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MICROENVIRONMENTAL EFFECTS ON POTATO AND BEAN YIELDS GROWN UNDER INTERCROPPING SYSTEM

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Abstract

This experiment was carried out at the Faculty of Agriculture Research Station – University of Mu´tah – during summer growing season of 2002, to evaluate the effect of the following micro environmental factors: light interception, air and soil heat unit, soil moisture storage (SMS), evapotranspiraton (ET) and water use efficiency (WUE) on the yields of two potato varieties (Berca and Frisia) -Solanum tuberosum – and bean (local variety) – Phaseolus vulgaris – as they are grown under 1:2 and 2:2 intercropping row arrangement and sole cropping. In addition, land equivalent ratio (LER) was determined to assess the efficiency of intercropping system. The yields of the two potato varieties and bean were higher under intercropping than sole cropping, especially when they are grown under 2:2 row arrangement, where potato "Berca" and,"Frisia" gave an increase in yield of 63.9%, and 70.7% respectively, while bean gave an increase in yield of 70.9%, and 57%, as it was grown with potato "Berca" and,"Frisia" respectively, over the yields of their sole crops. The higher intercropped yields of the two potato varieties "Berca" and "Frisia" were associated with significant reductions in the values of light interception air and soil heat unit compared to the values obtained by the two potato varieties "Berca" and "Frisia" grown under sole cropping. On the contrary, the higher intercropped bean yield production was associated with significant higher values of light interception, air and soil heat unit as compared to the values obtained by bean sole crop. Additionally, the values of SMS and ET for potato and bean grown under intercropping tended to be lower than the values obtained by their sole crop. Moreover, WUE values of potato and bean grown in association were significantly higher than the values of WUE obtained by their sole crop. Further more, the values of total (LER) for potato and bean grown under intercropping were higher than one, which indicates the superiority of intercropping system over the sole cropping system. However, the highest total LER was obtained when both crops were grown under 2:2 intercropping row arrangement, where they gave an increase in the range of 64% to 67% as compared to sole cropping system.
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MICROENVIRONMENTAL EFFECTS ON POTATO AND
BEAN YIELDS GROWN UNDER INTERCROPPING
SYSTEM
R.K. SHARAIHA1, N.A. HADIDI1
1 University of Jordan,
Faculty of Agriculture, Aman,
e-mail: ramzik@ju.edu.jo; tel: 00962777421213
This experiment was carried out at the Faculty of Agriculture
Research Station – University of Mu´tah – during summer growing season of
2002, to evaluate the effect of the following micro environmental factors:
light interception, air and soil heat unit, soil moisture storage (SMS),
evapotranspiraton (ET) and water use efficiency (WUE) on the yields of two
potato varieties (Berca and Frisia) - Solanum tuberosum – and bean ( local
variety) – Phaseolus vulgaris – as they are grown under 1:2 and 2:2
intercropping row arrangement and sole cropping. In addition, land
equivalent ratio (LER) was determined to assess the efficiency of
intercropping system. The yields of the two potato varieties and bean were
higher under intercropping than sole cropping, especially when they are
grown under 2:2 row arrangement, where potato "Berca" and,"Frisia" gave
an increase in yield of 63.9%, and 70.7% respectively, while bean gave an
increase in yield of 70.9%, and 57%, as it was grown with potato "Berca"
and,"Frisia" respectively, over the yields of their sole crops. The higher
intercropped yields of the two potato varieties "Berca" and "Frisia" were
associated with significant reductions in the values of light interception air
and soil heat unit compared to the values obtained by the two potato varieties
"Berca" and "Frisia" grown under sole cropping. On the contrary, the higher
intercropped bean yield production was associated with significant higher
values of light interception, air and soil heat unit as compared to the values
obtained by bean sole crop. Additionally, the values of SMS and ET for
potato and bean grown under intercropping tended to be lower than the
values obtained by their sole crop. Moreover, WUE values of potato and
bean grown in association were significantly higher than the values of WUE
obtained by their sole crop. Further more, the values of total (LER) for
potato and bean grown under intercropping were higher than one, which
indicates the superiority of intercropping system over the sole cropping
system. However, the highest total LER was obtained when both crops were
grown under 2:2 intercropping row arrangement, where they gave an
increase in the range of 64% to 67% as compared to sole cropping system.
Key words: intercropping, potato, bean, microenvironment, land equivalent
ratio
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Intercropping is the agricultural practice of cultivating two or more crops in
the same piece of land at the same time or within the same season. It differs from
sole cropping which entails the cultivation of one crop grown alone in pure stands.
Throughout time and in many parts of the world, intercrop has been used to
improve crop utilization of available sun light, water and nutrients [Willey, 1979].
The improvement of utilization plant resources depend on microclimate
modification created by the two crops selected for intercropping, row arrangement
[Sharaiha and Battikhi 2002, Sharaiha and Hadidi, 2007], climate [Batugal et al,
1990] and soil type [Dongmei et al 2007]. Unfortunately, there is little available
information in regard to the effect of plant resources utilization on intercropping
yield production, especially for potato and bean grown in association under
different row arrangements. However, certain reports indicated that lower light
interception obtained by potato grown with corn, gave beneficial effect on potato
yield [Sharaiha and Battikhi, 2002, Batugal et al., 1990 and Midmore, 1990]. On
the other hand, the yield of potato per plant was reduced [Kuruppuarachchi, 1990],
as well as yield of faba bean [Sharaiha and Gliessman, 1992] under certain shaded
treatments compared to that of un-shaded. Furthermore, the effect of temperature
on intercropped potato yield is variable according to potato variety [Haris, 1990].
