Search

This study was conducted to evaluate the effects of green fodders, fresh Sesbania sesban, and reed grass, on growth performance, blood metabolites, and meat quality of growing lambs. Twenty-one male Farafra lambs (19.0 ± 1.87 kg body weight) were randomly distributed into three groups, each with seven animals. The first group was fed on 60% concentrates and 40% fresh alfalfa, and served as a control. The second and third groups were fed also on 60% concentrates plus 40% fresh Sesbania sesban and reed grass, respectively. Lambs were fed the diets until reaching the target slaughter weight of about 50.0 kg, which was obtained after a period of 215 days. Five lambs from each group were randomly selected and slaughtered at the end of the experiment. Slaughter body weight, carcass traits weight, and dressing percentage were estimated. Chemical composition and physical properties of longissimus dorsi muscle, from the animals’ right side, were determined. It was found that no significant (P > 0.05) differences among groups in body weight, average daily gain, feed conversion rate, hot carcass, dressing percentage, and carcass components were observed. The forage intake of Sesbania and alfalfa tended to be higher than that of reed forage. There were no significant (P > 0.05) differences in the blood parameters among the treatments, except the urea level which was higher in Sesbania sesban group than the reed one. However, the serum urea concentration in Sesbania and reed groups was similar to that of alfalfa. Sesbania sesban and reed forages decreased (P < 0.05) the eye muscle area and shear force in lambs when compared to the control group. The longissimus dorsi muscle of the Sesbania and reed treatments was found to be numerically higher in the moisture and lower in the fat and collagen contents than the alfalfa group. Most of meat and fat color parameters were improved by feeding of Sesbania and reed forages. In conclusion, Sesbania sesban or reed grass, as unconventional forage sources, can be used as alternatives of the commonly used alfalfa feed. Moreover, these sources could enhance the meat quality of lambs and increasing the tenderness with accepted meat and fat color. So, it can be recommended to use Sesbania or reed grass forages in diets of sheep, to overcome the rising in the price or shortage in the availability of traditional green fodders. [ABSTRACT FROM AUTHOR]

This experiment was conducted to investigate effect of dried Sesbania sesban leaves supplementation on milk yield, feed intake and digestibility of Holstein Frisian X Zebu (Arado) crossbred dairy cows. Twelve cows at midlactation (155.83 ± 4.49 days of lactation), second parity, and 442.21 ± 3.40 kg average live body weight were randomly assigned to one of four dietary treatments according to a randomized complete block design. Cows were blocked according to their daily milk yield into three blocks of four animals each. Cows were fed a basal diet (control) or a basal diet supplemented with 1.25 kg/day dried Sesbania sesban leaves, 2 kg/day dried Sesbania sesban leaves and 2.75 kg/day dried Sesbania sesban leaves on a dry matter basis for 8 weeks. Total dry matter intake, nutrient intake, milk yield, dry matter digestibility, and nutrient digestibility showed significant variation among treatments. Cows supplemented with the highest level of Sesbania sesban (2.75 kg/day) had higher total dry matter and nutrient intake. Similarly, cows supplemented with 2 and 2.75 kg/day had higher milk yield than the nonsupplemented cows (up to 11.3 and 16.2%, respectively). Digestibility was lower for the nonsupplemented cows compared to cows supplemented with 2 and 2.75 kg/day dried Sesbania sesban leaves but statistically similar to the cows supplemented with 1.25 kg/day dried Sesbania sesban leaves. Supplementation with 2.75 kg/day Sesbania sesban resulted in higher organic matter digestibility (OMD) compared to the control. Crude protein digestibility (CPD), neutral detergent fiber digestibility (NDFD), and acid detergent fiber digestibility (ADFD) were significantly affected by Sesbania sesban supplementation. The nonsupplemented cows had lower CPD, NDFD, and ADFD. These results indicate that dried Sesbania sesban leaves supplementation to dairy increases total DM intake, digestibility, and milk yield. [ABSTRACT FROM AUTHOR]

In this work, an ecofriendly and economic strategy for synthesize of CuO and Co3O4 were developed using extracted Sesbania sesban solution (ESS) as a reducing and stabilizing agent, and bioreactor. These novel nano metal oxides (NMOs) were characterized by high-resolution-transmission electron microscopy (TEM), EDAX thermo gravimetric analysis and X-ray diffraction (XRD). Morphology and size of them were investigated by TEM and the average sizes of for spherical CuO and Co3O4 nanoparticles are 20-40 and 15-30 nm, respectively. The XRD and EDAX confirmed the high purity for NMOs. The thermal behaviors of the NMOs exhibited good crystallographic stability within the investigated temperature range. The antioxidant and antibacterial activities of NMOs were investigated and compared to manganese(III) meso-tetraphenylporphyrin complex/Ag nanocomposite (Ag/P nanocomposite) synthesizing by ESS. The results obtained from this work showed that copper(II) oxide, cobalt oxide nanoparticles, and Ag/P nanocomposite have DPPH scavenging activity. On the other hand, NMOs have no antibacterial activity against Gram-negative bacterial strains. Cobalt oxide nanoparticles have antibacterial activity against Staphylococcus aureus, while Ag/P nanocomposite showed the antibacterial activities against both Gram-negative and Gram-positive bacterial strains. [ABSTRACT FROM AUTHOR]

