Intercropping of legumes and cereals, an old practice since ancient civilization, plays pivotal role to increase land use efficiency, improve income and food production per unit area and minimize the risks of crop failure for small scale farmers. Thus, field experiment was conducted to determine the effect of intercropping of legumes and rates of nitrogen fertilizer on yield and yield components of maize ( Zea mays L.). The experiment consisted of 0, 23, 46, 69 and 92 kg · N · ha - 1 and sole maize, maize + commom bean, maize + common b ean - mung bean cropping systems with Random Complete Block Design factorial experiment in three replications using maize variety, “BH-140”, common bean variety (Hawassadume) and mung bean variety. Maximum plant heights, dry matter and grain yield, were observed from sole cropped maize and maize + common bean, when applying 92 kg · N · ha - 1 . Significantly higher total Land Equivalent Ratio of 2.2, Gross Monetary Value of 87,191 birr ha - 1 , Monetary Advantage of 47,068.2 Birr ha - 1 , total productivity (80,568.49 birr) and net return (55,214.0 birr) were recorded from maize + common bean - mung bean. The, maximum marginal rate of return was obtained from maize + common bean - mung bean and applying 69 kg · N · ha - 1 (1080%). Thus, farmers should be advised to practice cropping of maize + common bean - mung with 69 kg · N · ha - 1 to get economical maize production.
Agriculture is a fundamental instrument for poverty reduction, food security, and economic growth. Almost 80% of the Ethiopia’s populations living in rural areas were directly or indirectly linked to agriculture for their livelihood [
World population is exponentially growing indicating the need for an attractive strategy for increasing productivity to fulfill their food requirements such as intercropping. Intercropping is a practice of advanced agro technique of cultivating two or more crops in the same space at the same time for decades where the goals of agriculture have been achieved.
Maize (Zea mays L.) is the most important cereal after wheat and rice with regards to cultivated area in the world [
But the growing of urbanization and salinization due to improper agricultural land management decreased maize production per unit area each year [
In addition legume-based cropping system showed 20% to 67% yield benefit of intercropping over sole crop and saved 38% more farm land [
Farmers around the study area were practicing cereal legume intercropping with respect to food harvest but not from the knowhow legume contribution to production, and fertilization. However, the integration of legumes and cereals could significantly contribute to food production and through soil fertility improvement [
These practices in some pockets of land at different parts of the regions were not supported with research findings. Knowledge on combined effects of maize + common bean − mung bean under different rate of fertilizer and benefits of legumes under intercropping system was required in the study area. So the aim of this study was to determine theeffect of intercropping of legumes and rates of Nitrogen fertilizer on yield and yield components of Maize (Zea mays L.)
The study was conducted at Chano Mille Kebele of Arba Minch zuriaWereda, Gamo-Gofa zone from August to mid January during 2015/16 cropping season. The study area is situated at an elevation of 1216 m.a.s.l., and between 5˚42' and 6˚13'N and 37˚19' and 37˚41'E latitude and longitude ranges, respectively [
The total rainfall during the growing period, (August to mid January 2015/16) was 614.6 mm the average minimum and maximum air temperatures during the cropping season was 17.4˚C and 33.20˚C, respectively [
A physical and chemical property of soils of the experimental site from a composite soil sample of 0 - 30 cm depth was analyzed and the result is presented in
The experiment consists three levels of cropping systems (sole maize, maize intercropped with common bean, and maize inter cropped with mung bean after common bean harvested) and five levels of nitrogen fertilizer rates (0, 23, 46, 69, 92 kg∙N∙ha−1). The cropping systems and levels of N fertilizer rates were combined in factorial randomized complete block design with three replications. The
Soil depth (cm) | pH | EC ds∙m−1 | OC (%) | N (%) | Available P (ppm) | CEC Cmol (+) kg−1 | Texture |