Lower temperature associated with high irradiation under short photoperiod
promotes tuber initiation and bulking at the expense of top growth (Midmore
1990). Moreover, Sharaiha and Kluson (1994) reported that both air and soil
temperatures were increased when faba bean was intercropped with peas and
lettuce and thus increasing faba bean yield as compared to its sole crop.
Additionally, higher yield production of potato was not affected by
evapotranspiration and soil moisture storage when it was neither intercropped with
faba bean [Al-Qahwaji, 1995], nor with corn [Sharaiha and Battikhi 2002] On the
contrary, Soetedje et al (1998) indicated that higher evapotranspiration of
intercropped peas and canola was related to their higher yield production as
compared to their sole crop, while Jeiming and Midmore (1990) found that higher
yields of corn intercropped with potato were due to higher soil moisture storage
caused by decreased demand of water after potato maturity. Moreover, water use
efficiency was higher under intercropping system than sole cropping system as it
was indicated by Al-Qahwaji (1995), Soetedje et al (1998), Sharaiha and Battikhi
(2002), Tiruneh (2004), and Sharaiha and Hadidi (2007). However, opposite results
were obtained by Anthony et al (2008) in their study on land equivalent ratio light
interception and water use in annual intercrops in the presence or absence of in-
crop herbicides. These conflicting results are calling for more research in this area.
Therefore, this study was conducted with the objective of investigating the
effect of the following micro environmental factors: air and soil temperatures, light
interception, soil moisture storage, evapotranspiration, and water use efficiency on
the yields of potato and bean as they are grown under intercropping and sole
cropping.
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MATERIAL AND METHOD
An experiment was carried out during summer growing season of 2002 in Rabba
at the Faculty of Agriculture Research Station, University of Mu'tah. The station is
located at altitude of 31.2°N, 35.5°E, with an elevation of 920 m above sea level, and
120 km South of Amman. The soil texture is clay loam; the climate is semi-arid with
mean annual precipitation of 326mm and mean annual temperature of 16.2C. Two
varieties of potato - Solanum tuberosum L. - (Berca and Frisia) and one variety of bean
- Phaseolus vulgaris L. - (local bush bean variety) were planted on March 15th under
intercropping and sole cropping. A randomized complete block design with three
replications was used. The treatments included: 1- pure stand of potato “Berca”; 2- pure
stand of potato “Frisia”; 3- pure stand of bean; 4- 2:1 potato “Berca” /bean intercropping
row arrangement; 5- 2:1 potato “Frisia” /bean intercropping row arrangement; 6- 2:2
potato “Berca” /bean intercropping row arrangement; 7- 2:2 potato “Frisia” /bean
intercropping row arrangement. Each treatment plot consisted of six rows 75cm apart
and 4 meters long. Spacing between plants within row was 35cm and 15 cm for potato
and bean, respectively. Compost poultry manure was applied one week before planting
at the rate of 15Mt.ha-¹. Weeds were kept under control manually. Surface laterals of
16mm diameter were installed on every planting row to deliver water to plants. In line,
drippers with 40cm spacing and 4 liters per hour per dripper discharge rate were used
for irrigation. The amount of water added was recorded by water flow meter. Soil
moisture measurements were taken at 7.5, 22.5, 45 and 75cm soil depth. In addition,
gravimetric method was used to support neutron probe readings for the two first layers.
Two access tubes (90cm long) of two inches diameter were installed within the row
between two adjacent potato and bean plants under intercropping treatments, while
one access tube was installed for each sole crop. Calibration for different soil layers
was correlated with soil moisture counts of neutron probe with gravimetric soil moisture
samples. Linear regression equation for calibration of neutron probe for the third layer
was Pv% = 38.30 CR- 22.08 and that for the fourth layer was Pv% = 29.88 CR – 15.23,
where Pv% is a volumetric moisture content and CR (count ratio) is a neutron probe
reading in the field. Crop evapotranspiration (ET) and soil moisture storage (SMS) were
calculated by using the following equations: - ET= R + I + DSi – DP. Where R : is the
amount of rainfall and it was = 0, I : is the amount of irrigation, Dsi : is the initial soil
moisture content, and DP : is deep percolation and it was = 0.
SMS = increase in soil moisture (+ s) . Where s is the difference between
two neutron probe readings for the soil moisture storage taken after irrigation by 16
hours and before each irrigation. While water use efficiency (WUE) was calculated by
dividing yield over ET. Daily light and temperature (air and soil) measurements (taken
between 11AM and 1PM) started 24 days after emergence using porometer and
thermometer, respectively. However, temperatures were recorded as heat unit, using
the 50-86F؛method as described by Battikhi and Ghawi, (1987). The heat unit method
should indicate which of the treatments provided best temperature for plant growth.
Light measurement was taken at the lower, middle and the upper part of the stem
(averages were calculated). Harvesting date was on July 10 -11 for potato, while for
bean (green pod) started on May 26 – July 9. Yields of both crops were obtained from
the middle three meters of the central four rows, for 2: 2 row combination and from the
middle of the central three rows, for 1: 2 or 2: 1 row combinations. The land equivalent
ratio (LER) was calculated for the combined intercropped yields and for the intercrop
yield of each crop, as described by Willey (1979), who expressed the intercrop yield on
a relative basis to a sole crop yield (i.e. where LER = 1). Analysis of variance for the
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micro environmental values and yield data were determined. The Duncan’s Multiple
Range Test (DMRT) was then employed for means separation.
RESULTS AND DISCUSSIONS
Effect of light interception, soil and air heat unit on the yield of potato
grown under sole croping and intercropping with bean
Table 1 shows the comparison between the averages of light interception, air
and soil heat unit for two potato varieties “Berca” and Frisia” grown under sole
cropping and intercropping with bean. A reduction of light interception, air and soil
heat unit were obtained under potato intercropping as compared to potato sole crop.