A pot experiment was carried out to assess Cd uptake and accumulation efficiency of Sesbania sesban. Plants were grown in soil spiked with 25, 50, 100, 150, 200, 250, and 300 mg/kg Cd. After 120 days, plants were harvested and analyzed for Cd content. A steady increase in Cd accumulation with increasing metal concentration in soil was observed for all treatments. Accumulation of Cd was greatest in roots (86.7 ± 6.3 mg/kg), followed by stem (18.59 ± 1.9 mg/kg), and leaf (3.16 ± 1.1 mg/kg). Chlorophyll content declined with increasing Cd concentration, while proline and protein content increased as compared to control. At higher Cd levels, root, shoot length, and biomass were all significantly reduced ( p ≤ 0.001). An increase in total protein along with greater A/A value suggested an increase in metal-protein complexes. Considering the rapid growth, high biomass, accumulation efficiency, and adaptive properties, this plant could be used as a valuable tool for the phytoremediation of Cd contaminated soils. [ABSTRACT FROM AUTHOR]

Sesbania sesban (L.) Merr is a perennial N-fixing tree with high potential for use in agricultural production systems as a green manure and livestock forage. We studied the interactive effects of soil type and water level on the growth, biomass allocation, nutrient and mineral content of S. sesban. Four-week old seedlings of S. sesban were grown for 49 days ( n = 5) in a factorial mesocosm set-up with six soil types (sediment, sand, alluvial, acid-sulfate, saline and clay) and three water levels (drained, water-saturated and flooded). The soils tested represent the predominant alluvial soil types of the Mekong delta, Vietnam. Sesbania sesban grew well with relative growth rates (RGR) around 0.08 g g d in all studied soil types, except the saline soil where plants died. In the low-pH (3.9) acid sulfate soil, that constitute more than 40 % of the Mekong delta, the RGR of the plants was slightly lower (0.07 g g d), foliar concentration of calcium was 3-6 times lower, and concentrations of iron and sodium up to five times higher, than in other soils. The nutrient and mineral contents of the plant tissues differed between the soils and were also affected by the flooding levels. Foliar concentrations of nitrogen (50-74 mg N g dry mass) and phosphorus (5-9 mg P g dry mass) were, however, generally high and only slightly affected by water level. The results show that S. sesban can grow well and with high growth rates on most wet soils in the Mekong delta, except saline soils where the high salt content prevents establishment and growth. The nutrient and mineral contents of the plants, and hence the nutritional value of the plants as e.g. fodder or compost crops, is high. However, soil type and water level interactively affect growth and tissue composition. Hence, optimal growth conditions for S. sesban differ in the different regions of the Mekong delta. [ABSTRACT FROM AUTHOR]

An experiment was conducted to assess the effect of substitution of concentrate mix with Sesbania sesban on feed intake, digestibility, average daily gain (ADG), and carcass parameters of Arsi-Bale sheep. The experiment employed 25 male sheep with mean (±standard error) initial body live weight (BLW) of 19.1 ± 0.09 kg. The experiment consisted of 7 days of digestibility and 90 days of feeding trials followed by carcass evaluation. The experiment employed a randomized complete block design with five treatments and five blocks. Treatments comprised of grass hay alone fed ad libitum (GHA; control), GHA + 100 % concentrate mix (CM) consisting of wheat bran and noug seed cake at a ratio of 2:1 (0 S. sesban), GHA + 67 % CM + 33 % S. sesban (33 S. sesban), GHA + 33 % CM + 67 % S. sesban (67 S. sesban), and GHA + 100 % S. sesban (100 S. sesban). Total dry matter intake (DMI) was higher ( p < 0.001) for sheep in 0 S. sesban–100 S. sesban (800–821 g/day) compared to sheep in control (611 g/day). However, the effect of S. sesban inclusion (0 S. sesban–100 S. sesban) on total DMI was quadratic, and DMI declined after 67 S. sesban. Digestibility of DM, organic matter ( p < 0.01), and crude protein were higher ( p < 0.001) in supplemented group compared to the control. ADG, feed conversion efficiency (ADG/DMI), slaughter BLW, hot carcass weight, and total edible offals were higher ( p < 0.05–0.001) for sheep in 0 S. sesban–100 S. sesban than those in control. Increased level of S. sesban inclusion, in general, reduced growth and carcass parameters in this study. However, there was no difference between 0 S. sesban and 33 S. sesban in most parameters studied. Thus, it can be concluded that S. sesban could substitute a concentrate when it accounted for up to 33 % of the mix. [ABSTRACT FROM AUTHOR]

Browse shrubs and trees, in spite of their significant role in livestock production in arid and semi-arid zones, are often omitted from pasture potential assessments because of the lack of methodology, the difficulty in calculation or method application and because it is usually a long and tedious task. For an accurate estimation of the carrying capacity of rangelands the shrub and tree fodder component has to be taken into account in order to avoid under estimation of the potential phytomass available for browsing. In this study, a semi-destructive method was used to develop fodder prediction equations of seven shrub and tree species based on multiple explanatory variables at four different locations in Burkina Faso (Taffogo, Safané, Nobéré, Dano and Sokouraba). The physical characteristics (explanatory variables) and the leaf weight (response variable) of the plants were measured or calculated and the non collinear explanatory variables correlated with the response variable. More than 50 % of the observed variation in fodder was explained by the basal area and/or the crown cover for all the target species except Ficus sur at Sokouraba and both Acacia seyal and Balanites aegyptiaca at Safané. The prediction equations were species-specific and equations developed for the same species in different sites were different. These results suggest that many local species-specific fodder prediction equations have to be developed to get an accurate fodder prediction in a large scale, and practitioners of rangelands management may be cautious about applying general species-specific prediction equation tables. [ABSTRACT FROM AUTHOR]