---|---|---|---|---|---|---|---|
0 - 30 | 6.9 | 0.24 | 1.5 | 0.13 | 13.3 | 45.8 | Loam |
combinations of treatments were as follows:
Sole Maize with 0 kg∙N∙ha−1
Sole Maize with 23 kg∙N∙ha−1
Sole Maize with 46 kg∙N∙ha−1
Sole Maize with 69 kg∙N∙ha−1
Sole Maize with 92 kg∙N∙ha−1
Maize + common bean with 0 kg∙N∙ha−1
Maize + common bean with 23 kg∙N∙ha−1
Maize + common bean with 46 kg∙N∙ha−1
Maize + common bean with 69 kg∙N∙ha−1
Maize + common bean with 92 kg∙N∙ha−1
Maize + common bean with mung bean with 0 kg∙N∙ha−1
Maize + common bean with mung bean with 23 kg∙N∙ha−1
Maize + common bean with mung bean with 46 kg∙N∙ha−1
Maize + common bean with mung bean with 69 kg∙N∙ha−1
Maize + common bean with mung bean with 92 kg∙N∙ha−1
The experiment was conducted with BH-140 maize variety, common bean (variety Hawassadume) and Mung bean (variety shewarobit). The seeds of maize cultivar were planted at inter and intra-row spacing of 75 and 25 cm. The seeds of common bean were intercropped at the same time with maize in between two consecutive maize rows at inter and intra-row spacing of 37.5 and 10 cm. The seeds of mung bean, for treatments 11 to 15, were planted after harvesting common bean. Each plot had a size of 2 × 3 m2 consisting 4 rows for maize, 3 rows for common bean and 3 rows for mung bean. The experimental plots within a block and blocks were spaced at 0.5 m and 1m, respectively. Sole maize was planted within 2 m × 3 m length plot size having inter and intra-row spacing of 75 and 25 cm. Two central rows with net plot size of 2.25 m2 were harvested and used for data collection. Under intercropping condition maize was planted with the same plot size as that of sole maize.
Recommended phosphorus fertilizer rate of 46 kg P2O5 ha−1 in the form of TSP was applied for both sole and intercropped crops as basal application during sowing for easy establishment of crops. Specified rates of nitrogen in the form of urea at 0, 23 , 46, 69 and 92 kg∙ha−1 was applied once a time to all treatments as side dressing when the maize crop reached knee height.
During the cropping season data of days to 50% emergence, days to tasseling, days to silking, days to maturity (dm), plant height (cm) and dry matter production (kg∙ha−1) were collected.
Number of ears per plant, Ear height (cm), Number of kernels per ear, Hundred kernels weight (g), Grain yield (kg∙ha−1) and Harvest index were collected at the time of data collection.
Land equivalent ratio compares the yields from growing two or more crops together with yields from growing the same crops in monocultures [
where, Yni is the yield of each crop or variety in the intercrop and Ymi is the yield of each crop or variety in the sole crop or monoculture.
Average or maximum sole crop yields at the optimum fertilizer used as standardization factors for all mixture plot yields of maize as described by [
Gross monetary value (GMV) was calculated as a product of yields of component crops (kg∙ha−1)) multiplied by their respective price of maize, common bean and mung bean. The price was taken from local markets and monetary advantage (MA) was calculated as:
The economic advantage of the cropping systems was evaluated by estimating net benefit, total cost and marginal rate of return according to [
Statistical analysis of variance of the field experimental data of various parameters was carried out using PROC GLM procedure [
As indicated in
Treatment | Days to 50% emergence | Days to 80% tasseling | Days to 80% silking | |
---|---|---|---|---|
N rate (Kg∙ha−1) | ||||
0 | 9.7a | 73.4c | 79.3c | |
23 | 9.7a | 74.1bc | 80.1bc | |
46 | 9.2a | 74.4ab | 80.8ab | |
69 | 9.4a | 74.6ab | 80.8ab | |
92 | 10.2a | 74.9a | 81.4a | |
SEM (±) | 0.6 | 0.3 | 0.3 | |
LSD(0.05) | NS | 0.7 | 0.9 | |
Cropping Systems | ||||
SM | 9.9a | 74.3a | 80.1a | |
M + CB | 9.2a | 74.2a | 80.7a | |
M + CB − MB | 9.8a | 74.4a | 80.7a | |
SEM (±) | 0.5 | 0.2 | 0.3 | |
LSD(0.05) | NS | NS | NS | |
CV (%) | 19.3 | 1.0 | 1.3 | |
Mean | 9.6 | 74.3 | 80.5 | |
Where SM = Sole maize; M + CB = maize intercrop with common bean; M + CB − MB = maize intercrop with common bean and mung bean; NS = Non-significantly different at 0.05 probability level; Means followed by the same letters were not significantly different at 0.05 level of significance.