The highest significant reduction was obtained when the two potato varieties were
planted with bean under 2:2 row arrangement. However, the reductions of light
interception, air and soil heat unit for potato “Berca” were 66.6 µmol.m² s², 256.2
and 183 respectively, while for potato “Frisia” the recorded reductions were
152.1µmol.m² s², 247.9 and 171.5 respectively, as compared to their sole crops
(table 1).
This could be explained by the higher vegetative growth of potato grown
under intercropping than under sole cropping (data not shown). It seems that the
effect of the associated bean crop under compost poultry manure application -
through fixing atmospheric nitrogen, might be beneficial in terms of an extra
nitrogen contribution to potato vegetative growth during the same growing season,
and consequently, was reflected on the potato tuber yield production. This fact has
been pointed out by many researchers such as Sharaiha and Kkuson (1994) Danso
et. al (1987), Ruschel et. al (1978), Lal et.al (1978) and Wahua and Miller (1978).
However, the highest significant yields of the two potato varieties “Berca and
Frisia” were obtained under 2:2 potato / bean intercropping row arrangement as
compared to their sole crop.
Therefore, the nitrogen fixation by the associated bean crop and the shading
effect created by more vegetative growth in addition to a reduction of air and soil
heat unit (table 1) could be behind the higher significant yield of the two potato
varieties. Similar results were obtained by Al-Qahwaji (1995) and sharaiha et. al
(2004). Moreover, when the two potato varieties “Berca and Frisia” were grown
under sole cropping and intercropping with bean, under the same row arrangement
they gave insignificant differences in yields even though, the values of light
interception and air temperature between the two potato varieties under each
cropping system (2:1 potato bean intercropping; 2:2 potato bean intercropping and
sole cropping) in most cases were significantly different, while soil temperatures
were not significant.
This might indicate that soil temperature is one of the factors which play an
important role in potato yield production. Similar results were obtained by
Midmore (1990) who suggested that higher soil temperatures inhibit the conversion
of sucrose to starch within the tuber and thus, affecting potato yield production.
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Therefore, the insignificancy between the yields of two potato varieties under the
same cropping system could be attributed to insignificant soil temperatures.
Effect of light interception, soil and air heat unit on the yield of bean
grown under sole croping and intercropping with potato
When bean was intercropped with the two potato varieties “Berca” and
“Frisia” under 1:2 and 2:2 row arrangement, the values of light interception, air and
soil heat unit were higher than the values obtained by bean sole crop (table 2).
However, the highest significant values were recorded when bean was planted
with the two potato varieties “Berca” and Frisia” under 2:2 row arrangement,
where bean planted with potato “Berca” gave a significant average increase of light
interception (by 247.5 µmol m²s²), air heat unit (by 27.4) and soil heat unit (by
59.6), while bean planted with potato Frisia” under the same treatment gave an
average significant increase of light interception (by 384.5µmol m²s²), air heat unit
(by 39) and soil heat unit (by 170.1), over the same values obtained by bean sole
crop. The higher values obtained by intercropped bean were due to a reduction in
vegetative growth (data not shown) as bean was competed with the associated
potato crop which is considered more effective in utilizing water and nutrients than
bean crop and that was reflected on lower vegetative growth of intercropped bean.
Therefore, more incident radiation penetrate through bean leaves to soil
surface as compared to bean sole crop (without competition) which have more
vegetative growth and dense canopy with less incident radiation passes through all
leaves along bean stem. This also explains the lower values of soil and air heat unit
for bean sole crop as compared with intercropped bean. On the other hand,
intercropped pod bean yields were significantly higher than yield of bean sole crop,
especially when bean was planted with the two potato varieties “Berca” and
“Frisia” under 2:2 row arrangement, giving an increase of 70.9% and 57%
respectively, over the yield of bean grown as a sole crop (table 2). Apparently,
water and nutrition that were available for bean sole crop in the absence of
competition with potato crop was expressed by more vegetative growth rather than
flower and fruit set and consequently gave lower pod yield as compared to the
yield obtained by bean planted with potato which has less vegetative growth but
higher pod yields.
Similar results were obtained by Delouche (1980) who suggested that excess
of water and nutrient prevent the ability of bean to flower, instead, vegetative
growth was encouraged. Moreover, the yields of intercropped bean under the same
row arrangement were not significantly different, this might indicates that the
benefit of the two potato varieties to bean crop was the same as long as most micro
environmental factors are not significantly different.
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Table 1
Effect of light interception, air heat unit and soil heat unit on yields of two potato
varieties as they are grown under intercropping and sole cropping
ROW ARRANGEMENTS
Average Light
interception
μmol.mˉ²sˉ¹
Average
Air heat unit
Average
Soil heat Unit
YIELD TON /
HA
2 rows potato Berca
1 row
bean 1220.8 cd 2063.1 d 1253.0 b 3.786 b
2 rows potato Frisia
1 row
bean 1305.0 ab 2231.5 c 1299.2 b 3.742 b
2 rows potato Berca 2
rows bean 1190.1 cd 2014.2 f 1181.7 b 4.540 a
2 rows potato Frisia 2
rows bean 1197.5 cd 2033.7 e 1205.0 b 4.390 a
Potato Berca Sole crop 1256.7 bc 2270.4 b 1364.7 a 2.770 c
Potato Frisia Sole crop 1349.6 a 2281.6 a 1376.5 a 2.571 c
Table 2
Effect of light interception, air heat unit and soil heat on bean yield grown under
intercropping and sole cropping
ROW
ARRANGEMENTS
Average Light
interception
μmol.mˉ²sˉ¹
Average
Air heat unit
Average
Soil heat
unit
Yield
Ton / ha
1 row bean/ 2 rows
potato Berca 1233.3 b 2o34.4 c 1354.1 ab 1.267
ab
1 row bean / 2 rows
potato Frisia 1266.7 ab 2030.9 c 1369.6 ab 1.238
b
2 rows bean /2 row
potato Berca 1288.0 ab 2051.4 b 1378.6 ab 1.6oo
a
2 rows bean /2 row
potato Frisia 1425.0 a 2063 a 1489.1 a 1.470
ab
Bean Sole crop 1o40.5 c 2024 c 1319 b 0.936
c
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Effect of soil moisture storage (sms), evapotranspiration (et) and water
use efficiency (wue) on the yield of potato grown under sole croping and
intercropping with bean
Intercropping of both potato varieties “Berca” and “Frisia” with bean did not
give any significant effect on SMS and ET as compared with their sole crops (table
3). However, the values of soil moisture storage and ET tended to be lower under
intercropping than sole cropping. This was expected since the values of soil and air
heat unit were significantly lower under potato intercropping as compared to potato
sole cropping (table 1).
