at Ngale and soybean emergence was 84±95%
at Jambegede, both in the presence and absence of rain. Peanut emergence was low (50±69%) at both sites. In all three species
at both sites, the percentage of seeds that failed to germinate was greater than seeds that failed to emerge, indicating that
germination rather than emergence was limiting. Seed rot caused by fungal attack and poor imbibition associated with poor
seed±soil contact (observed as intact seeds) were the main constraints for the success of germination of mungbean, soybean
and peanut. The failure to emerge was mainly caused by seedling rot and the failure of hypocotyl and radicle to penetrate the
hard soil, observed as a curling of the hypocotyl. Cultivation at Ngale on a Vertisol resulted in excessively cloddy soil, which
in turn resulted in a signi®cant decrease in germination and emergence. The application of straw mulch had little effect on the
emergence of legumes on this soil. The use of depth control and application of seed±soil cover did not have a signi®cant effect.
Hence the traditional dibbling method where depth of planting ranged from 4 to 7 cm without seed cover was found to be
appropriate for planting mungbean and soybean. Germination and emergence of peanut was improved with the application of
soil cover and the dibbling stick had a spike added to the tip to assist the root to penetrate the hard compacted soil.
# 2000 Elsevier Science B.V. All rights reserved.
Keywords: Germination; Crop establishment; Grain legumes; Rainfed lowland rice; Soil water potential; Dibbling

*
Corresponding author. Tel.: ‡61-7-3365-2888; fax: ‡61-7-3365-1188.
E-mail address: h.so@mailbox.uq.edu.au (H.B. So).
1
Present address: Research Institute for Food Legumes and Tuber Crops, Kendalpayak, Malang 65101, Indonesia.

2
Present address: NSW Agriculture, PMB 944, Tamworth, NSW 2340, Australia.

0167-1987/00/$ ± see front matter # 2000 Elsevier Science B.V. All rights reserved.
PII: S 0 1 6 7 - 1 9 8 7 ( 0 0 ) 0 0 1 2 3 - 9

68

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

1. Introduction
Poor crop establishment is generally accepted as
one of the major limitations to the production of grain
legumes after rice within a rainfed lowland rice-based
cropping system (Greenland, 1985; Carangal, 1986;
Fy®eld and Gregory, 1989; Fy®eld et al., 1990).
Inferior seed quality, inadequate land preparation,
fungal and pest attacks, excessive soil moisture, poor
soil drainage, inappropriate method of planting and
the massive structure of puddled soils have been listed

as factors contributing to poor establishment (Hundal
and Tomar, 1985; Sumarno and Adisarwanto, 1992;
Cook et al., 1995; Garrity and Liboon, 1995).
Sowing after rice harvest is considered inappropriate when there is excessive wetness of the soil leading
to possible waterlogging of the seed, particularly
where the probability of rain is high during the latter
part of the rainy season (Hundal and Tomar, 1985).
Although generally accepted, this opinion has not
been supported by scienti®c observations. On the
other hand, delayed sowing of legumes after rice
may encounter dry soils that are compact and hard
(Cook et al., 1995; Kirchhof and So, 1995; So and
Ringrose-Voase, 2000). Between these two conditions
is an ideal window of opportunity, which should result
in good crop establishment. The limits of this window
of opportunity need to be clearly de®ned.
A practice frequently adopted by farmers is to
cultivate the soil to reduce the effect of saturation
and to break up the puddled soil. However, cultivation
of this wet soil, in particular clay soils, may lead to

other problems. The ®rst is excessive cloddiness if
cultivation is carried out when the water content is too
high, which result in excessive drying and poor seed±
soil contact. Increasing turn around time (TAP)
between rice harvest and sowing can increase the
probability of seedling establishment failure and the
likelihood of drought stress during the later growth
stages of the legume crop.
An important factor affecting the success rate of
crop establishment is the planting technique adopted
by the farmer. The two most widely adopted techniques in Asian countries are broadcasting and dibbling
the seeds either in rows or randomly and the planting
technique adopted appears to be location speci®c
(Syarifuddin, 1982; Sumarno et al., 1988; Benjasil
et al., 1992; Chainuvati, 1992; Gypmantasiri, 1992;

Irawan and Lancon, 1992; Sarobol et al., 1992;
Sumarno and Adisarwanto, 1992; Virakul, 1992; Sanidad, 1996).
Seed broadcasting is associated with poor spatial
distribution, poor seed and soil contact and excessive

seed loss due to scavenging by birds and ants (Cardwell, 1984; Pratley and Corbin, 1994). Dibbling, on
the other hand, is time consuming, labour intensive
and requires extra expenses for ash/compost/straw to
ensure adequate seed cover (Benjasil et al., 1992;
Gypmantasiri, 1992) and a delay in sowing may result
in increasing soil strength due to soil drying (Garrity
and Liboon, 1995).
Potentially, dibbling should result in better establishment than the broadcast method, as seeds are less
exposed and spatial distribution of plants is superior,
but the variable success of dibbling by the farmer has
been associated with a lack of consistency in the
method adopted. An improved dibbling method
should therefore increase establishment and crop
yield.
Considerable research has been conducted in Indonesia to increase dry season grain legume yields
(Sumarno, 1991). Most of the work has focused on
irrigated crops, with less attention given to crops
grown under rainfed conditions after rice.
The objectives of this work is to investigate (1) the
effects of cultivation and sowing delay (as a surrogate

for soil water status) on the establishment of mungbean, peanut and soybean in puddled soils after rice,
and (2) the factors affecting the success rate of establishment from seeds sown with the traditional dibbling
technique.