The success of agroforestry in semi-arid areas depends on efficient use of available water and effective strategies to limit tree/crop competition and maximise productivity. On hillsides, planting improved tree fallows on the degraded upper section of bench terraces is a recommended practice to improve soil fertility while cropping continues on the lower terrace to maintain food production. This study examined the influence of tree fallows on soil water content ( θ) and evaporation ( E). Alnus acuminata Kunth (alnus), Calliandra calothyrsus Meissner (calliandra), Sesbania sesban L. (sesbania), a mixture of all three species, or sole crops (beans ( Phaseolus vulgaris L.) or maize ( Zea mays L.)) were grown on the upper terrace. The same sole crops were grown on the lower terrace. Four management regimes (unpruned, root, shoot and root + shoot pruned) were applied to the tree rows adjacent to the cropping area. Neutron probe and microlysimeter approaches were used to determine θ and E when the trees were c. 3.5 years old. Sesbania and alnus increased θ by 9-18 % in the cropping area on the lower terrace but calliandra reduced θ by 3-15 %. After heavy rain, E comprised 29-38 % of precipitation in the tree-based treatments and 53 % under sole crops. Absolute values declined as rainfall decreased, but E as a proportion of rainfall increased to 39-45 % in the tree-based treatments and 62 % for sole crops. Root + shoot pruning of alnus and the tree mixture increased θ in the cropping area but had no significant effect in the other tree-based treatments. The results suggest that sesbania and alnus can be planted on smallholdings without compromising water supply to adjacent crops, whereas calliandra decreased water availability despite reducing E. These results provide a mechanistic understanding of reported effects on crop yield in the same site. [ABSTRACT FROM AUTHOR]

Fallowing can improve crop yields as a result of improved soil fertility and nutrient status. The objective of this work was to determine the effects of fallows and pruning regimes in coppicing fallows on soil moisture and maize yields under conventional tillage (CT) and no tillage (NT). Fallows that were evaluated were coppicing Acacia angustissima, non coppicing Sesbania sesban, natural fallow (NF) and continuous maize. In 2000/2001 season, maize yields were significantly different ( P < 0.05) among treatments and were; 1.8, 1.2, 0.7 and 0.5 tonnes per hectare (t ha) under CT, while under NT yields were 1.3, 0.8, 0.7 and 0.2 t ha for A. angustissima, maize, S. sesban and NF plots respectively. In 2001/2002 season, yields decreased in the order S. sesban > continuous maize > NF > A. angustissima, for both CT and NT. The 2-week pruning regime had significantly higher maize yields when compared to the 1 and 3 week pruning regime during the 2002/2003 cropping season. For the three seasons, CT had significantly higher yields than NT. A. angustissima had significantly higher mean available water at suctions <33 kPa for the 0-25 cm depth when compared to other fallow treatments. The bulk of the available water (47-80%) was retained at suction <33 kPa for all treatments and depths. There were no treatment differences in water retention at suctions >33 kPa for all treatments. It was concluded that improved fallowing increased yields when compared to NF. However, in coppicing fallows competition for water can result in reduced yields when there is rainfall deficiency, thus the need for pruning to manage the competition. [ABSTRACT FROM AUTHOR]

Agroforestry (AF) systems have been the focus of numerous research and development projects in southern Africa, yet their adoption rate generally remains low. Employing on-farm, participatory research techniques in southern Malawi, we compared the suitability of three AF-based systems that relay crop the dominant staple, maize ( Zea mays), with the perennial legumes Sesbania sesban, Tephrosia vogelii, and Cajanus cajan (pigeonpea). Our secondary objective was to compare two methodologies employed to investigate AF adoption: farming systems based ex ante adoption potential and ex post adoption analysis. Nineteen percent of farmers preferred S. sesban, 26% T. vogelii, and 55% pigeonpea. Between 2001 and 2003, S. sesban adoption ranged from 3 to 6%, T. vogelii from 16 to 20%, and pigeonpea from 76 to 100%. Pigeonpea and T. vogelii were primarily preferred and adopted for their immediate livelihood benefits—a secondary food source in the case of pigeonpea and a fish poison in the case of T. vogelii. Though S. sesban was the most promising in terms of biophysical impacts, many farmers found it labor intensive and its lack of immediate livelihood benefits was a deterrent to adoption. With food insecurity a pervasive hardship in the region, farmers will likely continue to focus on satisfying immediate livelihood needs before prioritizing longer-term soil-quality improvement techniques. Both ex ante adoption potential and ex post adoption analysis contributed distinct and valuable data, and relying on either exclusively would have limited our understanding of the AF systems. [ABSTRACT FROM AUTHOR]

Integration of trees on farms may exert complementary or competitive effects on crop yield. This 4 year study examined novel systems in which Alnus acuminata (alnus), Calliandra calothyrsus (calliandra), Sesbania sesban (sesbania) or a mixture of all three were grown on the degraded upper part of bench terraces in Uganda; beans or maize were grown on the more fertile lower terrace during the short and long rains. Three pruning treatments (shoot, root or shoot + root pruning) were applied to the tree rows adjacent to the crops; shoot prunings were applied as green manure to the woodlot from which they came. Pruning increased survival in calliandra and reduced survival in sesbania; alnus was unaffected. Pruning reduced tree height and stem diameter in alnus, but did not affect calliandra or sesbania. Maize yield adjacent to unpruned calliandra, alnus and sesbania or a mixture of all three was reduced by 48, 17, 6 and 24% relative to sole maize. Shoot pruning initially sustained crop performance but shoot + root pruning became necessary when tree age exceeded 2 years; shoot + root pruning increased maize yield by 88, 40, 11 and 31% in the calliandra, alnus, sesbania and tree mixture systems relative to unpruned trees. Bean yield adjacent to unpruned calliandra, alnus, sesbania and the tree mixture was 44, 31, 33 and 22% lower than in sole crops and pruning had no significant effect on crop yield. The results suggest that sesbania fallows may be used on the upper terrace without reducing crop yield on the lower terrace, whereas pruning of alnus is needed to sustain yield. Calliandra woodlots appear to be unsuitable as crop yield was reduced even after pruning. [ABSTRACT FROM AUTHOR]