with findings by Moges (2015), who indicated that increasing N from 0 to 128 kg∙N∙ha−1 showed consistent increment of days to tasseling [
The mean number of days to attain silking was significantly (P < 0.05) affected by the nitrogen rate but effect of cropping systems was not significant (
The result showed that plant height was significantly (P < 0.05) affected by N fertilizer rate and cropping system is presented in
Treatment | Plant Height (cm) | Days to physiological maturity (days) |
---|---|---|
N rate (Kg∙ha−1) | ||
0 | 204.3d | 142.7d |
23 | 221.8c | 142.7d |
46 | 229.0b | 145.2c |
69 | 236.4a | 146.7b |
92 | 242.4a | 150.3a |
SEM (±) | 2.2 | 0.5 |
LSD(0.05) | 6.3 | 1.4 |
Cropping Systems | ||
SM | 231.6a | 145.8a |
MZ + CB | 224.7b | 145.3a |
MZ + CB − MB | 224.0b | 145.5a |
SEM (±) | 1.7 | 0.19 |
LSD(0.05) | 4.9 | NS |
CV | 2.9 | 1.0 |
Mean | 226.8 | 145.5 |
where SM = sole maize; M + CB = maize intercrop with common bean; M + CB − MB = maize intercrop with common bean and mung bean; NS = Non-significantly different at 0.05 probability level; Means followed by the same letters were not significantly different at 0.05 level of significance.
with no fertilizer (0 kg∙ha−1) applied. The result suggested that plant height was increased with increasing application of nitrogen fertilizer. The present findings was in agreement with the findings by Haseebur et al. who described that cultivation of maize alone with full dose of nitrogen showed maximum (216.5 cm) plant height whereas, minimum height of maize 184.5 cm was recorded from no fertilizer application [
Effect of plant height was significant due to cropping system (
The results of regression analysis as depicted at
As indicated in
tion. The result showed that maximum (150.3) days to reach maturity was recorded from 92 kg∙N∙ha−1 whereas, the minimum (142.7) days to reach DPM was recorded for the control treatment. This finding was in agreement with a result obtained from a study conducted at Haromaya district by Kidist who observed significant effect of increasing nitrogen fertilizer effect on days to physiological maturity where plants in a control treatment matured early, while plants at the highest N rates matured lately [
Application of nitrogen fertilizer showed significant (P < 0.05) effect on kernel number per plant is presented in
Treatment | Kernel Number per ear | Number of ear per plant | Ear height per plant (cm) |
---|---|---|---|
N rate (Kg∙ha−1) | |||
0 | 307.7c | 1.3a | 106.2c |
23 | 357.6b | 1.3a | 115.8ab |
46 | 381.6ab | 1.2a | 120.4a |
69 | 395.4ab | 1.2a | 109.8bc |
92 | 420.2a | 1.2a | 120.1a |
SEM (±) | 14.6 | 0.1 | 2.7 |
LSD(0.05) | 42.3 | NS | 7.8 |
Cropping System | |||
SM | 383.4a | 1.1a | 120.8a |
MZ + CB | 361.9a | 1.3a | 117.6a |
MZ + CB − MB | 372.3a | 1.3a | 104.9b |
SEM (±) | 11.3 | 0.1 | 2.1 |
LSD(0.05) | NS | NS | NS |
CV (%) | 11.6 | 24.9 | 7.0 |
Mean | 372.5 | 1.2 | 114.5 |
Where SM = sole maize; M + CB = maize intercrop with common bean; M + CB − MB = maize intercrop with common bean and mung bean; NS = Non-significantly different at 0.05 probability level; Means followed by the same letters were not significantly different at 0.05 level of significance according to LSD test.