2. Materials and methods
The study consisted of two experiments: (1) crop
establishment under continuous drying conditions and
(2) dibbling trial. Both experiments were conducted
on a Vertisol at Ngale and an Andosol at Jambegede.
Details of these soils and climates are described by
Schafer and Kirchhof (2000).
2.1. Crop establishment trial
To prevent interference from rain and to ensure
continuous and progressive drying conditions, a

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

15 m6 m PVC rain-shelter was set up over a selected
part of the rice ®elds at Ngale and Jambegede. These
®elds were adjacent to the E2 experiments of ACIAR

Project 8938 (So and Ringrose-Voase, 2000) and were
drained 1 week before harvest. The rain-shelter was
set up immediately prior to harvest, so that soil-water
contents at harvest were as close as possible to those
expected outside the rain-shelter. Rice harvest
occurred on 20 March 1994 at Ngale and on 23 April
1994 at Jambegede.
A split±split plot experiment was set up under the
rain-shelter with treatments consisting of three cultivationsthree periods of sowing delaythree legume
speciesthree replicates resulting in a total of 81
plots. Delay of sowing was the main plot treatment
with cultivation as subplot and species as sub-subplot.
Delay in sowing represented different soil water conditions at sowing and were D0 (immediately after rice
harvest), D1 (1 week delay) and D2 (2 weeks delay).
These were 3, 10 and 17 days after rice harvest at
Ngale and 4, 11 and 18 days at Jambegede. Cultivation
treatments consisted of zero tillage (ZT), zero tillage
with mulch (5 Mg haÿ1 dry rice straw) (ZTM) and
cultivation by a hand operated hoe to 12.5 cm depth
(T). The three legume species used were mungbean cv.

Walet, peanut cv. Kelinci and soybean cv. Wilis (all
are Indonesian released cultivars).
Each subplot was 1.5 m1.5 m and seeds were
planted with a spatial arrangement of 15 cm15 cm
with two seeds per hole. Planting was conducted using
a sharpened dibbling stick, which created a hole 5 cm
deep and 4 cm wide in diameter at the top. Seeds were
placed in the hole and covered by moist soil to the
surface. Drainage ditches were provided around the
perimeter of the area to avoid run-off water. Side
covers of the shelter were left open, but closed during
rainfall events to prevent rain from entering the shelter.
The number of seedlings emerged was recorded
daily starting at 4 days after sowing (DAS) until 14
DAS. Cumulative germination was recorded daily. At
14 days, the difference between the number of seeds
sown and the seedlings that emerged was determined.
Seeds that failed to germinate (no radicle growth from
the seed or seed is rotting) or the seedlings that failed
to emerge (germinated seeds but not emerged) were

recovered, counted and the cause of failure examined
and recorded.

69

Measurement of soil physical properties was limited to soil temperature and gravimetric soil-water
content. Temperature at the soil surface at 2.5, 5
and 10 cm soil depths were measured using thermocouples buried at two sites in the ®eld and at corresponding depths. During the ®rst 48 h, readings were
made every hour to obtain the temperature diurnal
cycle as well as the time when the maximum temperature occurred for each depth. On the following
days, daily recordings were made at these times. Soilwater content was estimated by digging two 20 cm
holes using a spade such that one face is nearly
perpendicular. A slice of 1±2 cm thickness was taken
from this face and water content determined gravimetrically at 1 cm increments for the ®rst 10 cm, and
every 2.5 cm increment between 10 and 20 cm
depth. At each sampling time the same soil face
was cleared by removing a slice of approximately
3±4 cm before a fresh slice is taken and measurements
repeated. Soil water potentials were derived using
the soil water characteristic curves of undisturbed

cores collected from the ®eld and determined in the
laboratory using a series of pressure plates. Observation was made at each planting time and on every
second day thereafter.
Seed viability (potential for germination) was determined in the laboratory using the standard germination test (International Seed Testing Association,
1985).

2.2. Dibbling trial
Due to rainfall at Ngale, planting was made 11 days
after rice harvest (3 April 1994) when the soil was
judged as ready for dibbling, while at Jambegede, it
was started sooner at 7 days after rice harvest (1 May
1994).
A split plot design was used to set up the experiment. The treatments consisted of six types of dibbling
techniquethree species®ve replicates resulting in a
total of 90 plots. The six dibbling methods were made
up of a combination of depth control, soil cover (in this
experiment sand was used in place of soil) and the
shape of dibbling hole. These were
1. normal dibbling, with no depth control and no soil
cover (farmers practice);

70

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

2. normal dibbling, with no depth control, with soil
cover;
3. normal dibbling, with depth control, with no soil
cover;
4. normal dibbling, with depth control and soil
cover;
5. similar to (4) plus spike (to assist roots to
penetrate the soil); and
6. narrow slit, with depth control and soil cover; the
narrow hole was expected to reduce evaporation
and seed drying.
Following farmer's practice, normal dibbling was
conducted using a sharpened dibbling stick, similar
to that used for the crop establishment trial. A planting
depth of 5 cm was used for the depth control treatments. In the non-depth control treatment, which
represented the farmer's practice, seed placement
depths varies from 4 to 7 cm and were mostly greater
than 5 cm deep. Moist sand was used as seed cover in
treatments 2, 4 and 6. The spike for treatment 5 was
made with a wire 2 mm in diameter, and was applied at
the centre of the seed hole prior to seed placement.
The narrow slit (treatment 6) was produced by a small
stick with a width of 1 cm at the top and the seed was
planted at 5 cm depth.
The same batch of three legumes species: mungbean cv. Walet, peanut cv. Kelinci and soybean cv.
Wilis were used in these experiments. Each plot
was 3 m2 m and seeds were planted with a
spatial arrangement of 15 cm15 cm with two seeds
per hole except for the narrow slit with one seed per
hole.
Soil temperature was measured at 0, 2.5, 5 and
10 cm depths using thermocouples. Recording of
temperature was made daily at the same time when
the maximum temperature occurred for each depth,
which was obtained from an hourly recording during
the ®rst 48 h. Soil-water content was measured in 1 cm
increments for the ®rst 10 cm, and every 2.5 cm from
10 to 20 cm using the gravimetric method. Similar
times of sampling were used as for the crop establishment trial.
Observation of emergence was recorded daily starting at 4 DAS until 14 DAS. At 14 days, seeds that
failed to germinate or seedlings that failed to emerge
were recovered, counted and the causes of failure
examined and recorded.