These results are in agreement with the findings of Jeiming and Midmore
(1990) in their review on potato intercropping practices in Western Hubei – China.
On the other hand, yields of both potato varieties were higher under intercropping
as compared to their sole cropping, especially when potato Berca” and Frisia”
were grown with bean in 2:2 intercropping row arrangement where significant
differences in yield were obtained under insignificant higher values of SMS and
lower values of ET (table 3).
However, the associated bean crop which is capable of fixing atmospheric
nitrogen will have a beneficial effect on potato yield crop, in terms of nitrogen
contribution during the same growing season especially when chemical fertilizer
was not applied as it was explained earlier. A side from the lower insignificant
values of SMS and ET obtained by potato intercropping, water use efficiency
(WUE) was increased significantly (table 3). The highest significant values of
WUE were recorded when the two potato varieties “Berca” and “Frisia” were
planted with bean under 2:2 row arrangement, where the intercropped potato
“Berca” gave an increase of 0.96 kg/m³, while the intercropped potato “Frisia”gave
an increase of 0, 83 kg/m³, over the values of WUE obtained by both potato
varieties grown under sole cropping system.
The higher values of WUE obtained under intercropping were due to the
higher yields production of potato and to lower values of ET, since WUE is
calculated by dividing yield over ET. Further more, it is believed that the higher
yields of potato intercropping were due to the interactions among different
significant and insignificant micro environmental factors involved in this study.
Effect of soil moisture storage (sms), evapotranspiration (et) and water
use efficiency (wue) on the yield of bean grown under sole croping and
intercropping with potato
There were no significant differences on soil moisture storage, and ET from
intercropping bean as compared with bean sole crop (table 4), even though, the
differences in soil and air heat unit were significantly lower under bean
intercropping than bean sole cropping (table 2). It seems that the range of
differences in soil and air heat unit for bean grown under the two cropping systems
(intercropping and sole cropping) did not affect SMS and ET as long as irrigation
was applied. On the other hand, bean yields were higher under intercropping than
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sole bean cropping especially when bean was planted with the two potato varieties
“Berca” and “Frisia” in 2:2 row arrangement where a significant increase of 0.664
ton/ha and 0.534 ton/ha respectively, over the yield of bean sole crop (table 4).
Obviously the higher yield production of intercropped bean was not related to these
two factors (ET and SMS).
Table 3
The effect of soil moisture storage (SMS) evapotranspiration (ET) and water use
efficiency on the yields of two potato varieties under intercropping and sole cropping
Row arrangements SMS mm ET mm WUE Kg/m3
YIELD TON /
HA
2 rows potato Berca 1 row bean 258.3 a 251.2 a 1.51 ab 3.786 b
2 rows potato Frisia 1 row bean 252.9 a 260.0 a 1.44 ab 3.742 b
2 rows potato Berca 2 rows bean 244.4 a 232.2 a 1.95 a 4.540 a
2 rows potato Frisia 2 rows bean 264.8 a 253.2 a 1.73 a 4.390 a
Potato Berca Sole crop 221.3 a 278.7 a 0.99 b 2.770 c
Potato Frisia Sole crop 275.6 a 284.7 a 0.90 b 2.571 c
Means followed by the same letter within the same column do not significantly differ
using DMRT at 0.05 levels
Table 4
The effect of soil moisture storage (sms) evapotranspiration (et) and water use
efficiency on the yield of bean under intercropping and sole cropping
ROW
ARRANGEMENTS
SMS
mm
ET
mm
WUE
Kg/m3
YIELD
TON / HA
1 row bean /
2 rows potato
Berca
23.02 a 23.79 a 0.530 b 1.267 ab
1 row bean /
2 rows potato
Frisa
23.41 a 23.00 a 0.541 b 1.238 b
2 rows bean/
2 rows potato
Berca
23.83 a 23.94 a 0.668 a 1.600a
2 rows bean/
2 rows potato
Frisa
23.90 a 23.66 a 0.621 a 1.470 a
Bean
Sole crop 24.06 a 24.22 a 0.386 c 0.936c
Means followed by the same letter within the same column do not significantly differ using
DMRT at 0.05 levels
Therefore, other factors such as the higher significant values of light
interception, soil and air heat unit (table 2) might contribute to the higher yield
production of bean as it was explained earlier.
Similar results were obtained by Vladiermeer (1989), who suggested that the
above ground interaction had more effect on higher yield production than below
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217
ground interaction. These results contradicted the findings of Midmore (1990),
where irrigation was not applied, and agreed with the results obtained by
Al-Qahwaji (1995) in his study on production function determination of row
intercropping between broad bean and potato under Jordan Valley conditions.
Moreover, WUE of intercropped bean was higher than sole bean.
