Agriculture contributes for the major livelihood and economic growth of Ethiopias. Livestock productions in East African countries challenged by feed scarcity and climate change scenario and their economies are largely depends on climate-sensitive agricultural pro-duction systems. East African regions, including the Ethiopia are highly vulnerable to food and nutrition security. Similarly, increasing feed cost and environ-mental protection issues are some of the challenges facing the livestock industry. In Ethiopia, there was an increasing utilization of Sesbania fodder as a protein source supplement of either grass or poor quality for-age basal diet (Tessema & Baars, 2004).

According to CSA, (2021) Ethiopia report, green fod-der or grazing (54.54%) followed by crop residue (31.13%) are found the major feed resources in the country. Hay and by-products were also contributed about 7.35 and 2.03 percent of the total feeds, respect-tively. About 4.37 percent were also used from other types of feed. However, improved feed resource con-tributions were by far too low that account to about 0.57% of the total feed sources of the country. This indicates further effort required on evaluation of improved cultivated fodder crops that adapt well and productive to the existing environmental conditions. Moreover, according to FAO, (2016) reports, utilization of improved fodder for livestock feed has an advantage of reducing greenhouse gas emission and improve live-stock productivity of the country in a climate-smart manner. Improving productivity and quality through intensive use of improved forage crops cultivation and utilization practices is crucially important. It involves germplasm collection and or introduction of promising forage crops, evaluation for adaptation, yield and qua-lity attributes resistance/tolerance to biotic and abiotic stresses (Aklilu & Asheber, 2019; Hossain et al., 2019). 

Perennial species like Sesbania can be easily establish, well grow in hardy areas and maintain productivity with simple management practices. They have a lot features that make them attractive as multipurpose plants and potentially useful species for agricultural production systems (Gutteridge and Shelton, 1993). In Ethiopian highlands, the multi-purpose tree species of Sesbania sesban is used for livestock feed sources and soil conservation practices. The genus Sesbania con-tains 50 species. According to Gillett, (1963) the grea-test species diversity of sesbania was found in Africa. The specific origin of S. sesban is unknown; however it is widely distributed and grown throughout tropical Africa and Asia countries (Heering et al., 1996). The author also reported the greatest potential of S. sesban for multi-purpose tree and the leaves and young twin-ges are used as high protein fodder for ruminants, while the thick branches and stem provide fuel wood and construction materials. Furthermore it also helps to improve soil fertility and to reduce erosion (Heering and Gutteridge 1992; Degefu et al., 2011). Similarly, Mengistu et al. (2002) reported that screening of multi-purpose tree species like Sesbania species were found higher fodder yield production potentials in the mixed crop-livestock production systems (Nigussie, 2012) of the medium to high altitude areas of the country. 

More importantly, (Orwa et al., 2009; Sabra et al., 2010); stated the high value of fodder nitrogen content of Sesbania sesban (L.) Merr make an important sup-plement to low-protein content roughage diets of ruminant or as substitute for commercial protein supp-lements (Mekoya et al., 2009a). According to Orwa et al. (2009) report crude protein content and In vitro dry-matter digestibility of the foliage is often above 25% and 75%, respectively. The Nylon-bag dry-matter and nitrogen digestibility of dried S. sesban leaf is 90.7% and 96.7%, respectively. In addition to these, the low crude fiber content and high phosphorous levels in-dicate the potential of the species as a high-quality for-age source. Zerihun & Getachew, (2013) reported a sustainable livelihood contribution of S. sesban for household food, nutrition and health security improve-ment. There is limited information of sesbania tree leg-ume lines performance was found under Wondogenet environmental condition. Hence the aim of this rese-arch work is planned to evaluate the performance of three perennial sesbania species, under supplemental irrigation and advice the promising species to be used as a cultivated fodder for livestock feed resources.