3. Results and discussion
3.1. Crop establishment under drying conditions
Tables 1 and 2 show the data on emergence (the
appearance of seedlings at the soil surface), germination (radicle has pierced the seed coat) and emergence
failures for Jambegede and Ngale. The latter refers to
germinated seeds that failed to emerge (i.e. germination minus emergence). In almost all cases, the failure
of seeds to germinate was greater than the failure to
emerge. Table 3 shows the range of soil water potentials at 0, 4 and 14 DAS for the two sites, which were
derived from soil-water contents. In general, the heavy
clay soil at Ngale had the lowest soil water potentials
than the lighter soils of Jambegede although visually
the Ngale soil may appear wetter.
A comparison of the three legume species shows
that the emergence of mungbean was very high at
Ngale (92.94.3%), followed by soybean (80.9
14.8%) and peanuts (64.123%). In the wetter soils
at Jambegede, soybean performed best (94.84.9%)
followed by mungbean (70.710.7%) and peanuts
(69.912.5%). These are percentages of viable seeds,
which were tested in the laboratory using sandboxes
and the results indicated that the potential germination
of mungbean was 96%, soybean 81.7% and peanuts
88.7%.
So (1987) pointed out that for germination to be
successful, seeds would have to take up water at a
suf®ciently rapid rate and reach a critical water content necessary for germination processes to be
initiated before other factors (such as fungal or bacteria infection and soil drying) prevented it from
completing the process. On the basis of seed size,
critical water contents and the associated rates of
germination (Dart et al., 1992), it was expected that
establishment would be best and most rapid in mungbean followed by soybean and peanuts, which was
con®rmed at Ngale (Table 1). However, the sequence
between mungbean and soybean was reversed in the
wetter soil of Jambegede (Table 2) as a result of a high
incidence of seed rot in mungbean. The average failure
to germinate at Jambegede was 19.4% compared to an
average of 5.5% at Ngale. At Jambegede, mungbean is
a common crop and a compatible inoculum is likely to
be present in suf®ciently large numbers in that soil to
infect the seeds. The incidence of germination failure

Table 1
Emergence, failure of germination and failure of emergence (%) for mungbean, peanut and soybean at three delays of planting and three types of cultivation planted at Ngalea
Treatments

Mungbean

Peanut

Soybean

Cultivation % Emergence % Germination % Emergence % Emergence % Germination % Emergence % Emergence % Germination % Emergence
failure
failure
failure
failure
failure
failure

D0

ZT
ZTM
T

96.1 (1.6)
98.9 (1.6)
91.1 (5.6)
95.4

2.8

1.8

70.7

13.3

15.9

93.7

1.7

4.6

ZT
ZTM
T

93.9 (2.1)
94.5 (2.1)
90.6 (6.3)

6.1 (2.1)
5.6 (2.1)
8.9 (6.7)

0 (0)
0 (0)
0.6 (0.8)

90.0 (4.9)
87.8 (6.3)
62.2 (9.1)

4.4 (2.1)
5.4 (4.5)
27.2 (1.6)

5.6 (4.2)
6.9 (3.5)
10.6 (7.5)

87.2 (4.4)
80.0 (17.0)
71.7 (14.3)

8.3 (2.4)
8.9 (6.2)
20.0 (12)

4.5 (2.1)
11.1 (11)
8.4 (3.6)

93.0

6.9

0.2

80.0

12.3

7.7

79.6

12.4

8.0

94.4 (0.8)
93.4 (2.4)
82.8 (4.4)

5.0 (1.4)
3.3 (1.4)
12.8 (3.9)

0.6 (0.8)
3.3 (2.7)
4.4 (0.8)

54.5 (10.4)
61.1 (11.3)
9.4 (5.5)

30.0 (5.9)
25.6 (11.6)
73.9 (3.9)

15.5 (5.7)
13.3 (3.6)
16.7 (2.4)

82.8 (8.2)
81.7 (2.7)
44.4 (12.3)

6.1 (5.1)
9.4 (4.4)
40.6 (11)

11.1 (8.6)
8.9 (2.8)
15.0 (2.7)

Average (D2)

90.2

7.0

2.8

41.7

43.2

15.2

69.6

18.7

11.7

Mean ZT
Mean ZTM
Mean T

94.8
95.6
88.2

4.6
2.9
9.0

0.6
1.5
2.7

75.8
73.3
43.3

12.5
14.0
42.2

11.7
12.7
14.5

88.1
85.9
68.9

4.8
6.7
21.3

7.1
7.4
9.8

Overall mean
(species)

92.9 (4.3)

5.5 (3.5)

1.6 (1.5)

64.1 (23.0)

22.9 (20.7)

12.9 (4.1)

80.9 (14.8)

10.9 (11.8)