The higher significant values of WUE were obtained when bean was planted
with the two potato varieties “Berca” and “Frisia” in 2:2 row arrangements where
bean planted with potato “Berca” gave an increase of 73% while bean planted with
potato Frisia” gave an increase of 60.9%, over the value of WUE obtained by
bean sole crop. The higher values of WUE obtained under intercropping resulted
from the higher yields of intercropped bean and the lower values of ET.
Efficiency of intercropping
For the purpose of evaluating the efficiency of intercropping treatments with
the sole cropping treatments, the land equivalent ratio (LER) concept was used.
The land equivalent ratio is defined by Willey (1979) as the relative land area
under sole cropping that is required to produce the yield achieved under
intercropping. As such, when 2:1 potato / bean intercropping is considered it means
that potato is occupying 2/3 and bean 1/3 of the land and thus, the relative LER of
potato is equal to 0.67 and the relative LER of bean is 0.33, respectively.
Therefore, the total LER equal to one. This indicates that intercropping is
good as sole cropping. However, when the total LER is greater than one, this
means that more land is required for sole cropping to produce what is producing
under intercropping which in turn indicates the superiority of intercropping over
sole cropping.
Thus, table (5) shows that intercropping treatments of potato and bean gave a
total LER more than one. The increase in efficiency (LER) of intercropping
treatments is the result of complimentary patterns of resource use by the
component crops (Willey 1979; Trenbath, 1976). The efficiency of intercropping
was affected by row arrangement where it gave higher values of LER under 2:2
potato / bean row arrangement than under 1:2 potato / bean row arrangement. This
was expected since each intercropping row arrangement allowed for a special
microenvironment, changing to a certain limit the light interception temperature
and moisture (tables 1, 2, 3 and 4) in addition to nutrition(data not shown). The
positive effect of potato and bean on each other under intercropping system is
observed by their relative LER, specially under 2:2 row arrangement where the two
potato varieties “Berca” and “Frisia” gave a relative LER of 0.819 and 0.854,
respectively, higher than the expected value of relative LER for potato grown as a
sole crop in one half of the land, where it is equal to 0.5. On the other hand, bean
under the same treatment gave 0.855 and 0.785 as it was grown with potato
“Berca” and “Frisia” respectively, higher than expected by 0.355 when bean was
planted with potato “Berca” and 0.285 when bean was planted with potato “Frisia”
as compared to bean sole crop grown in one half of the land. It is clear that both
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crops were benefited from each other and this was termed by Willey 1979; and
Gliessman 1998; as mutual cooperation.
The higher efficiency of intercropping potato and bean might be due to their better
use of the available resources (light, water and nutrients) than under their sole
cropping.
CONCLUSIONS
The results of this study indicated the beneficial effect of intercropping
systems under Rabba region conditions and the following conclusions might be
drawn.
Potato “Berca” and Frisia” gave higher yields under intercropping system
as compared to their sole cropping.
Potato “Berca” seems to have a beneficial effect on yield of bean when they
are grown in 2:2 row combination.
Bean yield seems to have beneficial effect on both potato varieties “Berca”
and “Frisia” when they are grown in 2:2 row combination.
A major cause of yield advantage of potato / bean / intercropping is the
better use of resources (light, temperature and water) as a result of
complementarily effects between the crops involved.
BIBLIOGRAPHY
1. Al-Qahwaji, A., 1995 - Production function determination of row intercropping between
broad bean and potato under different water amounts under central Jordan Valley
condition. M.Sc. Thesis, Univ. of Jordan, Amman.
2. Anthony, R. and R.C., Van Acker, 2008 - Land equivalent ratios, light interception and
water use in annual intercrop in the presence or absence of in-crop herbicides. Agr. J
100:1145-1154.
3. Battikhi, A. and I., Ghawi, 1987 - Muskmelon production under mulch and trickle irrigation
in the Jordan Valley. Hort. Sc. 22(4): 578-581.
4. Batugal, P.A., A., Dela Cruz, H.H., Lebunao and A.M., Khawaja – 1990 - Intercropping
potato with maize in low land Philippines. Field Crops Res. 25:83-97.
Table 5
The relative yields, relative LER and total LER of the two potato varieties (Berca
and Frisia) and bean grown under intercropping system
ROW
ARRANGEMENTS
RelativeYields kg haˉ¹
Potato - Bean
Relative LER
Potato - Bea Total LER
2 rows potato Berca
1 row bean 2.524 - 0.422 0.911 - 0.451 1.36
2 rows potato Frisia
1 row bean 2.495 - 0.413 0.970 - 0.441 1.41
2 rows potato Berca
2 rows bean 2.270 - 0.800 0.819 - 0.855 1.67
2 rows potato Frisia
2 rows bean 2.195 - 0.735 0.854 - 0.785 1.64
Lucrări Ştiinţifice – vol. 51, seria Agronomie
219
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... These crops can enhance soil moisture conservation by covering the soil surface, which significantly reduces water loss through run-off and evaporation (Ogindo and Walker, 2005;Karuma et al., 2011;Chepkemoi et al., 2014;Namoi et al., 2014;Gitari et al., 2017;Singh et al., 2017). Various crops such as maize, sulla, spinach, radish and beans have been intercropped with potato, resulting in increased water use efficiency (Sharaiha and Hadidi, 2008;Rezig et al., 2013;Fan et al., 2016;Singh et al., 2016;Zhang et al., 2016). However, most of these studies focused on potato under non-legume intercropping systems. ...
... However, most of these studies focused on potato under non-legume intercropping systems. Sharaiha and Hadidi (2008) reported higher water use efficiency under potato-bean intercropping under irrigation, and Singh et al. (2016) observed higher potato equivalent yield when potato was intercropped with radish. In Kenya, intercropping of potato with legumes (dolichos, garden peas and beans) has been reported to reduce run-off and soil loss compared with the pure stand of potato (Nyawade, 2015). ...