Description of the study area

The experiment was undertaken collaborately in Won-dogenet Agricultural Research center and Bangladesh researcher. The center is located at 07°19.1 North lati-tude, 38°30 East longitude of 268 km to the South of Addis Ababa, capital city. The altitude of the area is 1780 meter above sea level. The area receives mean annual rain fall of 1128 mm with minimum and maxi-mum temperature of 11 and 26°c, respectively (Teka-legn et. al., 2017). The texture of the top soil (0-25cm) was sandy clay loam with pH 8.84 (1:2.5 soil water suspensions) and total nitrogen of 0.18.

Treatments and design 

The experiment was conducted in Randomized Com-plete Block Design of three indigenous perennial Ses-bania tree legume lines with three replications. The three treatment lines employed for the study were S. sesban DZF-405, S. dummeri DZF-336 and S. sesban DZF-403. Before establishment, seeds were treated with acid-scarified by soaking in concentrated sulfuric acid for 30 minutes. In order to maintained uniform plant population, seedlings were established in plastic tubes filled with fertile soil. Two seeds were sown per tube and then thinned to one plant. During the first month of establishment, sprinkler water was provided twice every day in the morning and afternoon till the required filled capacity was reached. Then water was applied only once every evening for the second month. A total of nine experimental plots each with 16m2 (4mx4m) areas were prepared for fodder establish-ment. Seedlings were then transplanted into dug plan-ting holes of 30cm wide and 30cm deep spaced 0.5m intra-row and 1.5m inter-row. The plot contained three rows, each consisting of 9 plants (27 plants per plot). The treatment groups were assigned randomly and independently to each experimental block. Manage-ment practices of hand-weeding, pest and disease mon-itoring or control were done uniformly.

Data collection   

The collected data were stand vigor, plant height, late-ral branches less than 50cm and 100cm, diameter, sur-vival per plot, herbage yield, dry matter contents and leaf-to-stem ratio. Plant height, lateral branches less than 50cm and 100cm, and diameter were taken from average of three representative plants per plot from the middle of the rows. Plant height was measured using a graduated steel tape from the ground to the tip of plant. After one season of establishment, the fodder legumes were harvested at a fixed cutting height (0.75 m) that was established as appropriate for Sesbania (Mengistu et al., 2002; Orwa et al., 2009). Similarly lateral bran-ches less than 50cm and 100cm height from the ground level were also counted accordingly. The stand vigor was taken by observational scores of zero to ten (100% vigor). 

Estimation of Biomass and Dry Matter Yield 

Biomass yield of the various perennial Sesbania tree legume fodder lines were harvested at proper stage. Weight of the total fresh biomass yield was measured using spring balance from each plot in the field. Sampled leaf and stem were separated and weighed to determined leaf-to-stem ratio. Subsamples of each 200g of leaf and stem were taken by sensitive balance and sent to the laboratory. Upon arrival at laboratory it was oven dried for 72 hours at temperature of 65°c. The oven dried samples were weighed to determine the total dry matter yield. Then the result was converted in to dry matter ton per hectare for comparison (Aklilu & Alemayehu, 2007; Ali et al., 2022). 

Survival or reaction to diseases and pests 

To determine the survival of the species and reaction to disease and pest tolerance, damaged or died plants were taken by counting the total number of Sesbania trees survived per plot. 

Data Analysis

The collected data were analyzed using General Linear Model procedure of Statistical Analysis System (SAS, 2002- version 9.0). Least significant difference (LSD) test was employed for variables whose F-values de-clared a significant difference (P<0.05). The statistical model for data analysis was -

Yijk = μ + ti + bj + eijk,

Where, 

Yijk is the response variable under examination

μ is the overall mean

 ti is the treatment effect of sesbania tree legume fodders

bj is the block effect/ random effect of experimental plots (j =3; 1, 2, 3) and 

eijk is the random error associated with the observation ij.