8.1 (3.7)

Average (D0)
D1

Average (D1)
D2

ZT
ZTM
T

2.8 (1.6)
0 (0)
5.5 (3.4)

1.1 (1.6)
1.1 (1.6)
3.3 (2.4)

82.8 (4.1)
71.1 (8.7)
58.3 (13.8)

3.3 (0)
11.1 (5.1)
25.6 (13)

13.9 (4.2)
17.8 (8.2)
16.1 (0.8)

94.4 (1.6)
96.1 (0.8)
90.6 (4.8)

0 (0)
1.7 (2.4)
3.3 (1.4)

5.6 (1.6)
2.2 (1.6)
6.1 (4.4)

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

Delay

a

Delay Ð D0: immediately; D1: 1 week; D2: 2 weeks after rice harvest; cultivation Ð ZT: zero till; ZTM: zero till mulched; T: tilled with hand hoe. LSD 5%: species: 4.81,
delay of planting: 9.99; type of cultivation: 4.05. Values in brackets are standard errors.

71

72
Table 2
Emergence, failure of germination and failure of emergence (%) for mungbean, peanut and soybean at three delays of planting and three types of cultivation planted at Jambegedea
Treatments

Mungbean

Peanut

Soybean

Cultivation % Emergence % Germination % Emergence % Emergence % Germination % Emergence % Emergence % Germination % Emergence
failure
failure
failure
failure
failure
failure

D0

ZT
ZTM
T

Average (D0)
ZT
ZTM
T

D1

Average (D1)
D2

ZT
ZTM
T

78.9 (9.6)
83.3 (4.7)
76.7 (7.2)

16.6 (9.8)
11.1 (6.9)
16.6 (2.7)

4.4 (3.1)
5.6 (4.2)
6.6 (7.2)

82.2 (5.7)
82.2 (4.2)
72.3 (12.8)

7.8 (4.1)
11.1 (3.1)
15.5 (6.3)

10 (2.7)
6.7 (4.7)
12.2 (6.9)

94.4 (1.6)
96.7 (2.7)
91.1 (6.9)

3.3 (2.7)
3.3 (2.7)
4.4 (4.2)

2.2 (3.1)
0 (0)
4.4 (3.1)

79.6

14.8

5.5

78.9

11.5

9.6

94.1

3.7

2.2

64.5 (4.2)
66.3 (2.3)
80.0 (9.4)

25.5 (1.6)
32.2 (1.6)
14.4 (6.8)

10.0 (5.4)
1.1 (1.6)
5.6 (4.2)

61.2 (18.5)
65.6 (12.5)
66.7 (7.2)

25.5 (13.7)
26.6 (11.8)
22.2 (6.9)

13.3 (8.2)
7.8 (1.6)
11.1 (4.1)

96.7 (4.7)
94.4 (4.2)
91.1 (3.1)

2.2 (3.1)
1.1 (1.6)
5.6 (3.1)

1.1 (1.6)
4.4 (4.2)
3.3 (0)

70.3

24.0

5.6

64.5

24.8

10.7

94.1

3.0

2.9

b

62.2 (5.7)
67.8 (1.6)
56.7 (5.4)

na
na
na

na
na
na

60.0 (7.2)
72.2 (4.2)
66.7 (7.2)

na
na
na

na
na
na

97.8 (1.6)
98.9 (1.6)
92.2 (6.3)

na
na
na

na
na
na

Average (D2)

62.2

na

na

66.3

na

na

96.3

na

na

Mean ZT
Mean ZTM
Mean T

68.5
72.5
71.4

21.1
21.7
15.5

7.2
3.4
6.1

67.8
73.3
68.6

16.6
18.9
18.9

11.7
7.3
11.7

96.3
96.7
91.5

2.81
2.2
5.0

1.7
2.2
3.9

Overall mean
(species)

70.7 (10.7)

19.4c (9.2)

5.5c (2.7)

69.9 (12.5)

18.1c (11.2)

10.2c (2.3)

94.8 (4.9)

3.3c (3.3)

2.6c (1.6)

a

Delay Ð D0: immediately; D1: 1 week; D2: 2 weeks after rice harvest; cultivation Ð ZT: zero till; ZTM: zero till mulched; T: tilled with hand hoe. LSD 5%: species: 5.01;
delay of planting: 7.49; type of cultivation: 4.35. Values in brackets are standard errors.
b
Not available.
c
Averaged from two treatments (D0 and D1).

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

Delay

73

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

Table 3
The range of soil water potentials (MPa) at 5 cm depth in the various combination of sowing delay and type of cultivation at Jambegede and
Ngale for the period of 0±4 days and 14 days after sowing (DAS)
Treatments
Sowing delay