In the north Ethiopian highlands, gully erosion is a significant land degradation process. Although the protective role of vegetation has been demonstrated in many studies, efforts previously made in using woody species for erosion control in the research area are limited, and when applied, survival of the planted seedlings was very low. Lack of experience and fundamental knowledge on species autecology and traits are two important bottlenecks. This study therefore aims at better understanding seedling establishment and growth in a context of tree plantings, with the view to further control gully erosion in a semi-arid environment. To this end survival, growth and development of seedlings of Acacia etbaica Schweinf., Sesbania sesban (L.) Merr. and Dodonaea angustifolia L.f. were monitored during 26 months in a field trial under different site conditions and treatments. The experiment was established at two sites characterized by topographic and edaphic conditions (Vertisol and sandy colluvium) representative for the study area. At each site, seedlings were subjected to different treatments of watering, sheltering and planting position (gully floor, sidewall and shoulder), and a large set of plant growth variables was regularly monitored. Height and biomass growth was fastest for Sesbania, even if affected by different pests. Regardless of the species, plants growing in the (nutrient-rich) Vertisol site had a higher survival rate and an overall better development. Shelter protection significantly increased survival and resulted in taller seedlings. Notwithstanding these general trends, treatment effects were often varying over time and strongly influenced by specific edaphic conditions. Generally, Acacia performed best on gully shoulder and wall, Sesbania on the gully floor and Dodonaea on shoulder positions. Recommendations for planting practice and follow-up research are discussed. [ABSTRACT FROM AUTHOR]

The effects of different inorganic fertilizers (Urea and Triple Super Phosphate (TSP)) on seedling growth and nodulation capabilities of four agroforestry tree species ( Albizia chinensis, A. saman, Acacia nilotica and Sesbania sesban) were compared. The nodulation of these seedlings were treated with different fertilizer treatments (at the rate of urea 40 kg·hm−2, urea 80 kg·hm−2, TSP 40 kg·hm−2, TSP 80 kg·hm−2, (urea+TSP) 40 kg·hm−2–and (urea+TSP) 80 kg·hm−2) after one month of seed germination. The results revealed that the seedling growth was enhanced significantly with moderate fertilizer treatment. In some cases, the higher levels of fertilizers reduced the seedling growth. The study also revealed that the nodulation in nodule number and size was significantly inhibited by the application of N fertilizer (Urea), while it was increased significantly with the application of P fertilizer (TSP). This study improved our understanding and provided insights that would be useful to the farmers in their efforts to amend the soil with inorganic fertilizers in order to enhance plant growth and biological nitrogen fixation. [ABSTRACT FROM AUTHOR]

Improved fallows have been used to reduce time required for soil fertility regeneration after cropping in low input agricultural systems. In semi-arid areas of Southern Africa, Acacia angustissima and Sesbania sesban are among some of the more widely used improved fallow species. However the residual effects of improved fallows on soil hydraulic properties during the cropping phase is not known. The aim of this study was to quantify the residual effects of fallows and tillage imposed at fallow termination on soil hydraulic properties (infiltration rates, hydraulic conductivity and soil porosity) during the cropping phase. Treatments evaluated were planted fallows of Acacia angustissima, Sesbania sesban and natural fallow (NF) and continuous maize as a control. Steady state infiltration rates were measured using a double ring infiltrometer and porosity was calculated as the difference between saturated infiltration rates and tension infiltration measurements on an initially saturated soil. Unsaturated hydraulic conductivity (Ko) and mean pore sizes of water conducting pores were measured using tension infiltrometer at tensions of 5 and 10 cm of water on an initially dry soil. While there was no significant difference in steady state infiltration rates from double ring infiltrometer measurements among the fallow treatments, these were significantly higher than the control. The steady state infiltration rates were 36, 67, 59 and 68 mm h-1 for continuous maize, A. angustissima, S. sesban and NF respectively. Tillage had no significant effect on steady state infiltration rate. Pore density at 5 cm tension was significantly higher in the three fallows than in maize and varied from 285-443 m-2 in fallows, while in continuous maize the pore density was less than 256 m-2. [ABSTRACT FROM AUTHOR]

Sesbania sesban (L.) Merr. (sesbania) is a fast growing N2-fixing widely used as an improved fallow species by smallholder farmers in eastern and southern Africa to restore fertility of their N-deficient soils. In order to establish the need for inoculation, the population of sesbania rhizobia in soil collected from a site where the species is intended for introduction was assessed using the most probable number (MPN) plant infection assay. The MPN of sesbania rhizobia was low (21, 6-81 fiducial limits at P=0.05 g-1soil) but with N2-fixation potential comparable to sesbania inoculant strain KFR 651. Evaluation of an indigenous sesbania rhizobial isolate GSS 1 from the MPN assay in potted field soil showed that it was more effective than strain KFR 651 in terms of plant growth and shoot dry matter (DM) accumulation at 9 and 12 weeks after planting, respectively. Total shoot N content was also higher for plants inoculated with isolate GSS 1 than inoculant strain KFR 651 and uninoculated control treatments 12 weeks after planting. These results demonstrate that it is better to inoculate with effective indigenous than exogenous rhizobia where the need for inoculation has been established. [ABSTRACT FROM AUTHOR]

