Calliandra Calothyrsus Research Articles

Digestibility of some tropical browse species varying in tannin content

The nylon bag dry matter digestibility (NBDMD) of one grass and 12 tropical shrubs (10 legumes and two non-legumes) varying in tannin content was measured in the rumens of five Droughtmaster steers. Five terminal and fully expanded leaves of each shrub were harvested by hand plucking, chopped fresh to about 3 mm lengths and incubated (either as fresh or after oven-drying at 65°C for 24 h) for 48 h. Chemical contents of freeze-dried samples varied widely among species: 1.59–3.84% for N, 25.93–53.21% for NDF, 19.17–39.44% for ADF and 1.97–19.36% for ADL. Extractable condensed tannin levels ranged from 0.3 to 11.6% for vanillin/HCl and from 0 to 9.3% for butanol/HCl extraction. Bound tannins also varied, the protein bound component of both Gliricidia sepium and Bauhinia rufescens exceeding 2% of the dry matter. B. rufescens also had a high fibre-bound tannin level of 0.9%. Oven drying consistently increased the NDF values and also increased the ADF and ADL levels in all species except Calliandra calothyrsus where there was a slight depression. However, the effect of oven drying on digestibility with this species was dramatic – 78% for fresh versus 41% for dried. For most of the other species NBDMD was similar for fresh and dried samples. NBDMD differed among species ( p<0.001) from 18 to 78% for dried material and from 20 to 78% for fresh material. It was generally low in high tannin species and vice versa except for Calliandra calothyrsus which had high NBDMD for fresh material and high tannin, and Acacia currasavica which had low NBDMD but only average tannin levels. Only 5 of the 10 leguminous browse species evaluated were considered to be useful in sown pastures on the basis of their digestibility these were Leucaena leucocephala, Gliricidia sepium, Albizia lebbek, Albizia richardiana and Calliandra calothyrsus. The non-leguminous, non-tanniniferous Combretum erythrophloeum had the highest NBDMD of all the browse species tested. Significant correlations existed between NBDMD and NDF, ADF, ADL and extractable tannins but not with the bound tannins.

Phosphate rock dissolution and transformation in the rhizosphere of tea (Camellia sinensis L.) compared with other plant species

SummaryTea (Camellia sinensis L.) is generally grown in highly weathered acidic Ultisols of the humid tropics. The low pH, large P fixing capacity and moisture content of these soils favour the dissolution of phosphate rock. Plant species differ widely in their ability to take up P from phosphate rock, and we have compared phosphate mobilization in the rhizosphere of tea with that under calliandra (Calliandra calothyrsus L.), Guinea grass (Panicum maximum L.) and bean (Phaseolus vulgaris L.) by studying the changes in the concentration of P fractions at known distances from the root surface in an acidic (pH in water 4.5) Ultisol from Sri Lanka treated with a phosphate rock. Plants were grown in the top compartment of a two‐compartment device, comprising two PVC cylinders physically separated by a 24‐μm pore‐diameter polyester mesh. A planar mat of roots was formed on the mesh in the top compartment, and the soil on the other side of the mesh in the lower compartment was cut into thin slices parallel to the rhizosphere and analysed for pH and P fractions.All plant species acidified the rhizosphere (pH [water] difference between bulk and rhizosphere soils was 0.17‐0.26) and caused more rock to dissolve in the rhizosphere (10–18%) than in the bulk soil (8–11%). Guinea grass was most effective, though the rate of acidification per unit root surface area was least (0.02μmol H+ cm−2) among the four species. Tea produced the largest rate of acidification per unit root surface area (0.08μmol H+ cm+2). All species depleted P extracted by a cation–anion exchange resin and inorganic P extracted by 0.1 M NaOH. All except tea depleted organic P extracted by 0.1M NaOH in the rhizosphere. The external P efficiencies (mg total P uptake) of Guinea grass, bean, tea and calliandra in soil fertilized with phosphate rock were 4.82 ± 0.42, 4.02 ± 0.32, 1.06 ± 0.02 and 0.62 ± 0.02, respectively, and the corresponding internal P efficiencies (mg shoot dry matter production per mg plant P) were 960 ± 75, 1623 ± 79, 826 ± 33 and 861 ± 44. This study showed that the various crops cultivated in tea lands differ in their rates of acidification, phosphate rock dissolution and P transformation in the rhizosphere. This requires testing under field conditions.

