Evaluation of biomass yield and growth performance of alfalfa and oat cultivars in the High Land of Arsi, Ethiopia

C Befekadu and A Yunus

Arsi University, College of Agriculture and Environmental Sciences, PO Box 193, Asella, Ethiopia
befekaduc@yahoo.com

Abstract

The major objective of this study was to investigate the effect of intercropping alfalfa with oat on growth rate, total forage dry matter yield and nitrogen yield. Alfalfa cultivars with or without oat was grown on finely prepared seed beds. The experimental seed was planted on 12 m² plot (4 m long and 3 m wide), consisted of 10 rows with intra-row spacing of 0.3m. The plots were laid out in Randomized complete block design (RCBD) with five replications per treatment. Data on biomass yield and other yield related traits was subjected to the analysis of variance (ANOVA) procedure for RCBD experiments using the General Linear Model (GLM) procedure of SAS computer software packages.

The result of this experiment has shown that the total forage dry matter yield harvested from plots containing a mixture of alfalfa and oat was higher (P<0.05) than other plots containing pure stands of alfalfa and oat. The analysis also indicated that the dry matter yield per area of land was much greater for oat grown with alfalfa than oat grown without alfalfa. In this trial, the leaf to stem ratio of alfalfa and oat plant grown alone was statistically similar (P>0.05) to those grown in a mixture. The average plant height of .alfalfa and oat plant grown in separate plot was not differed (P>0.05) from those grown in a mixture on same plot under this experiment. The chemical analysis result has implied that the dry matter content of each plant (alfalfa and oat) grown in a mixture was higher than those plant grown separately. Likewise, the crude protein content of oat grown with alfalfa on the same plots was improved as compared to those oats plants grown alone in separate plots which could be achieved from the symbiotic relationship between the two plants grown in mixture. In general, the higher quality forage obtained from oat plants grown with alfalfa on the same plots, may be an important consideration for livestock producers.

Keywords: crude protein, forage yield, growth rate, intercropping

Introduction

Feed scarcity in both quantitative and qualitative dimensions is one of the major constraints for the promotion of the livestock sub-sector in Ethiopia (Alemu 1997). In many areas of the country, animals are kept on poor quality natural pasture that commonly occur on permanent grasslands, roadsides, pathways and spaces between cropped plots (Tewodros and Meseret 2013). In the central highlands of Ethiopia (2500–3000 meters above sea level [masl]), grasses and barley straw are major sources of animal feed. However, these feed resources are characterized by high fiber (>55%), low digestibility, low crude protein (< 7%) contents, and poor mineral composition (Seyoum and Zinash 1989, Dereje et al 2010). Moreover, the available grazing lands particularly in the highlands are decreasing in size and quality due to high population pressure and encroachment of cropping on to communal grasslands (Nandi and Haque 1988). These two factors limited the performance of animals fed on poor pastures and cereal straws; since the amount consumed is restricted and the nutritive value per unit of ingested feed is relatively low (Reed et al 1990; Tsige 2000).

One way to optimize utilization of available feed resources is strategic supplementation of crop residues with plant protein sources such as leguminous forage crops which have the potential for alleviating some of the feed shortages and nutritional deficiencies experienced in the dry season on smallholder farms (Hove et al 2001).

Leguminous forage crops have been investigated as potential supplements for ruminants because of their beneficial effect of increasing metabolizable energy intake, N intake and feed efficiency (Teferedegne 2000). As a result, animals with access to leguminous forage crops perform better than those kept on natural pasture in milk yield, weight gain, reproductive performances and survival rates (Norton 1994b; Elbasha et al 1999).

In the existing forage legume germ-plasm selection programs in Ethiopia, more attention has been given to assessment of the environmental adaptation, herbage DM yield potential and seed bearing ability of candidate accession. This suggests the need for research works focusing on characterization of elite forage cultivars grown under varying production systems and agro-ecological conditions to effectively exploit their potential in livestock feeding. Legume cover crops are commonly used for nitrogen contribution because of their inherent capacity to fix atmospheric N (inert gas) into usable form to be used by succeeding crops. A wrong combination of cover crops may exert negative attributes, so a thorough understanding of cover crops selection and management is needed to minimize negative outcomes.

There is very little research that has been carried out on the effectiveness of N2 fixation of indigenous (local) varieties of legumes and the effect of intercropping these legumes with local cereal crops variety in Ethiopia. The major objective of this study were therefore; to investigate the effect of intercropping on growth rate, biomass yield and nitrogen fixation/yield in Arsi highlands of Ethiopia, generating such information has a pivotal role before the candidate genotypes are officially registered as a variety. This study was primarily designed to evaluate the seeding rate (growth performance and biomass yield of Alfalfa as companion crop with Oat cultivars at Arsi University, College of Agriculture and Environmental Sciences, Asella, Ethiopia.