The coverage of trees in the highland Vertisol areas of Ethiopia is very scarce. A tree screening trial was conducted from 1997 to 2002 in Ginchi (central Ethiopia) to select fast growing and high biomass producing tree species; evaluate foliage macronutrient concentration of different tree species; and assess effects of trees on soil chemical properties beneath their canopies. Acacia decurrens Willd, A. mearnsii De Wild and Eucalyptus globulus Labill attained the highest height growth at 64 months as compared to other indigenous and exotic species. E. globulus provided better height increment from 24 to 36 and 36 to 64 months than other tree and shrub species. Acacia mearnssi and A. saligna Labill Wendl produced high biomass at 40 and 64 months. Differences between the highest and lowest dry biomass at 12, 40 and 64 months were 1.13, 29.19 and 38.89 kg tree)1, respectively. None of the tree species resulted in a foliage to stem biomass ratio of >0.98 at 40 and 64 months. Sesbania sesban (L.) Merr had high N and P concentrations in its foliages and stems at 12 and 40 months. Total N under Acacia abyssinica Hochst. Ex Benth, A. saligna and S. sesban was slightly greater at 40 months than 12 months. [ABSTRACT FROM AUTHOR]

Abstract A field experiment was performed in eastern Kenya to estimate N2 fixation by Sesbania sesban over an 18-month period using the 15N dilution method. The influence of three reference species, Senna spectabilis, Eucalyptus saligna and Grevillea robusta, on the estimates of N2 fixation was also assessed. Percentage Ndfa (nitrogen derived from the atmosphere) was calculated based on foliar atom excess (FAE), above-ground atom excess (AAE) or whole tree atom excess (WAE) data. The differences in atom% 15N excess values between species and plant parts are presented and discussed. We recommend the use of several reference species for estimating %Ndfa and that the different results obtained should be carefully considered in relation to the issues being addressed. In this study, Senna was the most suitable of the three reference species because its N uptake pattern and phenology were very similar to those of Sesbania. When well established, the amount of N fixed by Sesbania accounts for more than 80% of its total N content, according to FAE-based estimates. We estimated the Ndfa by Sesbania after 18 months to between 500 and 600 kg ha-1 , depending on whether FAE, AAE or WAE data were used and on the choice of reference species. The substantial accumulation of N in planted Sesbania highlighted its potential to increase the sustainability of crop production on N-limited soils. We consider the 15N dilution method to be appropriate for quantifying N2 fixation in improved fallows in studies, similar to this one, of young trees with high N2-fixing ability. [ABSTRACT FROM AUTHOR]

Three woody legumes were planted as two-year `improved fallows' to evaluate their residual nitrogen (N) effects on two subsequent maize crops under minimum and conventional tillage management. Maize monoculture and cowpea-maize-maize sequence treatments were included as controls. N2-fixation was estimated using the 15N natural abundance method to allow the N contribution from the fallows to be partitioned into N2-fixation and soil N capture. Acacia angustissima accumulated the largest amount of both below-ground and above-ground biomass during the 2-year growth period. Using Hyparrhenia grass as the reference plant, the proportion of N2-fixed in litter was 56, 55, 84 and 58% for Acacia, Sesbania sesban, Cajanus cajan, and cowpea, respectively, resulting in inputs of biologically fixed N of 122, 84, 96 and 28 kg N ha-1. Maize growth following the legumes for two subsequent cropping seasons was in most cases not directly related to the N inputs. The first year maize crop was severely infested with cutworms (Agrotis sp.) in the Sesbania and Acacia plots, while the second season maize was affected by drought particularly in the Acacia plots where there was high moisture demand by the re-growing trees. During the second season, N uptake by maize following Sesbania was significantly higher than the rest of the treatments. Conventional tillage resulted in better yields than minimum tillage across all treatments and in both seasons. It can be concluded that (1) improved legume fallow system results in net positive soil N balances, (2) despite large inputs of litter and continued recycling of N during the cropping phase, legume species that re-grow after cutting can result in depressed yields in drought seasons, and (3) tillage is beneficial even after improved legume fallows. [ABSTRACT FROM AUTHOR]

The sesbania beetle, Mesoplatys ochroptera Stål (Chrysomelidae: Coleoptera), is a serious defoliator of Sesbania sesban in eastern and southern Africa. Developing integrated pest management practices against the beetle is an important aspect of the adoption of S. sesban as an improved fallow species. Field studies were conducted in eastern Zambia with the objective of determining the incidence of M. ochroptera on S. sesban in pure and mixed species fallows. M. ochroptera did not successfully feed or breed on species other than S. sesban either in the pure or mixed species fallows. The density of adult and immature stages of M. ochroptera was higher in mixtures of S. sesban with Mucuna pruriens, Macrotyloma axillare, Macroptilium atropurpureum or Crotalaria grahamiana compared to a pure S. sesban fallow. Although mixed fallows of S. sesban with M. axillare and M. pruriens may produce fodder, increase the amount and quality of organic inputs and improve nutrient cycling in the soil, they appear to be incompatible with management of M. ochroptera. Mixing S. sesban with G. sepium neither increased larval and adult populations of M. ochroptera feeding on S. sesban nor damage to it. While this mixture appeared to favour development of pupae to the adult stage, it increased mortality of emerging adults. Therefore, it is concluded that mixing S. sesban with G. sepium is more robust in nutrient cycling, improving resource utilisation and management of M. ochroptera on S. sesban. [ABSTRACT FROM AUTHOR]