by Lawrence and Dawadi who described Nitrogen fertilizer application showed significant effect on maize kernel number per cob [
Application of nitrogen showed a linear response to kernel number per ear (
As presented in
Mean ear height per plant was significantly affected due cropping system. The mean height was ranged from 104.9 cm to 120.8 cm where the maximum ear height was recorded from sole cropped maize which was on par with maize intercropped with common bean (MZ + CB). The result suggested that ear height per plant was affected due to increased population per unit area which increased competition among the component crops. The present findings was in agreement with the findings by Farzaneh et al. who observed high ear height in sole cropped maize while the minimum in maize intercropped with faba bean [
The relationship between the rate of fertilizer application and cropping system with ear height per plant is depicted in
Analysis of grain yield as affected by fertilizer application and cropping system is presented in
Significant responses of maize was observed at highest level of nitrogen application was also documented by Habtamu, Rashid et al. and Siame et al. [
Treatment | Grain Yield (Kg ha-1) | Dry Matter (kg ha-1) | Hundred Seed Weight (g) | Harvest Index (HI) |
---|---|---|---|---|
N rate (Kg∙ha−1) | ||||
0 | 3731.3d | 10272.2c | 30.2b | 25.7d |
23 | 4429.2c | 10698.9b | 30.2b | 28.8c |
46 | 4761.6bc | 10894.0ab | 31.5ab | 30.4bc |
69 | 5032.7ab | 10814.1ab | 31.8a | 31.0ab |
92 | 5345.1a | 11081.8a | 33.6a | 32.2a |
SEM (±) | 118.1 | 114.4 | 0.9 | 0.6 |
LSD(0.05) | 344.7 | 331.5 | 2.5 | 1.8 |
Cropping System | ||||
SM | 4838.2a | 11166.8a | 30.55 | 29.9a |
MZ + CB | 4843.3a | 10655.7b | 32.64 | 29.7a |
MZ + CB − MB | 4298.5b | 10434.2b | 31.18 | 29.3a |
SEM (±) | 102.1 | 110.7 | 0.7 | 0.5 |
LSD(0.05) | 267 | 256.8 | NS | NS |
CV | 7.6 | 3.2 | 8.2 | 6.2 |
Mean | 4659.1 | 10752.2 | 31.4 | 29.6 |
Yield is adjusted to 12.5% moisture content; SM = sole maize; M + CB = maize intercrop with common bean; M + CB − MB = maize intercrop with common bean and mung bean; NS = Non-significantly different at 0.05 probability level; Means followed by the same letters are not significantly different at 0.05 level of significance.
[
Alemayehu et al. also reported that maize grain yield was 16% more on maize- narrow leaf lupine intercropping relative to sole crop maize studied on Maize- common bean/lupine intercrop productivity and profitability in maize-based cropping system of Northwestern Ethiopia [
The regression analysis result depicted in
As presented in
The maximum dry matter of 11,168.8 kg∙ha−1 was obtained from sole cropped maize. The present finding coincides with the reports documented by Zeljko et al. [
mono crops maize (21.2 t∙ha−1) suggesting advantage of sole cropped maize for growth resources in ability of competition.