N recovery from legume prunings and priming effects are governed by the residue quality

Nitrogen recovery from 15 N-labelled prunings of Gliricidia sepium, Peltophorum dasyrrachis, Calliandra calothyrsus and Leucaena leucocephala,each of two different chemical qualities, was followed over three cropping cycles in a growth room. Half of the pots of each treatment received a further addition of unlabelled pruning material, from the same species as that previously applied, before the second and third crop cycle. The cumulative maize total N accumulation revealed the largest benefit from N rich, low lignin and polyphenols Gliricidia prunings followed by Leucaena, Calliandra and Peltophorum. Cumulative N recovery measured using 15 N over the three crop cycles ranged from 9% from Calliandra prunings to 44% from Gliricidia prunings. The vast majority of this N was recovered during the first crop cycle which agreed well with estimates using the N difference method. Recoveries in the second and third crops ranged from 0.4‐5% ( 15 N method) and 6‐14% (N difference method) of the N initially applied. The protein binding capacity of polyphenols was the best predictor of N recovery at both initial and later crop cycles. Treatments which led to a large N recovery initially, continued to provide greater N benefits in subsequent cycles although with increasing harvest time this trend decreased. Thus, there was no compensation in initial N release from low quality prunings at later harvests and the agronomic implications of this are discussed. Addition of unlabelled Gliricidia prunings before the second and third cycle led to a positive apparent priming effect on previously applied 15 N labelled prunings. By contrast, repeated additions of Peltophorumresidues, rich in lignin and active polyphenols, resulted in a reduced recovery of initially applied pruning- 15 N. However, the maximum positive or negative effects on recovery of pruning N amounted to less than 2% recovery of the initial amount of N added over 14 weeks. Thus the scope for regulation of N release from tree prunings during these later stages of decomposition appears to be limited.

Shrubby legumes for fallow improvement in northern Laos: establishment, fallow biomass, weeds, rice yield, and soil properties

An experiment was carried out in a slash-and-burn production system in northern Laos to evaluate legume establishment methods and effects of legume species on fallow vegetation, weeds, yield of upland rice, and soil parameters. Cajanus cajan, Calliandra calothyrsus, Crotalaria anagyroides, Flemingia congesta, Leucaena leucocephala, and Sesbania sesban were dibbled separately or mixed with rice. Legume and planting method had no effect on rice yield. Legume establishment was slightly improved and vigor after rice harvest was higher when planted in separate hills. Compared to control (no legume), the above ground fallow biomass observed 13 months after establishment, consisting mostly of Chromolaena odorata, was reduced by 68% with C. anagyroides and by 40% with L. leucocephala, while other species had no effect. Most of the C. cajan and S. sesban plants died. In March 1995, 22 months after planting, the biomass was 0.21, 0.25, 1.62 and 2.56 kg m-2 for F. congesta, C. calothyrsus, C. anagyroides, and L. leucocephala, respectively. Legume species had no effect on rice yield or weed biomass in the rice crop. The species tested can influence fallow vegetation but do not allow for field preparation without burning. Compared to mulching, burning of residue reduced weed biomass by 42%, soil organic C by 9% and the C/N ratio by 6% but increased extractable P by 90% and pH by 8%.

COMPARATIVE PERFORMANCE OFLEUCAENA PALLIDAANDCALLIANDRA CALOTHYRSUSON AN ACID SOIL IN A SUB-HUMID ENVIRONMENT IN BURUNDI

SUMMARY The influence at the first cutting on the growth and yield of Leucaena pallida and Calliandra calothyrsus was studied on an acid soil with high Al saturation in the mid-altitude highlands of Burundi. During the first 15 mo after planting, average leaf and wood yield of L. pallida were 1.2 and 1.1 t ha-1, respectively, whereas those of C. calothyrsus were 5.0 and 4.5 t ha-1, respectively. In the second year, average leaf yield of L. pallida was 24% of that of C. calothyrsus. The age at which L. pallida was cut back for the first time—3, 6, 9, 12 or 15 mo after planting—did not influence total leaf yield during the first 15 mo nor that of the subsequent nine mo of growth. Total leaf yield of C. calothyrsus was highest when the trees were cut back nine mo after planting. Relative to Calliandra, L. pallida showed relatively low productivity on the Al-toxic highland soil, and therefore it is not recommended for fodder or wood production in this environment.