... Zhang et al. (2016) reported a better water utilization under potato-legume intercropping systems compared to monocropping systems. Sharaiha and Hadidi (2008) and Rezig et al. (2013) reported higher productivity when potato was intercropped with bean and sulla (Hedysarum coronarium L.), respectively compared to the pure stand of potato. The current study, therefore, emphasizes the great potential of potato-legume intercrops that can easily be adopted, especially by smallholder farmers to increase their incomes. ...
... Integration of legume crops into potato production systems might be a viable opportunity that could address these challenges. Intercropping has many advantages such as increased yield, reduced erosion and accelerated nutrient recycling, particularly when crop residues are ploughed back (Ogindo and Walker, 2005;Sharaiha and Hadidi, 2008;Rezig et al., 2013;Nyawade, 2015;Singh et al., 2017). Nevertheless, the role of legumes in influencing water and nutrient utilization under potato-legume-based intercropping systems is not well understood. ...
... Although potato has previously been intercropped with various crops such as maize (Zea mays L.), beans (L.), spinach (Spinacia oleracea L.), sulla (Hedysarum coronarium L.), and radish (Raphanus raphanistrum L.) (Sharaiha and Hadidi, 2008;Rezig et al., 2013;Fan et al., 2016;Singh et al., 2016;Zhang et al., 2016b), there is a dearth of information on potato-legume intercrops. The few studies available that have been carried on potato-legume intercropping systems; only focused on either the effect on light interception and/or the dry matter production efficiency (Rezig et al., 2013) or were carried under advanced technologies such as plastic film mulch, which poor farmers cannot afford (Zhang et al., 2016b). ...
... Declining soil fertility and food insecurity coupled with high poverty levels have compelled farmers to look for alternative interventions of increasing crop production. In addition to sole potato cropping systems, farmers intercrop it with other crops such as maize (Zea mays L.), beans (Phaseolus vulgaris L.), sulla (Hedysarum coronarium L.) and radish (Raphanus raphanistrum L.) (Sharaiha and Hadidi, 2008;Rezig et al., 2013;Fan et al., 2016;Singh et al., 2016;Zhang et al., 2016b). Intercropping is an agricultural practice involving cultivation of multiple crops in the same land either concurrently or within the same cropping season (Sharaiha and Hadidi, 2009;Singh et al., 2016). ...
Thesis
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Integration of legumes into potato-based cropping systems is a common practice in developing countries presumably as a water and nutrient management strategy. This study was conducted to assess the effect of incorporating legumes into the potato production system on soil water conservation, economic returns, nutrients (N and P) use efficiency, and soil physical and chemical properties. Field-based trials were conducted for four consecutive seasons between 2014 short rains and 2016 long rains at the Field Station, University of Nairobi. The treatments comprised of; a pure stand of potato (PS), potato-dolichos (Lablab purpureus) (PD), potato-bean (Phaseolus vulgaris) (PB) and potato-garden pea (Pisum sativum) (PG) intercrops, which were laid out in a randomized complete block design with each treatment replicated four times. The generated data on ground cover, soil moisture content, yield, economic returns, nutrient uptake and use efficiency, and soil physical and chemical properties were analysed using generalized linear models (GLM) in R software version 2.2.3, while means were separated using Tukey’s Honest Significant Difference (HSD) at (p ≤ 0.05). Pearson correlation analyses were applied to determine the relationship between the measured variables. The highest ground cover of 69% was recorded at tuber initiation stage (56 days after planting) in PD compared to 66% in PG and PB and 56% in PS. Similarly, the highest soil moisture content (SMC) values were recorded at tuber initiation stage: 230, 207, 201 and 188 mm m−1 for PD, PG, PB and PS, respectively with significant (p ≤ 0.05) differences between treatments. Nutrient uptake by potato was significantly higher in PS and PD than in PB and PG, which was a reflection of tuber yield that followed the trend of PS (36 t ha−1) = PD (35) < PB (30) = PG (29). When tuber and legume grain yield were converted into potato equivalent yield (PEY), the intercropping systems outperformed the potato pure stand. For instance, PD had significantly (p ≤ 0.05) the highest economic returns of US$ 9,174 ha−1, nitrogen use efficiency of 43 kg PEY kg−1 N supply and phosphorous use efficiency of 169 kg PEY kg−1 P supply. After two years of potato-legume cultivation and incorporation of crop residues into the soil, soil physical and chemical properties at 0.3 m depth such as sand, silt and clay were only influenced by slope position with sand decreasing down the slope whereas, the opposite was observed for silt and clay. Bulk density (BD) was significantly (p ≤ 0.05) above the initial value (1.03 g cm−3) recorded before the start of the experiment and increased down the slope in all treatments with averages of 1.21, 1.14, 1.13 and 1.07 g cm–3 in PS, PB, PG and PD, respectively. PD recorded significantly (p ≤ 0.05) higher pH (5.9), total nitrogen (3.7 g kg–1 N), organic carbon (37 g kg–1), available P (26 mg kg–1) and cation exchange capacity (34 cmolc kg−1) compared to all other intercropping systems. Sand and BD were inversely (r = 0.33–0.84; p ≤ 0.05) correlated with the soil chemical properties such as pH, P, N OC and CEC which in turn were directly (r = 0.38–0.49; p ≤ 0.001) correlated with clay. The data in this study indicate that intercropping potato with L. purpureus is a sustainable production practice that would ensure high tuber yield and improved soil fertility. To cite: Gitari, H.I., 2018. Potato-Legume Intercrop Effects on Water and Nutrients Use Efficiency, Crop Productivity and Soil Fertility in a Humic Nitisol, Kenya. PhD Thesis, University of Nairobi, Kenya. Available at: http://hdl.handle.net/11295/104126
... Rezig et al. (2010) also noted that potato-green bean intercropping systems contributed to an increase in potato yield that they attributed to an increase in water use efficiency (from 8.69 kg m -3 to 10.15 kg m -3 ) and radiation use efficiency (from 4.47 g MJ -1 to 4.77g MJ -1 ) using the sole crop as the baseline. Production of dry matter is reported to depend on efficient water and radiation use (Sharaiha and Hadidi, 2002). In addition, intercropping with legumes contributes greatly to restoration of soil organic carbon stocks, and nitrogen fixation through the activities of the nitrogen fixing bacteria as well as reduced pest and disease pressure (Meena and Lal, 2018). ...