Developing integrated pest management practices against the defoliating beetle Mesoplatys ochroptera is an important aspect of the adoption of Sesbania sesban as an improved fallow species in southern Africa. The effect of defoliation by M. ochroptera on the growth of S. sesban (provenance Kakamega) was studied during 1998–2000 at Msekera Research Station in eastern Zambia. To determine the relationship between M. ochroptera densities and degree of defoliation, potted seedlings were infested manually with different densities of larvae and adults. Infestation of two to three month old seedlings with 5–30 larvae or adults resulted in less than 20% defoliation. Infestation of seedlings with 90–150 larvae (>3 masses of eggs) led to 80–100% and 50–80% defoliation in two and three months old seedlings, respectively. The time of infestation and degree of defoliation that lead to reduction in growth and biomass were determined using simulated (manual) defoliation of one to three months old S. sesban seedlings. Manual removal of 50–100% of the foliage at one and two months after transplanting (MAP) appeared to reduce plant height, basal diameter, primary branches, leaf and wood biomass compared to that done at three MAP. Removal of 25–50% of the sesbania foliage three months after transplanting apparently leads to overcompensation. In sesbania, compensatory growth occurred when 25–50% of the leaves were defoliated three months after transplanting. Therefore, farmers need to protect sesbania seedlings from defoliation against insects such as M. ochroptera only during the first two months after transplanting. [ABSTRACT FROM AUTHOR]

Examines the effects of planted fallows of Sesbania sesban and Calliandra calothyrsus on soil inorganic nitrogen dynamics and subsequent maize crops in Kenya. Determination of ground biomass and nitrogen content; Soil organic matter; Effect of tree fallows on subsequent maize crops.

Examines the seedling inoculation test for Sesbania sesban and other Sesbania species in Kenya. Susceptibility of S. sesban to Mesoplatys ochroptera; Resistance of S. cinerascens to M. ochroptera; Measurement on the leaf consumption and larvae abundance of M. ochroptera.

Mesoplatys ochroptera Stål (Coleoptera: Chrysomelidae) is a serious pest of the tropical legume sesbania ( Sesbania sesban (L.) Merrill) widely used for soil fertility improvement in southern Africa. Surveys were conducted between October 1997 and June 1999 in order to identify the predators of M. ochroptera in sesbania fallows in eastern Zambia. The Heteroptera Afrius yolofa (Guérin-Méneville), Glypsus conspicuus (Westwood), Macrorhaphis acuta Dallas, Mecosoma mensor (Germar), Rhinocoris segmentarius (Germar), and Deraeocoris ostentans (Stål), the carabid beetle Cyaneodinodes fasciger (Chaudoir), the ants Tetramorium sericeiventre Emery and Pheidole sp., and the lacewing Mallada sp. were recorded as predators of M. ochroptera for the first time. The pentatomid bugs G. conspicuus, M. acuta and M. mensor were the most common predators in sesbania fallows. Adults and the different nymphal stages of the three species preyed on larvae, adults and occasionally on eggs of the beetle. In the insectary, the adults of G. conspicuus, M. acuta and M. mensor consumed a significantly higher number of larvae ( p < 0.001) compared to adults of M. ochroptera under both free-choice and no-choice conditions. The voracity of the three species showed a positive response to prey density. The fifth instar nymphs showed variation in daily consumption of larvae, the highest number of prey being consumed two to three days after the fourth molt. These predators also attacked other pests associated with sesbania and crop plants. The potential role of the predators in the natural control of pests in agroforestry systems is discussed, with a review of their prey species. [ABSTRACT FROM AUTHOR]

In eastern Zambia, nitrogen deficiency is a major limiting factor for increased food production. Soil fertility has been declining because of nearly continuous maize (Zea mays) cultivation with little or no nutrient inputs. The use of short-duration tree fallows was one of several agroforestry options hypothesized to restore soil fertility. Sesbania sesban, an indigenous N/math>-fixing tree was the most promising among species tested in screening trials. Several studies since 1987 have demonstrated the dramatic potential of two- or three-year sesbania fallows in restoring soil fertility and increasing maize yields. Analyses showed that these improved fallow systems were feasible, profitable, and acceptable to farmers. Results suggest that high maize yields following fallows are primarily due to improved N input and availability by the fallows. The potential to increase maize production without applying mineral fertilizers has excited thousands of farmers who are enthusiastically participating in the evaluation of this technology. The number of farmers who are testing a range of improved fallow practices has increased from 200 in 1994 to over 3000 in 1997. Presently, a strong network of institutions comprising government, NGOs, development projects, and farmer organizations is facilitating the adaptive research and expansion of improved fallow technology in eastern Zambia. Key elements in the research process that contributed to the achievements are effective diagnosis of farmers' problems, building on farmers' indigenous knowledge, generating several different fallow options for farmers to test, ex-ante economic analysis, farmer participation in on-farm trials, and development of a network for adaptive research and dissemination. [ABSTRACT FROM AUTHOR]