Vertical Distribution of Roots and Soil Nitrate: Tree Species and Phosphorus Effects

AbstractWe hypothesized that trees can rapidly root into subsoil and capture NO3, which can accumulate in the subsoil of agricultural soils with high anion sorption. The vertical distribution of root length and inorganic N (NO3 and NH4) to 3.95‐m soil depth was compared for 11‐mo‐old stands of eucalyptus (Eucalyptus grandis W. Hill ex Maiden), sesbania [Sesbania sesban (L.) Merr.], calliandra (Calliandra calothyrsus Meissner), markhamia [Markhamia lutea (Benth.) Schumann], and grevillea (Grevillea robusta A. Cunn. ex R. Br.) grown at two P levels (no added P and 500 kg added P ha−1) on a Kandiudalfic Eutrudox in Kenya. The trees were planted at a 1 by 1 m spacing in a randomized complete block with three replications. Added P had no effect on root length, soil NO3, and soil NH4 even though the soil was low in available P. Total root length was greater for calliandra (15.5 km m−2) than other trees (1.2–5.6 km m−2). The slope for the model of natural logarithm root length density (cm cm−3) as a function of soil depth was affected by tree species (P &lt; 0.01), indicating differences among trees in the tendency for deep rooting. Root length densities, averaged for the two P levels, were ≥0.1 cm cm−3 to depths of 2.2 m with calliandra, 1.8 m with sesbania, 1.2 m with eucalyptus, 0.45 m with grevillea, and 0.3 m with markhamia. Calliandra and sesbania reduced soil NO3 in the top 2 m by about 150 to 200 kg N ha−1 within 11 mo after establishment and effectively captured subsoil NO3. Fast‐growing trees with high root length densities can rapidly reduce subsoil NO3.

Oven drying improves the nutritional value ofCalliandra calothyrsus andGliricidia sepium as supplements for sheep given low-quality straw

Leaves from the tree legumes Gliricidia (Gliricidia sepium) and Calliandra (Calliandra calothyrsus) were fed as supplements (200 g dry matter) to sheep (n=3) given a basal diet of barley straw ad libitum. Tree leaves were fed either freshly harvested (F=fresh) or after drying at 60°C in a forced draught oven (D=dried). Voluntary intakes, digestibility and aspects of nitrogen (N) and phenolic compound metabolism were measured in all sheep. Drying decreased the condensed tannin (CT) content of Calliandra (F 117, D 82 g CT kg−1 DM). Total phenolics (TP) were significantly decreased when Gliricidia was dried (F 39, D 21 g TP kg−1 DM), and CT content was reduced from 20 g CT kg−1 DM to zero. Sheep given Gliricidia had higher rumen ammonia concentrations (73–85 mg N litre−1) than did sheep given Calliandra (37–40 mg N litre−1). For both species, drying significantly increased the voluntary consumption of straw, increased DM digestibility, decreased faecal N excretion and increased N balance. For calliandra, drying decreased the apparent degradability of N in the rumen (DNR) from 0·40 to 0·28 g N g−1 N ingested, and increased the apparent digestibility of N (ADN) in the post-ruminal tract from 0·20 to 0·52 g N absorbed g−1 N flowing into the small intestines. For Gliricidia, DNR decreased from 0·64 to 0·51 and ADN increased from 0·41 to 0·56. There were no significant effects of drying on rates of microbial N synthesis. The above changes were discussed in relation to changes in tannin content and it was concluded that drying facilitates the formation of protein–tannin complexes which protect proteins from degradation in the rumen. These proteins are subsequently released in the small intestines, thereby promoting an increased efficiency of dietary N utilisation. ©1997 SCI