Water potential (MPa) after sowing
Type of cultivation

Jambegede
0 DAS

Ngale
4 DAS

14 DAS

1 DAS

4 DAS

14 DAS

ÿ0.004
0
ÿ0.016

ÿ0.025
ÿ0.036
ÿ0.56

ÿ0.018
ÿ0.05
ÿ0.036

ÿ0.022
ÿ0.045
ÿ0.028

ÿ0.056
ÿ0.079
ÿ0.112

D0

ZT
ZTM
T

D1

ZT
ZTM
T

ÿ0.02
ÿ0.016
ÿ0.11

ÿ0.035
ÿ0.014
ÿ0.18

ÿ0.036
ÿ0.036
ÿ0.71

ÿ0.045
ÿ0.045
ÿ0.071

ÿ0.04
ÿ0.063
ÿ0.159

ÿ0.071
ÿ0.20
ÿ0.20

D2

ZT
ZTM
T

ÿ0.025
ÿ0.036
ÿ0.56

ÿ0.045
ÿ0.04
ÿ0.79

ÿ0.14
ÿ0.089
ÿ6.31

ÿ0.056
ÿ0.079
ÿ0.112

ÿ0.063
ÿ0.079
ÿ0.282

ÿ0.28
ÿ0.28
ÿ1.12

0
0
0

due to seed rot was 10.9% for soybean at Ngale
compared to 3.3% at Jambegede, most probably associated with the cropping history of the region and the
presence of compatible inoculum. Soybean is the
common legume crop after rice at Ngale.
Cultivation of the Vertisol 1 week after rice harvest
resulted in a very cloody seedbed which contributed to
the failure of germination as a result of poor seed±soil
contact and reduced imbibition. This is observed as
intact seeds. The high incidence of germination failure
in peanuts was not associated with fungal infection,
but rather with poor seed±soil contact as a signi®cant
proportion of seeds remained intact (18.1% at Jambegede and 22.9% at Ngale). In addition, a signi®cant
proportion of germinated peanut seeds failed to
emerge (10±13%), probably as a consequence of
the high soil strength at the time of emergence. Even
though germination of the three legumes was rapid,
peanut emergence was considerably slower than the
other legumes (the emergence for mungbean and
soybean started at 3±4 DAS compared to 6±7 DAS
for peanut).
In the absence of rain, an increasing period of delay
in sowing legumes after rice harvest generally reduced
the emergence and establishment of legumes at both
Jambegede and Ngale except for mungbean at Ngale
and soybean at Jambegede. Increasing the period of
sowing delay lead to low water potentials (Table 3).
Therefore, the rate of water uptake by the seed and
hence rate of germination was reduced and the oppor-

tunity for fungal infection was increased. This is
consistent with the ®nding of Bewley and Black
(1985), who reported that germination is not affected
by soil water potential until it reaches fairly low values
provided biotic factors are controlled. Therefore, if
fungal infection is not likely to occur, 1 or 2 weeks
sowing delay should not affect germination signi®cantly, which is the case with mungbean at Ngale and
soybean at Jambegede. Thus, it appeared that under
the condition of this experiment, the reduction in
establishment with a delay in sowing was strongly
associated with increased opportunity for fungal infection due to the reduced rate of germination. Therefore
in such cases, the use of appropriate fungicides for
seed treatment may alleviate some or all of the problems.
It should be noted that this experiment was carried
out in East Java where the transition from the rainy
season to the dry season is gradual and drying conditions during the experiment was relatively mild.
Hence soil strength did not appear to be limiting.
The effect of increasing sowing delay on seed germination and emergence will most likely be greater if the
rate of soil drying is increased and soil strength
becomes an important limiting factor, e.g. in drier
areas with an abrupt end to the rainy season.
The effect of cultivation and mulch on legume
establishment were not consistent between the two
sites. Cultivation of the top 12.5 cm (treatment T)
resulted in greater rate of soil drying (Fig. 1) and

74

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

Fig. 1. Soil-water content (g/g) at various times after harvest in the top of 12 cm soil depth in zero tillage (&), zero tillage and mulch (5) and
tilled (*) in the Andosol soils at Jambegede and Vertisol soils at Ngale. The solid lines indicate the value of LSD with 95% level of
con®dence.

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

signi®cantly lower soil potentials (Table 3). This effect
was greater in the lighter textured Andosol at Jambegede (Table 3). This soil with a plant available water
capacity (PAWC) of 0.14 m3/m3, was higher in water
potentials than the Vertisol at Ngale immediately after
rice harvest, but after 17 days its water potential was
less than the Vertisol, which can hold a greater amount
of water (PAWC of 0.32 m3/m3).
The use of 5 Mg haÿ1 of rice straw as soil mulch
was intended to reduce water loss from surface evaporation, however, the data show that the effect on
soil-water content in the seed placement zone was
insigni®cant (Fig. 1 and Table 3) and very little effect
on seedling emergence.
Cultivation tended to produce a cloddy surface soil
that increased the rate of soil drying, and result in
reduced germination and emergence, particularly on
the Vertisol at Ngale. The high rate of failure to
germinate in this soil under the tillage (T) treatment
(Table 1) is largely attributed to poor seed±soil contact. The cloddy nature may also allow deeper penetration of light and the premature breaking of the
hypocotyl before emergence is completed. Cultivation
had very little effect on the germination or emergence
of any of the legumes in the Andosol at Jambegede
despite the drier conditions (Table 3), probably
because this soil displayed a ®ner surface tilth and
hence better seed±soil contact.
3.2. Crop establishment in the dibbling trial
Data on emergence, germination and emergence
failure for mungbean, soybean and peanut planted
at Ngale and Jambegede are presented in Tables 4
and 5. The percentage of peanut and soybean seeds
that emerged was clearly smaller than the percentage
of seeds that germinated. Hence it appeared that the
main limitation to establishment of peanut and soybean was the strength of the dry surface soil or sand.
The number of mungbean seedlings that failed to
emerge was low, whereas the number that failed to
germinate was high for all dibbling types at Jambegede. Table 6 shows the range of soil water potentials
at 0, 4 and 14 days after sowing for the two sites. The
soil water potentials in the Andosol at sowing were
slightly higher compared to the Vertisol at Ngale,
although there was more rain at Ngale (76 mm) than
Jambegede (49 mm) during the ®rst 14 days. Soil-