The relay cropping of sesbania (Sesbania sesban) -- a N/math>-fixing legume -- with maize (Zea mays) has been proposed as a strategy to increase soil fertility and food production in densely populated areas in southern Africa. We determined the production of relay-cropped maize and sesbania at three landscape positions under researcher-designed and farmer-managed conditions in southern Malawi. Three landscape positions (dambo valley or bottomland, dambo margin with < 12% slope, and steep slopes with > 12% slope) were examined in factorial combination with N sources for maize (no added N, relay-cropped sesbania, and calcium ammonium nitrate fertilizer). Relay cropping of sesbania with maize increased maize grain yield, as compared to unfertilized sole maize in two of three years. Split application of 96 kg N ha^−1 as N fertilizer, however, was more effective than sesbania in increasing maize yields. Survival of sesbania seedlings and biomass production of sesbania were greater in the dambo valley and dambo margin than on steep slopes. Maize yields tended to be lower on steep slopes than in the dambo valley and dambo margin areas. Biomass production of sesbania and hence the potential benefits of intercropping sesbania with maize appear greater in the dambo valleys and dambo margins than on steep slopes. [ABSTRACT FROM AUTHOR]

Sesbania (Sesbania sesban), which is promoted as a short- duration-fallow species in eastern and southern Africa, is an alternative host to root-knot nematode (Meloidogyne spp.). Therefore, it is important to know the extent of sesbania infection by the nematode on farms and its effects to crops grown in rotation with sesbania. A survey of 14 farms in western Kenya indicated that sesbania was infected by root-knot nematode in all the farms. The potential to build up the nematode population was much greater on farms where maize (Zea mays) was previously intercropped with a susceptible bean (Phaseolus vulgaris). Screening of 30 single plant accessions of four sesbania provenances (Kakamega, Siaya, Kisumu, and Kisii) from western Kenya in pots indicated limited scope for selecting material resistant to the nematode. All four provenances were infested by the nematode, and they increased its population in soil and root. A rangewide collection of sesbania germplasm needs to be screened to determine the scope of finding nematode-resistant material. Transplanted seedlings produced in heat-sterilized, nematode-free soil showed less nematode infection than direct-seeded plants. However, both direct seeding and transplanting seemed to increase nematode population similarly. A number of Crotalaria spp. that were found resistant to nematodes can be considered as alternatives to sesbania-planted fallows, but further field-scale testing is necessary to select appropriate species based on biomass production. Among other species suitable for short-duration fallows, only pigeonpea (Cajanus cajan) and senna (Senna siamea) showed promise. Species such as neem (Azadirachta indica), casuarina (Casuarina junghuhniana), and grevillea (Grevillea robusta) that are suitable for boundary plantings were free from the root-knot nematode. [ABSTRACT FROM AUTHOR]

Simple methods for the measurement of nitrogen (N) availability are needed to assess the effect of low-input, organically based land management systems on the N supply of tropical soils. Our objectives were to determine the effect of contrasting land-use systems (LUS) on soil N availability and to identify measures of N availability that correlated with maize ( Zea mays L.) grain yield. The LUS at the two sites in Kenya involved growth of a maize crop following 17 months of either: (1) Sesbania sesban (L.) Merr. tree growth (sesbania fallow), (2) natural regrowth of vegetation without cultivation (natural fallow), (3) three crops of unfertilized maize (maize monoculture), or (4) bare uncultivated soil (bare fallow). Soil was collected before the post-fallow maize crop was sown. The LUS had no effect on total soil N or amount of N in the heavy fraction soil organic matter (SOM) (>150 μm, >1.37 Mg m–3). Sesbania and natural fallows, as compared to maize monoculture, increased the N in light fraction SOM (>150 μm, <1.13Mgm–3), N in intermediate fraction SOM (>150 μm, 1.13 to 1.37 Mg m–3), ammonium-N and aerobic N mineralization at a depth of 0–15 cm. Maize yields were highest following the sesbania fallow. Nitrate-N, inorganic-N (ammonium plus nitrate) and anaerobic N mineralization correlated with maize grain yield at both sites. The relationship between maize yield and pre-season nitrate-N improved when the depth of soil sampling was increased to 1 m at one site (an Alfisol), but did not improve at the site with anion adsorption in the subsoil (an Oxisol). The sesbania fallow was more effective than the natural fallow in increasing available soil N. Maize yield was better related to pre-season nitrate than N in size-density fractions of SOM. [ABSTRACT FROM AUTHOR]

Alley cropping with leguminous tree hedgerows planted on contours is an emerging practice in the northern highlands of Rwanda where field slopes range from 4 to 76% and loss of soil fertility due to erosion is the principal impediment to food production. Sesbania sesban and Leucaena Leucocephala, the two woody species recommended for alley cropping in the region, do not perform equally well across sites: Sesbania is faster growing, But is more sensitive to pruning than Leucaena. We tested the hypothesis that the two species could be grown together to make the best use of their relative advantages. Species were planted in pure and 1:1 mixed stands at 26 sites to give a range of altitudes, slopes, azimuths and soil fertility levels representative of the region. During two cropping seasons'' growth spanning 19 months, in pure stands, Sesbania produced more biomass, grew taller and had thicker stems than Leucaena: for the same species, stem diameter and height were not different in pure and mixed stands. Biomass and number of poles from 1:1 mixed stands of Sesbania and Leucaena were equivalent to biomass and pole numbers from Sesbania in pure stands. However, mixed stands produced more biomass and pole numbers than Leucaena in pure stands. Growth of S. sesban was positively correlated with soil pH, potassium and altitude; whereas, growth of L. leucocephala was positively correlated with soil phosphorus, but negatively correlated with field slope. All other soil and site variables tested were nonsignificant. The study suggests that farmers can plant S. sesban and L. leucocephala in 1:1 mixtures in an alley cropping setting and retain levels of biomass production and bean pole numbers equivalent to those from S. sesban alone without compromising future growth and production by Leucaena. As well, the impact of pH, K and P on growth and production of Sesbania and Leucaena as a function of field slope and altitude should be determined before extending their use to other regions. [ABSTRACT FROM AUTHOR]