Effects of supplementation with foliage from the tree legumes Acacia angustissima, Cajanus cajan, Calliandra calothyrsus and Leucaena leucocephala on feed intake, digestibility and nitrogen metabolism of sheep given maize stover ad libitum

Foliage (leaves, small-diameter stems and flowers and fruits if present) was harvested in March 1994 from Acacia angustissima, Cajanus cajan, Calliandra calothyrsus and Leucaena leucocephala and given as a supplement at four levels (0, 50, 100 and 150 g dry matter/day) to a diet of maize stover fed ad libitum to sheep. Sixteen sheep were used and divided into four groups of four, each with a mean weight of 18 kg. Each group was allocated at random to one of the legumes. Four 4 × 4 Latin square design experiments were carried out using 14-day periods and during the second week of each period feed intake, digestibility, nitrogen balance and microbial protein yield were measured. For each legume, other than C. calothyrsus, there was a significant increase ( P < 0.05) in dry matter intake as the level of supplement increased. For all four legumes, there was a significant increase ( P < 0.05) in digestibility of organic matter, nitrogen balance (NB) and microbial protein yield as the level of supplement increased. As judged by increases in intake of digestible organic matter and NB, A. angustissima gave the best response, followed by C. calothyrsus and L. leucocephala which were similar and then C. cajan gave the poorest response.

PERFORMANCE OF GRASS–LEGUME PASTURES UNDER COCONUTS IN INDONESIA

A series of grazed and cut experiments were conducted in Bali and North Sulawesi, Indonesia, between 1992 and 1994, to evaluate a range of selected forages for both intensive and extensive ruminant production under mature, tall coconuts. Yield, botanical composition and persistence of grass–legume mixtures were assessed under regular grazing and cutting regimes.In North Sulawesi, total dry matter yields of most grass–legume treatments were relatively stable over the two-year period but yields of legume components within treatments declined sharply. In Bali, the grazed plots maintained stable yield and legume components over the experimental period but yield and legume components of cut plots declined sharply. Paspalum malacophyllum and Setaria sphacelata cv. Splenda were productive and persistent grasses and formed weed-free swards but did not combine well with prostrate legumes. The erect growth habit of these grasses may limit their suitability in coconut production systems by impeding nut collection. The prostrate species Brachiaria humidicola and Stenotaphrum secundatum were slightly less productive but equally weed-free and persistent, and established rapidly from cuttings. S. secundatum also formed stable associations with prostrate legumes under grazing. Arachis pintoi cv. Amarillo and A. glabrata CPI 93483 were the most persistent of a range of prostrate legumes. The tree legume, Calliandra calothyrsus, showed promise as a productive cut-and-carry species.

Agronomic and Economic Evaluation of Organic and Inorganic Sources of Phosphorus in Western Kenya

AbstractMany soils in the highlands of East and Central Africa are depleted of soil nutrients, particularly P. Our objective was to compare cattle manure, Calliandra calothyrsus Meissner leaf biomass, and triple superphosphate (TSP) as sources of P for maize (Zea mays L.), both individually and as mixtures of organic (manure or calliandra) and inorganic (TSP + urea) sources. Field experiments were conducted on a Kandiudalf at two sites in western Kenya. Net benefits were computed as the difference between the value of additional maize yield accruing from nutrient inputs and the associated additional costs. Maize grain yield was 0.6 Mg ha−1 for application of urea without P. Application of 10 kg P ha−1 as organic, inorganic, and mixtures of organic and inorganic sources significantly increased maize yield. Grain yield for manure at least equaled and sometimes exceeded (P ≤ 0.05) yield for calliandra and TSP + urea. Net benefits in U.S. dollars (USD) for two seasons were highest for manure spot placed in the planting hole (293 USD ha−1), broadcast manure (255 USD ha−1), and broadcast TSP + 44 kg urea‐N ha−1 (313 USD ha−1 at P = 30 kg ha−1 and 98 USD ha−1 at P = 10 kg ha−1). Net benefits for calliandra leaf biomass were highest (136 USD ha−1) when biomass was valued at cost of production and integrated with TSP, such that it provided all the N for maize and TSP provided the additional P not supplied by calliandra. Calliandra valued at its opportunity cost as a protein supplement for dairy cattle was not an economic source of P. Sensitivity analyses suggest that organic materials most suitable for use as P sources have high P content and low cost of production.