75

water contents did not appear to be limiting seedling
establishment.
In the dibbling trial, the relative performance of the
three species in the presence of rainfall (dibbling trial)
was similar to that in the absence of rainfall (rainshelter). Mungbean performed best (943.8%), followed by peanut (69.113.4%) and soybean
(52.518.2%) at Ngale. At higher water potentials
at Jambegede, soybean performed best (84.215.2%),
followed by mungbean (72.47.9%) and peanut
(50.513.3%). Compared to the emergence at Ngale,
mungbean emergence at Jambegede was lower by
21.6%. For soybean, however, there was a signi®cant
increase (32%). It showed that germination and emergence of mungbean are susceptible to wet conditions
while soybean was better able to cope with wet
conditions.
Low emergence of mungbean at Jambegede was
associated with high germination failure caused by a
high incidence of seed rot (average 20.3%). The
combination of wet soil and warm conditions (soil
temperature at 5 cm depth averaged 318C at Jambegede and 338C at Ngale) promoted fungal growth. The
low emergence of soybean at Ngale was mainly
caused by the high number of seedlings (average
35.2%) unable to emerge (curling growth). This
was caused by the failure of radicle to penetrate the
hard soil.
Peanut performed better at Ngale than Jambegede.
There was higher germination failure on the wetter soil
at Jambegede. Seed rot and incomplete imbibition
were observed as the main causes for this failure.
At both sites, low emergence was caused by the failure
of the hypocotyl to emerge through the soil surface,
with an average of 27.6% at Ngale and 34.5% at
Jambegede.
Treatment responses of mungbean were similar at
both locations, except for peanut and soybean. The
depth of planting, seed cover and the size of the
dibbling hole did not affect mungbean emergence.
Small seeds completed germination rapidly and emergence is high, even with very wet soils around the
seeds. The emergence of peanut and soybean varied
for each dibbling technique at both sites. Depth control and soil cover did not in¯uence soybean emergence. However, emergence of soybean planted at
5 cm soil depth using a slit (T6) severely reduced
its emergence both at Jambegede and Ngale. The main

76

Dibbling
technique

Mungbean
% Emergence

% Germination
failure

% Emergence
failure

% Emergence

% Germination
failure

% Emergence
failure

% Emergence

% Germination
failure

% Emergence
failure

T1
T2
T3
T4
T5
T6

95.4
95.4
95.2
93.4
96.6
88.2

1.1
4.6
4.8
6.6
3.4
3.0

(0.4)
(1.3)
(1.7)
(4.0)
(1.0)
(2.6)

3.5 (2.1)
0 (0)
0 (0)
0 (0)
0 (0)
8.8 (1.9)

55.4
77.8
52.2
78.2
74.4
76.6

5.2
1.2
5.9
0.5
0.7
6.5

39.4
21.0
41.9
21.3
24.9
16.9

65.0
62.6
56.8
58.6
52.2
19.8

(4.6)
(9.0)
(15.8)
(12.4)
(5.0)
(6.9)

6.7 (0.8)
8.2 (4.0)
7.3 (1.6)
13.0 (1.1)
12.4 (4.6)
26.3 (8.6)

28.3
29.2
35.9
28.4
35.4
53.9

3.9 (2.6)

2.0 (3.5)

69.1 (13.4)

52.5 (18.2)

12.3 (7.9)

35.2 (13.0)

Average
a

(2.1)
(1.4)
(4.6)
(4.6)
(1.0)
(3.1)

94.0 (3.8)

Peanut

(13.8)
(5.0)
(6.5)
(2.4)
(5.1)
(8.6)

Soybean

(4.7)
(1.9)
(2.0)
(0.4)
(0.7)
(5.9)

3.3 (4.0)

(7.5)
(4.7)
(2.1)
(3.2)
(1.7)
(7.4)

27.6 (10.7)

(5.4)
(4.0)
(16.2)
(14.9)
(4.8)
(8.1)

Dibbling technique Ð T1: farmers practise; T2: soil cover; T3: depth control; T4: soil cover and depth control; T5: as T4 plus spike; T6: narrow slit. LSD 5%: species: 6.69;
dibbling technique: 11.29. Values in brackets are standard errors.

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

Table 4
Emergence, failure of germination and failure of emergence (%) for mungbean, peanut and soybean in the six dibbling techniques planted at Ngalea

Dibbling
technique

Mungbean
% Emergence

% Germination
failure

% Emergence
failure

% Emergence

% Germination
failure

% Emergence
failure

% Emergence

% Germination
failure

% Emergence
failure

T1
T2
T3
T4
T5
T6

71.2
72.8
69.2
74.8
75.2
71.0

22.4
20.4
25.7
18.0
16.9
18.2

6.4
6.8
5.1
7.2
7.9
10.8

44.2
46.6
41.2
45.8
60.8
64.6

19.7
10.0
28.7
8.5
14.9
10.5

35.4
43.4
34.1
43.1
24.3
26.9

92.6
95.8
84.6
91.2
87.8
53.2

3.3
1.1
5.7
4.4
2.4
5.7

4.1 (2.8)
3.1 (1.8)
9.7 (5.6)
4.4 (1.6)
9.8 (3.4)
41.1 (9.3)

Average
a

(8.5)
(7.9)
(12.4)
(5.2)
(4.5)
(3.6)

72.4 (7.9)

Peanut

(5.6)
(5.4)
(10.8)
(4.2)
(4.4)
(3.7)

20.3 (6.4)

(2.8)
(3.6)
(1.0)
(3.8)
(2.1)
(2.8)

7.3 (3.1)

(7.3)
(9.7)
(14.5)
(9.5)
(7.5)
(9.5)

50.5 (13.3)

Soybean

(8.0)
(2.8)
(9.2)
(3.2)
(5.9)
(3.4)

15.4 (9.0)

(9.1)
(13.2)
(16.1)
(9.9)
(3.1)
(12.9)

34.5 (12.8)

(3.8)
(2.7)
(5.4)
(3.3)
(4.3)
(8.5)

84.2 (15.2)

(2.6)
(1.1)
(2.6)
(2.1)
(1.8)
(3.4)

3.8 (2.8)

12.0 (14.2)

Dibbling technique Ð T1: farmers practise; T2: soil cover; T3: depth control; T4: soil cover and depth control; T5: as T4 plus spike; T6: narrow slit. LSD 5%: species: 7.65;
dibbling technique: 10.22. Values in brackets are standard errors.