Performance of the three perennial Sesbania tree legume lines

The agronomic performances of vigor, height, lateral branches less than 50cm and 100cm, diameter, sur-vival, dry matter ratio, dry matter leaf-to-stem ratio and dry matter yield in ton per hectare were not vary statistically (P>0.05) between three perennial Sesbania tree legume lines (Table 1). However, the two S. sesban lines (DZF-405 and DZF-403) were numeri-cally yield higher dry matter in ton per hectare of 6.23±1.1 and 6.24±1.1, respectively than S. dummeri (3.26±1.1 ton ha-1). The dry matter yield in ton per hectare of this study was found in line with the report of Orwa et al. (2009), who reported yield ranged from 4 to 12 ton ha-1 dry matter per year, depending on location. However Ngasa & Gizahu, (2019) was found a higher average dry matter yield in tone per hectare of five S. sesban (L.) Merril species (17.27) than the pre-sent study (5.25±1.1). Even though S. dumerri yield lower dry matter, it has better leafy branches than the other two S. sesban species (Uddin et al., 2023). 

Table 1: Performance of three perennial Sesbania lines (Mean±SEM).   

Sig= Significant level, ns= Non-significant, CV= Coefficient of Variation, S=Sesbania, SEM= Standard Error of Mean, m= Meter, LB=Lateral Branch, DMR= Dry Matter Ratio, DMLSR= Dry Matter Leaf-to-Stem Ratio, DMYTPH= Dry Matter Yield in Ton Per Hectare.

The dry matter leaf-to-stem ratio were comparable to the result reported by Denbela, (2022) who found 1.13, 1.07, and 1.06 for Sesbania sesban L. species of DZ-0040, DZ-0079 and DZ-32, respectively under supple-mental irrigation condition. However the author repor-ted a higher dry matter leaf-to-stem ratio of 1.27 for DZ-2002 perennial Sesbania species than the present study 1.17±0.1. Concurrently Wubshet et al. (2021) reported higher dry matter leaf- to-stem ratio values (0.23-0.313) of five S. sesban varieties at Highland of Eastern Harerghe. The variation in dry matter yield in ton per hectare as well as its leaf-to-stem ratio might be associated with the genetic materials of perennial Sesbania species, soil types and environmental condi-tions. Likewise, the performance variation contributed due to biological or genetic effects (Megersa & Feyisa, 2016; Elfeel & Elmagboul, 2016; Kebede et al., 2017; Negasu & Gizahu, 2019; Sharmin et al., 2021).

Performance of three Sesbania tree legumes lines during different harvest periods

Harvesting cycle performance of perennial Sesbania tree legume lines were indicated in Table 2. 

The result revealed that higher dry matter yield in ton per hectare (P<0.001) were found during the second harvest (8.7±1.1) than the first (2.19±1.1) and third (4.88±1.1) harvests. Consecutively the dry matter leaf-to-stem ratio were also obtained higher (P<0.001) during the second harvest (1.32±0.1) than the first (0.95±0.1) and third (0.93±0.1) harvests. This might be associated with growing habit of the trees which in-creased productivity at the second harvest and then tend to declined. Regarding to the lateral branches rec-orded at less than 50cm and 100cm, were higher (P< 0.001) during the first harvest (8.2±0.6 and 16.7±0.8) than second (3.3±0.4 and 6.6±0.8) and third (4.4±0.4 and 7.8±0.8) harvests, respectively. This shows that the three sesbania tree legume lines were developed more branches at early stage of maturity than the late stages. But, the diameter was found lower (P<0.001) at the first harvest period (2.9±0.2) than second (4.1±0.2) and third (4.7±0.2) periods. The higher diameter obtained at older age might be due to maturity of the tree legumes. 

Table 2: Performance of three Sesbania lines during three harvesting periods (±SEM).

^abMeans bearing different superscripts along the column differ significantly, Sig= Significant level, **. ***=Significant at 0.01 and 0.001 level, ns= Non-significant, CV= Coefficient of Variation, SEM= Standard Error of Mean, LB=Lateral Branch, DMR= Dry Matter Ratio, DMLSR= Dry Matter Leaf-to-Stem Ratio, DMYTPH= Dry Matter Yield in Ton Per Hectare.