Investigations were carried out using the vesicular arbuscular mycorrhizal fungus, Glomus fasciculatum, to improve the success in transplanting micropropagated plantlets of Sesbania sesban. Plantlets were developed from somatic embryos and/or adventitious buds (induced from various explants on Gamborg's medium supplemented with 6-benzylaminopurine), in the presence of 10–7 m α-naphthaleneacetic acid and 5×10–6 m gibberellic acid. Subsequent to nodulating the roots with Rhizobium, plantlets were transplanted into sterile garden soil and inoculated with or without G. fasciculatum. Only 30% of plantlets transferred to soil without G. fasciculatum survived. In contrast, all the plantlets inoculated with G. fasciculatum survived. Histochemical study revealed the presence of intracellular hyphae with well-developed arbuscules and intercellular hyphae with vesicles, suggesting that G. fasciculatum formed a good mycorrhizal association with S. sesban roots. These observations showed that mycorrhizal association helped to increase the potential of micropropagated plantlets to successfully withstand transplantation shock. [ABSTRACT FROM AUTHOR]

Nitrogen deficiency is widespread in southern Africa, but inorganic fertilizers are often unaffordable for smallholder farmers. Short-duration leguminous fallows are one possible means of soil fertility restoration. We monitored preseason topsoil (0 to 20 cm) ammonium and nitrate, fallow biomass production and grain yields for three years in a relay cropping trial with sesbania [Sesbania sesban (L.) Merr.] andmaize (Zea mays L.). Sesbania seedlings were interplanted with maizeduring maize sowing at 0, 7400 or 14,800 trees ha-1, in factorial combination with inorganic N fertilizer at 0 or 48 kg N ha-1 (half the recommended rate). After maize harvest, fallowswere allowed to grow during the seven-month dry season, and were cleared before sowing the next maize crop. Both sesbania fallows and inorganic N fertilizer resulted in significantly greater (P < 0.01 to 0.05) preseason topsoil nitrate-N than following unfertilized sole maize. In plots receiving no fertilizer N, preseason topsoil inorganic N correlated with maize yield over all three seasons (r2 = 0.62, P < 0.001). Sesbania fallows gave significantly higher maize yields than unfertilized sole maize in two of three years (P < 0.01 to 0.05). Sesbania biomass yields were extremely variable, were not significantly related to sesbania planting density, and were inconsistently related to soil N fractions and maize yields. Short-duration fallows may offer modest yield increases under conditions where longer duration fallows are not possible. This gain must be considered against the loss of pigeonpea (Cajanus cajan L. Millsp) harvest in the similarly structured maize-pigeonpea intercrop common in the region. [ABSTRACT FROM AUTHOR]

This study was based at the Agroforestry Research Centre, Maseno Kenya. The objective was to evaluate the effects of pre-treatment, seed rate and depth of sowing seed on direct seeding of Sesbania sesban. Direct seeding was shown to be feasible during the rainy season, provided a shallow seed bed was used. Direct seeding at 3 cm furrow depth led to significantly (P = 0.05) greater germination compared to 10 cmdepth. There was no effect of pretreatment and seed rate on germination, early seedling growth and dry matter partitioning. Depth of sowing similarly had no effect on early growth and dry matter partitioning. Establishment by direct seeding is relatively non-labour intensivewith a probable high adoption potential. [ABSTRACT FROM AUTHOR]

Measurements of root and nutrient distributions in agroforestry systems have often been obtained from unreplicated plots. We, therefore,measured the vertical and horizontal distribution of root length andsoil nitrate in replicated plots of sesbania [Sesbania sesban (L.) Merr.] to assess plot-to-plot variation and identify appropriate sampling schemes. Sampling was on profile walls exposed from pits at two on-farm sites (Ochinga and Muange) in Kenya. At Ochinga, soil was sampled at 27 0.15-m depth intervals and eight 0.15 -m-wide locations perpendicular to 2.25-m-wide rows of 19-month-old sesbania. At Muange, sampling was 18 months after establishment of sesbania from seedlings with a 1 m by 1 m spacing. Soil was sampled at 17 0.15-m depth intervals and nine 0.15-m-wide sampling locations - one exactly below the tree and four each on opposite sides of the tree. Root length density generally decreased with distance from sesbania and with soil depth. Soil nitrate, however, followed different trends in the four replications at Ochinga and the three replications at Muange. At Ochinga, nitrate above 2.5-m depth clearly increased with distance from thetree in two replications but followed no distinct trend in another replication. At Muange, nitrate above 1.2-m depth decreased with distance from the tree in one replication, increased with distance from the tree in another replication and followed no clear trend in anotherreplication. The suitability of various sampling schemes for measuring root length and nitrate was accessed from percent bias between measured values at sampling locations in the scheme and actual values for an entire transect of sampling locations. Bias associated with selection of sampling locations tended to be higher within the 2.25-m-wide sesbania rows than the 1 m by 1 m sesbania spacing. Soil samplingin systems with rows of young trees should be at several locations along a transect perpendicular to tree rows in order to minimize bias. [ABSTRACT FROM AUTHOR]