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

Table 5
Emergence, failure of germination and failure of emergence (%) for mungbean, peanut and soybean in the six dibbling techniques planted at Jambegedea

77

78

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

Table 6
The range of soil water potentials (MPa) at 5 cm depth in the various dibbling types at Jambegede and Ngale for the period of 0±4 days and 14
days after sowing (DAS)
Treatments

Water potential (MPa) after sowing
Jambegede

Ngale

0 DAS

4 DAS

14 DAS

0 DAS

4 DAS

14 DAS

T1
T2
T3
T4
T5
T6

ÿ0.011
ÿ0.001
ÿ0.005
ÿ0.011
0
0

ÿ0.025
ÿ0.019
ÿ0.016
ÿ0.028
ÿ0.013
ÿ0.019

ÿ0.028
ÿ0.035
ÿ0.025
ÿ0.025
ÿ0.011
ÿ0.026

ÿ0.04
ÿ0.036
ÿ0.026
ÿ0.036
ÿ0.036
ÿ0.028

ÿ0.036
ÿ0.04
ÿ0.036
ÿ0.036
ÿ0.028
ÿ0.036

ÿ0.056
ÿ0.056
ÿ0.056
ÿ0.063
ÿ0.045
ÿ0.056

Amount of rainfall during the first 14 days (mm)

49

causes of the low soybean emergence at Ngale were
high germination failure caused by seed rot (26.3%),
and high emergence failure at both sides caused by
seedling rot and the failure of the seedlings to emerge
through the soil above the seed (Tables 4 and 5).
The response of peanut emergence to dibbling
techniques was different from soybean (Tables 4
and 5). Soil cover signi®cantly increased the emergence (24.2% on average) at Ngale. High evaporation
from the large exposed surface of the seed reduced the
rate of imbibition resulting in failure of seeds to
germinate. At Jambegede, the size of the seed hole
played an important role in governing the success of
emergence. Narrow seed holes (T6) signi®cantly
increased emergence (approximately 20%) compared
with normal/larger holes, probably associated with
better soil±seed contact.

76

ment was conducted with a delay time similar to D1 in
the ®rst experiment.
The result in Tables 1, 2, 4 and 5 showed germination and emergence of the three legumes were consistent across the two trials. Rain did not affect the
results in these experiments. For all three legumes and
on both soils, highest germination and emergence
were obtained when sowing delay was smallest (3±
4 days) and longer delays will tend to reduce germination and emergence. These observations dispel the
general belief that sowing legumes too early after rice
harvest will result in crop establishment failures due to
waterlogging, particularly when sowing is followed by
rain. However, it is possible that a prolonged period
rain or an excessively heavy rainfall immediately following sowing may result water logging of the seeds
and subsequent germination failure. This happened
repeatedly at San Ildefonso where typhoons occur regularly and the trials were resown after each typhoon.

4. General discussion
The aim of the trial under the rain-shelter was to
determine the effects and interactions of sowing time
and cultivation on germination and emergence of
legumes. Controlled dibbling was used in this experiment similar to treatment T4 in the dibbling trial. The
dibbling trial was intended to examine the effects of
depth of sowing and soil cover on the success of
germination and emergence of legumes, subject to
the normal vagaries of the prevailing climatic conditions, in particular rainfall. During the experiment, 49
and 76 mm of rain fell during the trial at Jambegede
and Ngale, respectively. Sowing in the latter experi-

4.1. The response of seeds to environmental factors
in the laboratory
If the data reported in this paper is to be extrapolated to other soil and climatic conditions, a generalised model of crop establishment needs to be
developed from these data. Assuming an absence of
biotic constraints and no limitation in seed, soil contact, the response of seeds to water potentials and
temperature can be measured in the laboratory, which
can be used as the basis for the development of such a
model. The relationship between these two factors and
germination of the three Indonesian legume cultivars

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

(Y ), can be expressed by the following regression
equations:
Mungbean:
Y ˆ 94:06ÿ23:71…pF†2 ‡ 55:71 pF ÿ 0:0091…pF†2 T 2
‡ 0:46…pF†2 T;
r 2 ˆ 0:89; n ˆ 30
Soybean:
Y ˆ 94:1 ÿ 16:91…pF†2 ‡ 59:07 pF ÿ 0:079…pF†T 2 ;
r 2 ˆ 0:76; n ˆ 30
Peanut:
Y ˆ 95:64 ‡ 30:45…pF†2 ÿ 177:92 pF ÿ 0:34…pF†T 2
‡ 17:83…pF†T ‡ 0:069…pF†2 T 2 ÿ 3:68…pF†2 T;
r 2 ˆ 0:89; n ˆ 30
where pF is the logarithm of the positive value of soil
water potential in cm, and T is temperature in 8C. A
similar relationship was also obtained with Australian
cultivars (Rahmianna, 1993).
Soil temperatures in the seed placement zone during
the ®eld experiment were relatively constant at around
28±338C for the top 20 cm. In Fig. 2, the laboratoryderived functions were plotted for the temperatures 28
and 338C representing predicted germination rates in
response to temperature and water potential of the soil
immediately around the seed. Where predicted germination was greater than 100% as a result of the
quadratic nature of the equations, germination was
assumed as 100%. The symbols in Fig. 2 represent
germination data collected in the ®eld. These were
plotted against the water potential derived from water
contents measured at seed placement depth. The
agreement between measured and predicted germination is good, with some exceptions, e.g. at the lower pF
values (i.e. higher soil water potentials). Mungbean
germination in both the establishment and dibbling
trials at Jambegede (open symbols) between pF 0 and
2.3 were signi®cantly lower than predicted. This
reduction was mainly caused by the high incidence
of seed rot. As mungbean is a common legume crop
grown after rice in the region and at the experimental
site, it is reasonable to assume that suf®cient inoculums are present in the soil that can infect mungbean
seeds. Intact seeds that failed to adequately imbibe,
also contributed to the failure of germination, parti-