Average dry matter content of three Sesbania tree legume lines

The average dry matter percent of perennial sesbania species tree legume lines across harvesting periods were indicated in Fig. 1. Even though, the result reve-aled that no variations (P>0.05) in dry matter percent values among the lines, the two lines of Sesbania ses-ban DZF-405 and DZF-403 were numerically reco-rded higher dry matter contents of 37.3% and 38.4% during the second harvest periods, respectively. How-ever, Sesbania dummeri DZF-336 line was found better dry matter percent (43.6%) during the first har-vest period (Shahen et al., 2019).

Fig. 1: Average dry matter percent of three Sesbania lines

Average dry matter yield of three Sesbania line over harvesting periods

The average dry matter yield in ton per hectare of the three Sesbania tree legume lines across various harves-ting periods were found highest during the second harvest period (Fig. 2). During this harvest period 9.95, 5.41 and 10.72 ton per hectare of dry matter yield were obtained by Sesbania sesban DZF-405, Sesbania dummeri DZF-336 and Sesbania sesban DZF-403, respectively. 

Fig. 2: Average dry matter yield in ton per hectare of three Sesbania lines.

In contrast, S. dummeri DZF-336 was produced the lowest amount of dry matter yields in ton ha-1 across all harvesting cycles than both S. sesban DZF-405 and DZF-403 tree legume lines. The result revealed that all of the Sesbania tree legume lines dry matter yields were increased during the second harvest period and then tends to decline at the third harvest. This situation might be related with the growth nature of the tree legumes as well as environmental condition of the area.

Average leaf-to-stem ratio of Sesbania tree legume lines

The average dry matter base leaf-to-stem ratio of the perennial Sesbania tree legume lines were showed in Fig. 3. During the second harvest period Sesbania sesban DZF-405, Sesbania dummeri DZF-336 and Sesbania sesban DZF-403 lines were recorded the highest leaf-to-stem ratios of 1.43, 1.41 and 1.13, respectively. 

Fig. 3: Average dry matter leaf-to-stem ration of three Sesbania tree lines.

However the first and third harvest leaf-to-stem ratios of each perennial Sesbania tree legumes fodder were found comparable. Relatively, the leaf parts of the fod-der are more palatable and nutritious than the stem ones. So the higher the leaf-to-stem ratio beats the bet-ter advantage of fodder productivity and quality. The result showed that the two Sesbania sesban (DZF-405 and DZF-403) fodder tree legume lines were better in fodder productivity and qualities at second harvest.

Feed scarcity both in quality and quantity are the major challenges of livestock production. The results indi-cated no statistical variation on the agronomic perfor-mances, dry matter contents, dry matter leaf-to-stem ratios and dry matter yield in ton per hectare among the three perennial Sesbania fodder tree legume lines. However, numerically S. sesban DZF-405 and S. ses-ban DZF-403 were found better dry matter yield in ton per hectare. While Sesbania dummeri DZF-336 yield better in dry matter leaf-to-stem ratio than the two S. sesban species. Moreover, statistically higher dry matter leaf-to-stem ratio and dry matter yield in ton per hectare were obtained during the second harvest period of the fodder legumes. Under supplemental irrigation the varieties are more productive and can give as multiple harvests with minimum of three times per year. It can be utilized as cut-and-carry feeding system as fresh fodder or leaf hay. Therefore, small holder farmers are preferably advice to use S. sesban DZF-405 and S. sesban DZF-403 tree legume fodders under supplemental irrigation of Wondogenet condition.

The authors acknowledge and thank the Ethiopian Institute of Agricultural Research (EIAR) for funding the present research. We are also grateful to Mrs. Desta Fekadu and Mr. Melaku Beshir who were actively in-volved in field management and data collection.

The authors declare no conflict of interest.