The specific objectives of this study (Experiment) were, therefore, to evaluate; Effect of alfalfa and oat combination on Biomass yield.The Effect of a Companion Crop (Oat) on growth rate of alfalfa. Nitrogen yield: Pure stands vs. mixtures

Materials and methods

Description of the study sites

he experiment was conducted in Arsi University, College of Agriculture and Environmental Sciences; Asella, Ethiopia. The study area is located in Arsi Zone of Oromia Regional State, at about 175 km south-east from Addis Ababa, the capital of Ethiopia, situated at 7⁰ 57’N and 39⁰7’E According to (Birhan 2011); the area has an altitude of 2430 meter above sea level, annual rainfall distribution ranging from 1050-1650mm, and average minimum and maximum temperatures of 10⁰ and 22 ⁰C, respectively. The rainfall pattern of the area is bimodal with short dry season occurring between December and March, and the long rainy season between April and mid October. The dominant soil type in the area is reddish brown clay with about 11.10% of dark soil, and a pH of about 4.2. In the study areas agriculture is the basis of the economy and typically a mixed type; crop- livestock production is practiced.

Treatment and experimental design

Alfalfa cultivars with or without Oat was grown at College of Agriculture and Environmental Sciences forage and pasture research site on finely prepared seed beds. The experimental seed was planted on 12 m² plot (4 m long and 5.3 m wide). Each plot (12 m²) was consisted of 10 rows arranged length-wise in an east-west direction, with intra row spacing of 0.3m. Seeds were dressed with a fungicide before sowing. Then, seeds was hand-drilled at a rate of 4kg/ha and di-ammonium phosphate (DAP) fertilizer was applied at the rate of 100 kg/ha at planting. The plots were laid out in randomized complete block design with five replications per treatment. At early stages of seedling development, weeds were controlled through manual weeding followed by hoeing.

Determination of herbage yield, plant height and leaf to stem ratio

At full bloom stage, described as a stage when open flowers emerge on average of two or more nodes and no seed pods present (Ball 1998). Accordingly, for fresh weight determination, four adjacent middle rows with a net area of 3.2 m² was randomly selected and harvested manually by cutting the plants at about 5 cm above the ground using sickle. The first harvest was taken at the time that an early flowering variety was at the10 percent flowering stage. Subsequent harvests were done at 4 weeks intervals.

Data was collected on the following parameters:

I. Fresh weight and dry weight per plot at each harvest.

II. Leaf-stern-ratio.

III. Percentage flowering.

The fresh weight of the cut biomass was recorded just after mowing using field balance. Then, the harvested biomass was manually chopped into small pieces and a subsample of 200g was taken and dried in air draft oven at 60°C for 48 hours to determine herbage dry matter yield (DMY). For plant height determination, mean height of five randomly selected plants were recorded for each plot. Leaf to stem ratio was determined by separately harvesting a central section of two adjacent middle rows with a sampling area of 0.2 m² (0.5 m length x 0.4 m width), and by partitioning the harvested biomass in to leaf and stem fractions. The fraction was dried using similar procedures described above for herbage DM yield determination. Percentage flowering and ability of plants to set seed naturally were determined by leaving border plants of each plot to overgrow after the third harvest. These border plants were observed for flowering and seed setting. Insects were also observed for their ability to trip flowers to effect pollination. The rate of re-growth was determined by tagging four plants per plot after the second harvest, and measuring their height at weekly intervals until the next harvest was done. Observations were also made on competitiveness with weeds, nodulation and incidence of pests and diseases.

Statistical analysis

Dry matter content of the plants was measured after oven-drying at 60°C, for 24 hours. Yield was expressed as kg of dry matter per plot. Five plants were randomly selected from each plot to collect mean quantitative data. Finally, data on yield and other yield related traits was subjected to the analysis of variance (ANOVA) procedure for randomized complete block design (RCBD) experiments using the General Linear Model (GLM) procedure of SAS computer software packages (SAS 2001).Duncan’s multiple range tests with a 5% probability was used to test the significant differences between treatment means. The ‘contrast’ statement in SAS was used to compare between means for all variables (plots) analyzed.

The model used for data analysis was:

Yij=μ + Ti+ Bj+ εij

Where; Yij is the response variable,

μ = is overall mean,

Ti = is treatment effect

Bj = is block effect and

εij = is random error

Results

Total dry matter yield

The result of this experiment has shown that, the total forage dry matter yield harvested from plots containing a mixture of alfalfa and oat was higher (P<0.05) than other plots containing pure stands of alfalfa and oat. This indicated that the overall yield is not affected by the competition effects of oat as the companion crop, if the oat plant was harvested early at the soft dough stage (Table 2). The analysis of this trial has suggested that the total dry matter yield of alfalfa grown without companion was greater (P<0.05) than those grown with companion plant. However, this difference did not associate with the effect of companion plant on performance of alfalfa; rather it could largely be attributed to the proportion of land used for growing this plant. The land area used for growing alfalfa with companion plant was about half of the land used for growing alfalfa without companion , indicating that the dry matter yield per area of land was greater for alfalfa grown with companion than alfalfa grown without companion.