79

cularly when mungbean was planted with no seed
cover (T1 and T3) or when planted late (D1) and in the
absence of rain. Predicted mungbean germination for
all treatments at Ngale agrees well with the measured
germination since the incidence of seed rot was very low.
In contrast, predicted soybean germination at Jambegede agrees well with measured germination, but on
the Vertisol at Ngale, lower germination was caused
by seed rot when soybean was planted later than 1
week after rice harvest. Soybean is the preferred
legume after rice in this region with probably a high
population of inoculum compatible with soybean.
Late planting in tilled soils at Ngale resulted in a high
proportion of intact seeds associated with imbibition
from poor seed±soil contact. Compared to the normal
cone-shaped dibbling hole, soybean sown in narrow
holes (T6) showed reduced germination and a high
incidence of seed rot, presumably associated with
higher humidity from this treatment.
Peanut germination in both trials at Jambegede and
Ngale were lower than the predicted germination
associated with a large incidence of either germination
failure or failure of seedlings to emerge. The latter
appears to be due to an inability of seedling roots to
establish into the hard soil that showed as root curling
around the seed. Germination is slower in peanut than
mungbean or soybean. Tillage of the Vertisol at Ngale
created a rough seedbed and hence gave poor seed±
soil contact that increased germination failure in the
establishment trial (22.9%). However, 76 mm of rain
reduced germination failure signi®cantly in the dibbling trial (3.3%). Germination was high when peanut
was planted in zero tilled and wet soil (D0 and D1) at
Ngale. In the lighter soil at Jambegede, germination
failure was generally associated with high numbers of
intact seed. Poor seed and soil contact was also a
problem when peanut was planted without any seed
cover (T1 and T3) in the dibbling trial and 46 mm of
rain at 10 days after planting appears to be too late to
affect germination and establishment of peanuts in this
soil. Poor seed±soil contact is probably a result of the
large seed size.
The effect of sowing depth on establishment is
expected to be through its effect on soil-water content
and temperatures. A survey of farmer's ®elds showed
that depth of planting varied between 4 and 7 cm and
generally tended to be deeper than 5 cm. Soil water
potentials at these planting depths at both sites were in

80

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

Fig. 2. Relationship between germination and water potential for three different legumes from the establishment (ET) and dibbling trials (DT)
at Jambegede (open symbols) and Ngale (closed symbols). Observed germination were derived as the sum of % emergence and % failure to
emerge in Tables 1, 2, 4 and 5.

the range of pF 0±2.8 when predicted germination
should be around 100%. Therefore, planting legumes
up to 7 cm under the conditions at Jambegede and
Ngale should not be limiting. Observed reductions in
actual germination of all species may be associated
with reduced seed±soil contact, high soil strength,

biological constraint (fungal or bacterial infections)
and seed vigour. These reductions can be incorporated
into a simple model where they may be expressed as a
ratio relative to germination with no constraints.
Further work is required to quantify the effect of such
constraints.

A.A. Rahmianna et al. / Soil & Tillage Research 56 (2000) 67±82

5. Conclusions
In conclusion, this work has shown that:
 Generally the effect of mulch on legume germination and establishment in the humid region of East
Java is negligible.
 Tillage of the surface soil has no effect on germination and emergence of legumes in the Andosol at
Jambegede, but in the Vertisol at Ngale tillage
reduced germination and emergence, most probably associated with the cloddy nature of the soil
after tillage.
 Sowing legumes immediately after lowland rice
harvest did not result in waterlogging of the seeds,
even when it is followed by rainfall. On the
contrary it gave the best rate of germination and
establishment. Increasing the delay period between
rice harvest and sowing results in drying of the
soil, particularly after tillage. By itself, the degree
of drying does not affect germination significantly but increased the susceptibility of the
seed to fungal infection resulting in reduced total
germination.
 Germination of mungbean at Jambegede and soybean at Ngale were reduced mainly by seed rot,
most probably associated with the presence of
compatible inoculum population associated with
its previous cropping history. Germination of peanut was limited at both sites largely due to poor
seed±soil contact and an inability of the root to
penetrate the soil.
 The farmer's practice of dibbling without depth
control (range 4±7 cm) and no seed cover are
adequate for mungbean and soybean after lowland
rice in East Java, however, peanut would benefit
from improved dibbling technique such as the use
of cover and a spike to assist the root in penetrating
the puddled soil.

Acknowledgements
The senior author was funded by the Australian
Agency for International Development (AusAID)
postgraduate award and the research was funded by
the Australian Centre for International Agricultural
Research (ACIAR).

81

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