NET N MINERALISATION IN COCONUT/NITROGEN FIXING TREE BASED SYSTEM

To study the net N mineralisation rates of coconut/NFT plantations, a field incubation technique was carried out. In this study, four types of NFT i.e. Acacia auriculiformis, Calliandra calothyrsus, Gliricidia sepium, Leucaena leucocephala and coconut monocropping were selected. Forty plastic tubes were inserted into the soil, to a depth of 15 cm at a distance of 2 m and l m away from coconut palm, for field incubation period of 2 weeks. Similarly another set of forty tubes were inserted for a 4 week field incubation period, after removing the previous set of tubes. Fresh soll samples (same depth) were also taken close to the inserted tubes on the day on which tubes were inserted for the estimation of initial N concentrations in the soil. Mineralised N concentrations were extracted by 2 M KCl and the net N mineralisation rates were calculated.&#x0D; &#x0D; Net N mineralisation was significantly higher (P= 0.001) 4 weeks after field incubation peniod than 2 weeks and also, the significant higher (P= 0.001) net N mineralisation was shown 2 m away from coconut than l m away from coconut. The highest net N mineralisation (4.9 ‑ 15.5 kgha-1) was found in Gliricidia site than in the other NFT sites, followed by Leucaena &gt; Calliandra &gt; Acacia. The lowest net N mineralisation (1.2 ‑ 2.2 kgha-1) was recorded in the coconut monocrop, either 2 weeks or 4 weeks incubation period. This study clearly indicated that growing NFTs with coconut enhances N availability in coconut lands and Gliricidia being the most promismig.

Growth and yield of eight agroforestry tree species in line plantings in Western Kenya and their effect on maize yields and soil properties

Between October 1988 and August 1992, field experiments were carried out in West Kenya to evaluate the suitability of Leucaena leucocephala, L. collinsii, Gliricidia sepium, Calliandra calothyrsus, Sesbania sesban, S. grandiflora, Senna siamea and S. spectabilis to provide a range of agroforestry products and services. The initial objective was to establish the growth rates and wood and leaf yields of these tree species, when planted in single rows. After the initial evaluation, it was evident that valuable additional information could be collected if the trees were converted to hedges and their effect on intercropped maize and soils was studied. At 21 months after planting, different species and provenances ranged in height between 3.5 and 6 m and varied considerably in phenotypic appearance. Wood production (1988–1990) varied from 3 to 33.8 t ha −1 and leaf production varied from 0.62 to 10.1 t ha −1. During intercropping (1990–1992), leaf production varied from 0 to 10.9 t ha −1. Maize yields were higher in association with Leucaena and Gliricidia than with Calliandra, Sesbania and Senna. Cumulative maize grain and stover yields over four seasons were positively correlated with the total amount of tree leaves applied ( r 2 range, 0.70–0.95). The effect of tree leaf mulch on crop yields decreased over time for all species. Leaves with high nutrient contents, which decompose fast ( Leucaena, Gliricidia, Sesbania) are likely to have been more effective in sustaining crop yields than leaves with lower nutrient contents ( Senna) or more complex decomposition patterns ( Calliandra). Simple “leaf input-crop output” budgets to calculate the reserves for N, P and K in different systems explained crop yield differences in some cases. Compared to the fertility status of “zero-mulch” control plots, the status of soil C, N, P, K, Ca, Mg and S was to varying degrees improved under Leucaena, Gliricidia and Sesbania, much less under Calliandra but not under Senna. First season grain yields were related to the soil fertility status at the end of the tree fallow. The results of these experiments suggest that under subhumid tropical conditions with soils of relatively poor nutrient status, where light and water are not likely to be the major limiting factors to crop production, the application of sufficient quantities of high quality tree mulch may positively influence maize yields. When agroforestry tree species with contrasting decomposition and nutrient release patterns are evaluated jointly, it is more difficult to demonstrate a general relationship between quantities of mulch applied and improvements in crop yields and soil fertility levels. Therefore, further chemical, physiological and phenotypic characterization of free species with potential for fallow and intercropping systems is required.