The analysis also indicated that the total dry matter yield of oat grown alone was maximum (P<0.05) as compared to those grown with alfalfa. Yet, the dry matter yield per area of land was much greater for oat grown with alfalfa than oat grown without alfalfa. The fact that the dry matter content (percent) of each plant (alfalfa and oat) grown in a mixture was higher than those plant grown alone (alfalfa or oat), which could be achieved from the symbiotic relationship between the two plants grown in mixture on a single plot. Meyer (1978) reported that, higher forage yield in the seeding year when alfalfa was established with companion crops than clear seedlings. Optimum seedling rate of oat as a companion crop proves for maximum seasonal yield of alfalfa (Lanini et al 1992). However, (Dixon et al 2005) concluded that cereal grain grown with alfalfa competes with alfalfa seedlings for light, water and nutrients. He also stated that such type of competition reduces yield by 25-30 percent. An oat companion crop was found to be an effective alternative to chemical weed control in seedling alfalfa. This is in line with ( Lanini et al 1992). Hence, it could be possible to infer that using an oat as companion crop to alfalfa would appear to be an excellent method for better total forage dry matter yield and also alfalfa seed establishment.

Leaf to stem ratio

In this trial the leaf to stem ratio of alfalfa and oat plant grown alone was statistically similar (P>0.05) to those alfalfa and oat plant grown in a mixture. This reveals that there was no competition for space, if oat was seeded at 30cm interval in a row with alfalfa. The analysis (Table 3) generally suggested that establishing or developing oat as a companion crop at 30cm interval in a row with alfalfa had no effect on seeding and subsequent alfalfa forage yields. This result is in agreement with Diriba et al (2014), who reported that the effect of cultivar was not substantial (P> 0.05) for leaf to stem ratio. Leaf to stem ratio is an important trait in the selection of appropriate forage cultivar as it is strongly related to forage quality (Juan et al 1993; Kratchunov and Naydenov 1995; Julier et al 2000; Sheaffer et al 2000).

Plant height

The average plant height of alfalfa and oat plant grown in a separate plot was not differed (P>0.05) from those grown in a mixture on the same plot under this experiment (Table 4). This indicates that alfalfa grown with oat on the same plot did not affected by the height and root of oat used as companion crop to obtain sun light and nutrient respectively , if oat was seeded at 30cm interval in a row with alfalfa. Diriba et al (2014) has repored that, cultivar has no significant effect on the stand height and he also suggested that, cooler climates encourages more dormant alfalfa grwoth. However, Meyer and Nudell (2008) indicated that companion crops compete with under seeded alfalfa, which can affect the stand that can be established.

Nutrient composition

The chemical analysis result has implied that the dry matter content of alfalfa grown with companion crop was slightly higher than those grown alone in a separate plot. Conversely, alfalfa grown alone in separate plots had a higher Crude Protein content than those grown in mixture with oat on the same plots. This has indicated that alfalfa grown without companion crop produce higher quality forage as compared to those grown with companion crop. On other hand the crude protein content of oat grown with alfalfa on the same plots was improved as compared to those oat plants grown alone in separate plots. This in turn has indicated that growing oat with alfalfa could enhance the nutritional value of forage obtained from this companion crop. The increase in crude protein content of the companion crop could be attributed to the transfer of nutrients from alfalfa to oat grown on the same plots. This is in line with (Meyer 1978) who reported that clear seedling of alfalfa has better quality forage than companion forages. Anderson and Nichols (1983) and Dixon et al (2005) also indicated that pure stands of alfalfa usually produce the highest crude protein yield than companion crops.

Conclusion

• As integration of low cost feeds to optimize utilization of available feed resources is very important, using oat companion crop during alfalfa establishment found to be viable economically. From the chemical analysis, higher crude protein has been observed from oat grown with alfalfa.