The result of regression analysis is depicted in
Harvest index was significantly (P < 0.05) affected by application of nitrogen (
The result of regression analysis is depicted in
Correlation analysis between grain yield and yield components of maize, phenological and growth parameters was worked out and presented in
DEM | DTS | DSI | DMA | PH | DMT | EHPP | NEPP | KNNP | GYLD | HSW | HI | |
---|---|---|---|---|---|---|---|---|---|---|---|---|
DEM | 1 | |||||||||||
DTS | 0.1ns | 1 | ||||||||||
DSI | 0.4ns | 0.3ns | 1 | |||||||||
DMA | 0.4ns | −0.1ns | −0.0ns | 1 | ||||||||
PH | 0.9ns | 0.1ns | 0.5ns | −0.1ns | 1 | |||||||
DMT | 0.4ns | 0.2ns | 0.4ns | 0.9ns | 0.0ns | 1 | ||||||
EHPP | 0.2ns | 0.2ns | 0.7ns | 0.5ns | 0.0ns | 0.8* | 1 | |||||
NEPP | 0.1ns | 0.0ns | 0.5ns | 0.2ns | 0.0ns | 0.6ns | 0.8** | 1 | ||||
KNNP | −0.1ns | 0.2ns | −0.8ns | 0.3ns | 0.1ns | −0.6ns | −0.9** | −0.6ns | 1 | |||
GYLD | 0.5ns | 0.2ns | 0.4ns | 0.8** | 0.1ns | 1.0*** | 0.8ns | 0.5ns | 0.6ns | 1 | ||
HSW | 0.4ns | 0.1ns | 0.4ns | 0.8 | 0.0ns | 1.0*** | 0.8** | 0.7ns | −0.6ns | 0.9*** | 1 | |
HI | 0.5ns | 0.1ns | −0.1ns | 0.7* | − 0.0ns | 0.7ns | 0.4ns | 0.4ns | −0.1ns | 0.7ns | 0.8* | 1 |
Where; DEM = days to emergency; DTS = Days to tasseling; DSI = Days to silking; DMA = Days to maturity; PH = Plant height; DMT = Dry matter; EHPP = Ear height per plant; NEPP = Number of ear per plant; KNNE = Kernel number per ear; GYLD = Grain yield; HSW = Hundred seed weight; HI = Harvest index; NS, *, ** and *** = non-significant and significantly different at 0.05%, 0.01% and 0.001% respectively.
between grain yield and yield components of maize while the association of yield with phenological and growth parameters showed not significant but positive except days to physiological maturity.
Grain yield was significantly and positively correlated with above ground biomass (r = 1.0**), HSW (r = 0.9**) and HI (r = 0.88**) which suggested significant contribution of yield components on grain yield of maize. This finding was similar with a result obtained from a study conducted at Haromaya district by Kidist who observed a positive correlation of grain yield and biomass yield. Significant and positive correlation was also observed between hundred seed weight and above ground dry matter (r = 1.0**) and ear height per plant (r = 0.8**) and negative and non significant correlation with number of kernel per ear (−r = 0.6).
The productivity advantage of maize + common bean and maize + common bean with mung bean intercropping system was assessed with land equivalent ratio and monetary value of the treatment combination. As shown in
The effect of intercropping system was significant for LER when the maximum LER 1.0 was recorded at Maize + Bean cropping system. Maize + Bean cropping system greater than by 20% compared to maize + common bean − mung bean. The result suggested that maize yield advantage decreased with increase in the no of legumes in the cropping system.
Total LER was also significantly affected by the cropping system. The maximum (2.2) total LER was recorded from Maize + Common Bean-Mung Bean. Intercropping three cropping species was greater by 40% compared to intercropping of two crop species. This result agreed with the findings by chemeda who indi-
Treatments | Maize LER | Bean LER | Mung Bean LER | Total LER | GMV Birr∙ha−1 | MA Birr∙ha−1 |
---|---|---|---|---|---|---|
N rates (kg∙ha−1) | ||||||
0 | 67,015d | 28,371d | ||||
23 | 75,341c | 36,641c | ||||
46 | 76,104c | 37,675c | ||||
69 | 80,731b | 42,297b | ||||
92 | 83,662a | 45,368a | ||||
SEM (±) | 864.4 | 849.7 | ||||
LSD(0.05) | 2568.2 | 2524.5 | ||||
Cropping System | ||||||
SM | 31,448.1c | |||||
MZ + CB | 1.0a | 0.8a | 1.8b | 65,950.8b | 29,072.5b | |
MZ + CB − MB | 0.8b | 0.9a | 0.5a | 2.2a | 87,191.0a | 47,068.2a |
SEM (±) | 0.02 | 0.0 | 0.1 | 0.0 | 546.7 | 537.4 |
LSD(0.05) | 0.1 | 0.9 | 0.0 | 0.0 | 1624.3 | 1596.6 |
CV (%) | 7.6 | 4.9 | 16.8 | 2.7 | 2.8 | 5.5 |
Mean | 0.9 | 0.8 | 0.2 | 2.0 | 76,570.9 | 38,070.4 |
Where LER = Land equivalent ratio; GMV = Gross monetary value; MA = Monitory advantage; Means followed by the same letters are not significantly different at 0.05 level of significance according to LSD test.