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In Uganda, potato (Solanum tuberosum. L) is an important cash and food crop but its productivity has stagnated at around 3.5 t ha-1 , far below potential (20 t ha-1), mainly due to soil exhaustion resulting from land shortages, and poor agronomic practices. It is vital to enhance production and efficient use of land resources by embracing elements of the systems of crop intensification. The study aimed at generating knowledge on the best combinations of crop management practices to increase productivity and improve land use. A split-split plot randomised complete block experiment was established in the districts of Kabale (high altitude), Rukiga (mid altitude), and Mbarara (descriptor of elevation) for two consecutive seasons (2018B and 2019A). The study investigated the effect of intercropping potato and beans (Phaseolus vulgaris) (in ratios of 1P:1B, 1P:2B, 2P:2B vs. sole potato, and sole bean), at two plant spacing levels (75 cm × 30 cm and 60 cm × 50 cm), and fertiliser usage (NPK and No NPK) on the growth and yield of potato. Results indicated that performance was favourable at high altitude. Intercropping potato and beans at the studied plant densities increased the quantity and quality of potato yield. Whereas the intercrop arrangements of 1P:1B and 1P:2B out yielded sole potato in tuber yield in the favourable highland areas; 1P:1B was at per with sole potato in terms of marketable yield. Intercropping potato with beans in the 108 Makerere University Journal of Agricultural and Environmental Sciences 1P:2B arrangement increased potato yields by 1.2 t ha-1 and also contributed highly to efficient utilisation of land resources (LER = 2.54) compared to sole potato. Addition of NPK increased potato yield, more so at the 75 cm × 30 cm spacing.
... Therefore, to achieve increased P use efficiency in crop production without further increasing fertilizer inputs, there is need to ensure better exploitation of the available soil resources (Rosen et al. 2014;Zhang et al. 2017). Incorporation of legume intercrops into potato cropping systems has been practised previously as a way of soil moisture conservation and/or increasing productivity and profitability of such cropping systems (Sharaiha and Hadidi 2008;Gitari, Gachene, et al. 2018a;Nyawade et al. 2019b). Such practices as intercropping can result in improved nutrients uptake and use efficiency without necessarily incurring extra cost on fertilizers (Gitari, Gachene, et al. 2019b). ...
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Phosphorus (P) is an essential element and its efficient use is of global importance. This study evaluated the effect of growing potato under leg-ume intercrops on P uptake and use efficiency indices: P harvest index (PHI), P uptake efficiency (PuPE), P partial factor productivity (PPFP) and P partial balance (PPB). The experiment was carried out for four consecutive seasons with treatments comprising potato cultivated under legume inter-crops: none (T1), dolichos (Lablab purpureus L) (T2), peas (Pisum sativum L) (T3) and beans (Phaseolus vulgaris L) (T4). Across the seasons, the mean haulm P uptake for T2 (6.7 kg P ha À1), T4 (5.5) and T3 (4.5) were 6%, 23% and 36% lower than that observed in T1 (7.1 kg P ha À1), respectively. On the other hand, tuber P uptake was highest in T1 (21.8 kg P ha À1) and T2 (21.3 kg P ha À1) and were significantly higher than 13.2 kg P ha À1 in T3 and 15.1 kg P ha À1 in T4. This had a profound effect on PuPE, which was equally highest in T1 (0.26 kg total P uptake kg À1 P supply) and T2 (0.25) and lowest in T3 (0.16) and T4 (0.18). Similarly, PPFP, PHI and PPB followed a similar trend, with highest values in T1 (57 kg tuber dry matter yield kg À1 P supply, 76.4 kg tuber P uptake kg À1 total plant's P uptake and 0.20 kg tuber P uptake kg À1 P supply, respectively). Among the tested leg-ume intercrops, dolichos competed least for P with the main crop (potato) hence it can be integrated into potato-based cropping systems without compromising potato tuber yield. ARTICLE HISTORY
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Extensive consumption of chemical fertilizers, herbicides, pesticides and fungicides for crop production has resulted in the reduction of crop quality and introduction of various toxins into the food chains of humans and other organisms. Toxic residues in foods and ecosystems can cause serious human diseases, biodiversity loss, environmental pollution and deterioration of terrestrial and aquatic ecosystem health. Companion planting or mixed cropping refers to growing two or more crops together in a piece of land, and is one of the most important techniques of sustainable agriculture. In mixed cropping, companion crops help each other by several mechanisms such as attracting beneficial insects like pollinators and pest predators, deterring pests and diseases through producing strong scents, natural pesticides and antibacterial, antifungal and antivirus compounds, providing shade and maintaining soil moisture, enriching soil with nutrients such as nitrogen and working as a trap plant, trellis and windbreak. Companion planting can help to produce healthy agricultural crops without using chemicals and as a result conserve human and environmental health and biodiversity.