Acknowledgement

The authors would like to acknowledge Korean International Cooperation Agency (KOICA) of South Korea for financial support of this experiment

References

Alemu T 1997 Intercropping of maize with forage, Ethiopia, Journal of Agricultural Science 9 (1):15-22

Anderson B and Nichols J T 1983 "Seeding and Renovating Alfalfa" Historical Materials from University of Nebraska-Lincoln Extension. Paper 1301. http://digitalcommons.unl.edu/extensionhist/1301

Ball S T 1998 Alfalfa Growth Stages Guide A-330. Cooperative Extension Service College of Agriculture and Home Economics, New Mexico State University, Las Cruces, NM http://www.virtual.chapingo.mx/dona/paginaCBasicos/a-330.pdf

Birhan A 2011 Kulumssa Agricultural Research Center, Stations descriptions. May, 2011http://www.eiar/centers.org.et

Dereje F, Seyoum B, Zinash S 2010 Characterizing and predicting chemical composition and in vitro digestibility of crop residue using near infrared reflectance spectroscopy (NIRS). Livestock Research for Rural Development. 8.Volume 22, Article #29. Retrieved January 9, 2014, from http://www.lrrd.org/lrrd22/2/feka22029.htm.

Diriba G, Mekonnen H, Ashenafi M and Adugna T 2014 Biomass yield potential and nutritive value of selected Alfalfa (Medicago sativa L.) cultivars grown under tepid to cool sub-moist agro-ecology of Ethiopia. Journal of Agricultural Research and Development Vol. 4(1). pp. 007-014, January, 2014

Dixon P, Janna K and Tanner J P 2005 Establishing a successful Alfalfa crop. Montana state university extension service, May 2005. http://www.montana.edu/wwwpb/pubs/mt200504.html

Elbasha E, Thornton P K and Tarawali G 1999 An Ex Post Economic Impact Assessment of Planted Forages in West Africa, International Livestock Research Institute Impact Assessment Series 2, International Livestock Research Institute, Nairobi. http://hdl.handle.net/10568/502

Hove L, Topps J H, Sibanda S and Ndlovu L R 2001 Nutrient intake and utilization by goats fed dried leaves of the shrub legumes Acacia angustissima, Calliandra calothyrsus and Leucaena leucocephala as supplements to native pasture hay. Animal Feed Science and Technology 91: 95- 106

Juan N A, Shedder C C, Barnes D K, Swanson D R and Halgerson J H 1993 Leaf and stem traits and herbage quality of multi-foliolate alfalfa. Agronomy Journal 85: 1121-1127.

Julier B, Huyghe C and Ecalle C 2000 Within- and among-cultivar genetic variation in alfalfa: forage quality, morphology and yield. Crop Science 40 (2): 365-369

Kratchunov I and Naydenov T 1995 Estimation of Lucerne forage quality by means of morphological and meteorological data. European Journal of Agronomy, 4: 263-267.

Lanini W T , Steve B O , Ronald N V and Jack P O 1992 Using oats as a companion crop in establishing alfalfa, California Agriculture, Volume 46, Number 4http://ucanr.edu/repository/a/?a=69628

Meyer D W and Nudell R 2008 Companion crops competition, Posted December 2008 http://www.ag.ndsu.nodak.edu/plantsci/forage/compcrop.htm

Meyer D W 1978 Alfalfa Management in North Dakota. North Dakota Farm Research: Vol. 36, No.1, p. 22-28. http://hdl.handle.net/10365/4446

Nandi L A and Haque I 1988 Forage legume in Africa Crop-livestock production system, International Livestock Center for Africa (ILCA) Bultin No. 30: 10-17, ILCA, Addis Ababa, Ethiopia.

Norton B W 1994b Tree legumes as dietary supplements for ruminants. In Forage Tree Legumes in Tropical Agriculture, pp. 192–201 [R.C.Gutteridge and H.M.Shelton, editors]. Wallingford, Oxford: CAB International

Reed J D, Soller H and Woodward A 1990 Fodder tree and Stover diets for sheep: intakes, growth, digestibility and effects of phenolics on nitrogen utilization. Animal Feed Science and Technology 30:39–50

Seyoum B and Zinash S 1989 The Composition of Ethiopian Feed Stuffs, Research Report No. 6. Institute of Agricultural Research (IAR), Addis Ababa, Ethiopia 33pp.

Sheaffer C C, Martin N P, Lamb J F S, Cuomo G R , Jewett J G and Quering S R 2000 Leaf and stem properties of alfalfa entries. Agronomy Journal 92: 733-739.

Teferedegne B 2000 New perspectives on the use of tropical plants to improve ruminant nutrition. Proceeding of the Nutrition Society 59(2): 209-214

Tewodros M and Meseret M 2013 Production Constraints, Farmers Preferences and Participatory on Farm Evaluation of Improved Forage Technologies in Selected Districts of Southern Ethiopia, Greener Journal of Agricultural Sciences ISSN: 2276 7770 Vol. 3 (9), pp. 628-635, September 2013.

Tsige Y H 2000 Livestock feed security and associated impacts on sustainable agricultural development. In: Proceedings of the Seventh Annual Conference of Ethiopian Society of Animal Production (ESAP), Addis Ababa, Ethiopia, 26–27 May 1999. pp 51–61.

Received 15 April 2015; Accepted 15 May 2015; Published 3 June 2015

Go to top