cated 28% total productivity increase of maize-bean intercropping compared to pure stand [
Similarly, yield advantages of intercropping on maize was in other study conducted at Kombolcha on system productivity of forage legumes intercropped with maize and performance of the component crops [
Significant effect of fertilizer application and cropping system also noted on gross monetary values (
Significant effect of fertilizer application and cropping system also noted on monetary advantages (
Economic analysis of fertilizer application and legumes under maize based cropping system analyzed and presented in
As presented in
Treatment | TVC (Eth. Birr) | NB(Eth. Birr) | MRR% |
---|---|---|---|
SM | |||
0 | 0 | 19,561 | - |
23 | 715 | 26,119.3 | 917 |
46 | 1630 | 28,269.8 | 235 |
69 | 2445 | 29,475.9 | 148 |
92 | 3260 | 30,040.7 | 69 |
M + CB | |||
0 | 0 | 22,568 | - |
23 | 9058 | 47,839.8 | 279 |
46 | 9843 | 49,505.5 | 212 |
69 | 10,658 | 51,710.7 | 270 |
92 | 11,523 | 54,123.4 | 279 |
M + CB − MB | |||
0 | 0 | 23,561 | - |
23 | 22,938.7 | 50,816.7 | 119 |
46 | 23,730.5 | 49,678 | D |
69 | 24,162.6 | 54,346.2 | 1080 |
92 | 25,354.5 | 55,214 | 73 |
SM = Sole maize; M + CM = Maize intercropped with common bean; M + CB − MB = Maize intercropped with common bean and mung bean; TVC = Total variable cost; NB = Net benefit; D = Dominance and MRR = Marginal rate of return.
southern Ethiopia by Walelign (2013) who observed highest net return from sequential intercropping of common bean and mung bean with maize.
Maximum marginal rate of 1080% was recorded when maize intercropped with common bean followed by mung bean when applying 69 kg∙ha−1 nitrogen showed above the minimum (100%) rate of return needed for adoption by farmers [
Greater economic returns were reported in cereal?legume intercropping systems [
The result of this study showed that days to maturity, teaseling, silking and kernel number were significantly affected by the main effects of nitrogen rate at 92 kg∙ha−1. In addition grain yield, dry mater and plant height were significantly affected by both the main effects of cropping system and rate of nitrogen fertilizer. The maximum grain yield, dry mater and plant height were observed in maize + common bean cropping system and sole maize at 92 kg∙ha−1 Nitrogen rate respectively. The maximum partial LER was recorded when maize intercropped with common bean. Higher (2.2) total LER were recorded in Maize + common bean with mung bean cropping system. Maximum gross Monetary Value (GMV) of 83,662 Birr ha-1 and 87,191.0 Birr∙ha−1 were obtained when applying nitrogen at 92 kg∙N∙ha−1 and maize intercropped with common bean followed by mung bean cropping system respectively. Results of economic analysis showed that maize intercropped common bean followed by mung bean with nitrogen at 92 kg∙N∙ha−1 gave higher total productivity (80568.49 birr) and net return (55,214.01 birr). Whereas, higher marginal rate of return (1080%) was obtained from maize intercropped with common bean followed by mung bean with nitrogen at 69 kg∙ha−1.
I would like to express my deepest gratitude and sincere thanks to Dr. Zenebe Mekonnen and Dr. Dereje Tsegaye for their guidance and constructive comments at all stages of the research work and thesis write up. Next, I would like to thank Arba Minch Agricultural Research Center for their financial and technical supports. I am also forwarding my heartfelt thanks to Arba Minch University Department of Plant Sciences for their technical support.
Takele, E., Mekonnen, Z., Tsegaye, D. and Abebe, A. (2017) Effect of Intercropping of Legumes and Rates of Nitrogen Fertilizer on Yield and Yield Components of Maize (Zea mays L.) at Arba Minch. American Journal of Plant Sciences, 8, 2159-2179. https://doi.org/10.4236/ajps.2017.89145