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To address food insecurity in northern Canada, some isolated communities started gardening initiatives to reduce dependencies on expensive foods flown in to communities. From 2012–2014, soils in northern Ontario James Bay lowlands were cultivated with bush beans and potatoes, grown in sole and intercropping configurations, in an open field and an agroforestry system enclosed by willow trees. The objective of this study was to compare the supply rates of 15 plant-available nutrients in these soils using in situ ion exchange membranes. After three years of cultivation, the agroforestry site had significantly greater supply of PO4, Ca, and Zn and these nutrients had positive correlations with yield. By contrast, the open site had significantly greater supply of Mg, SO4, and B; these nutrients, and Al, had negative correlations with yield. Whilst there were no differences between sole and intercropping configurations, significantly greater supply of NO3, Ca, Cu, Fe, and Zn occurred early in the growing season, compared to significantly greater supply of K, SO4, B, and Al later in the season. Significantly greater yields have been harvested in the agroforestry site and it is suspected that the presence of a willow shelterbelt improves the microclimate and plant-available PO4, Ca, and Zn.
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This experiment was carried out at the Technical Center of Potato (C.T.P) situated in the low valley of Medjerda river at Tunisia, during two growing seasons (2006-2007) and (2008-2009). It aims at evaluating the effect of intercropping potato (Solanum tuberosum cv. Spunta) and sulla (Hedysarum coronarium L. cv. Bikra 21) grown under 1:1 intercropping row arrangement and sole cropping on water consumption and water use efficiency of one potato variety and one sulla variety. In addition, land equivalent ratio (LER) was determined to assess the efficiency of the intercropping system. Intercropping had no significant effect on the above parameters and tuber dry biomass production of potato and sulla. However, it increased the total dry biomass of the intercropping system. This increase occurred during the two cultivating seasons of 2007 and 2009 respectively from 12.5 to 14.8% compared to the potato in sole cropping. Intercropping has led to a similar reduction of water consumption (WC) of both crops. This reduction was 36 and 28% for 2007 and 2009 seasons respectively and for both crops. However, intercropping has led to an increase in the overall (WC) of the mixed system by 9.1 and 13.8% in 2007 and 2009 respectively. Water Use Efficiency (WUE) has been improved from 35.4 to 45.6% for potato in sole intercropping and from 25 to 37.5% for sulla intercropped. The values of total LER were higher than one, which indicates the superiority of intercropping system over the sole cropping system.
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Soybeans (Glycine max L. Merr.) are becoming important in cropping systems that increase competition for light among crops. One of the products of N2-fixation is protein production. A field study was conducted to determine the effects of various degrees of shading (0,20,47, 63, 80, and 93%) on soybean No-fixation, grain yield, and plant composition. The soil was a Flanagan series, a fine, montmorillonitic, mesic Aquic Argiudoll. Ambient illumination was 124.2 klux. Various degrees of shading were obtained by using different screens. Acetylene-ethylene assay was used to determine N2-fixation. Shading accelerated the rate of loss of total nodule Nofixing activity (TNA) as plants developed. The average TNA and dry weight of plant tops were highest at 20% shade (99.3 Klux) and decreased curvilinearly as shading increased, while specific nodule activity decreased linearly. Grain yields under 20, 47, 63, 80, and 93% shade were 90, 75, 48, 18, and 2% of unshaded plants. Seed percent protein and oil content of the seed were virtually unaffected between 20 and 80% shade. The highest percent protein and lowest percent oil occurred at 93% shade. Number of pods per plant percent leaf N, total stem N, TNA, and grain yield were highly correlated with shading and may be good selection indices for soybean shade tolerance. Soybean No-fixation was positively correlated with seed protein content (r = 0.77) but negatively correlated with seed protein (r = −0.44). Cropping practices should allow at least 80% ambient illumination measured at the height of 50 cm for substantial soybean No-fixation. Please view the pdf by using the Full Text (PDF) link under 'View' to the left. Copyright © . .
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The effect of various shade treatments on growth and tuber yield of potato was evaluated at the Agricultural Research Station, Kalpitiya (8°N, 0–5 m a.s.l.) during five Maha (October–March) seasons. Shading experiments consisted of: (a) use of live perennial shade of Ipil Ipil (Leucaena leucocephala); (b) relay cropping with maize and soybeans; and (c) use of artificial and live shade at different growth stages of potato.Ipil Ipil, planted in avenues of 1-m and 2-m width, increased the tuber yield per plant in the first two seasons by 20%, when fully shading the potato crop for one month after planting and two weeks before harvest. In the two successive seasons, yield per plant was reduced in shaded treatments compared to the yield of unshaded controls, although the number of tubers per plant remained the same. This suggests that, as Ipil Ipil matures, competition with potato increases in successive seasons, especially at closer avenue spacings. Avenues 3 m wide, introduced in the last season, improved tuber yield per plant compared to 1-m and 2-m avenues of the same age.In relay-cropping combinations using maize or beans (soybean or polebean) as companion crops, shading during the first four weeks improved tuber yield by 20% whereas shading for up to 6 or 8 weeks after planting the potato reduced the potato yields by 25 and 35%, respectively.Artificial shade (suspended coconut leaves intercepting 50% of the incoming irradiance) during the first four weeks after planting potato, improved total tuber yield by 15% and 20% respectively over live shade (Ipil Ipil or Crotalaria sp.) or unshaded potato yields. However, shading throughout the potato crop, either with live or artificial shade, reduced tuber yield significantly compared to sole potato yields. The benefits of late-season shading were variable, and apparently dependent upon the degree of shading experienced by the potato plants.
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Summary Incubation of 25 and 30 day old nodulated plants ofPhaseolus vulgaris for periods of 24 h and 72 h under 15-dinitrogen atmosphere indicated nitrogen enrichment of soil compared with soil free of plants and with other plants under the same experimental conditions. This indication of release from the root-nodule system is discussed.