Composted shrub-prunings and other organic manures for smallholder farming systems in southern Rwanda

Organic manures are the primary source of crop nutrients in many African farming systems. The quantity of such materials that are available on farms and their quality are therefore important issues, especially in countries with limited land resources, such as Rwanda. In this study, different types of compost (including composted shrub-prunings) were compared with farmyard manure (FYM) and green manure (Calliandra calothyrsus) using beans (Phaseolus vulgaris) as test crops. The study confirmed the farmers’ general opinion that FYM has high manurial value for crop yields. Composts with P- and Ca-rich Tithonia diversifolia prunings were of similar quality as FYM or dung composts and had a higher fertilizer value than Calliandra ‘green manure’ (biomass transfer). However, the farmers’ perception of trees and shrubs as biomass and nutrient sources is still very low in Rwanda.

Predicting the decomposition patterns of tree biomass in tropical highland microregions of Kenya

Decomposition- and nitrogen-release patterns of biomass from three agroforestry multipurpose trees (Calliandra calothyrsus, Cordia africana and Grevillea robusta) were investigated in four contrasting environments (microregions) in the Kenyan tropical highlands during two cropping seasons. Dried leafy biomass was placed in 2-mm litter bags, buried at 15-cm depth and recovered after 2, 4, 7, 10, 15 and 20 weeks. Decomposition patterns were best described by first-order exponential decline curves. The decomposition rate constants ranged from 2.1 to 8.2 yr−1, and the rates of decomposition among the species were in the order: calliandra ≥ cordia > grevillea. There was a species-by-environment interaction during both seasons, but the nitrogen released did not follow such a pattern. Among the three tree species, calliandra released the highest amount of cumulative N, followed by cordia and grevillea. Using multiple regression techniques, decomposition pattern was described as a function of three groups of factors: biomass quality (N, C, lignin and polyphenol), climate (soil temperature and rainfall), and soil conditions (pH, soil organic C, total N and P). For all the species and factors combined, the adjusted R2 values were 0.88 and 0.91 for seasons 1 and 2, respectively. Among the three groups of factors, climate and biomass quality had the most influence on decomposition rates. Climatic factors accounted for 75% of the total rate of decomposition in season 1 (‘irregular’ season with less rainfall and more soil temperature fluctuations), whereas biomass quality factors were more influential in season 2 (‘regular’ season), accounting for 65% of the total variability.

Boosting Milk Production and Income for Farm Families: The Adoption of Calliandra Calothyrsus as a Fodder Tree in Embu District, Kenya

Boosting Milk Production and Income for Farm Families: The Adoption of <i>Calliandra Calothyrsus</i> as a Fodder Tree in Embu District, Kenya

The Effect of Cutting Management on the Fodder Yields of a Mixed Crop of Calliandra and Napier Grass

AbstractA field experiment was established to study the effect of cutting management on the fodder yields of a mixed crop of calliandra (Calliandra calothyrsus) and Napier grass (Pennisetum purpureum). Seven treatments were laid out as hedgerows in a randomized complete block design with four replications. Dry matter (DM) yields of calliandra increased significantly (P≤0.05) with cutting height. Most nutrients were not affected by this management except calcium and magnesium which declined. Dry matter yields of Napier grass declined with increasing cutting height of calliandra in the mixture. No significant differences in nutrient content were observed.

Multipurposes tree prunings as a source of nitrogen to maize under semiarid conditions in Zimbabwe

Time of pruning application and mixing prunings of varying qualities could be important management options to increase the rate of nitrogen recovery from multipurpose-tree prunings that are used as a source of nitrogen to crops. A field experiment was conducted in the semiarid zone of Zimbabwe to test this hypothesis, using prunings of calliandra (Calliandra calothyrsus) and leucaena (Leucaena leucocephala), alone and in mixtures, and maize (Zea mays) as the test crop. Time of pruning application significantly improved N uptake, N recovery, and grain yield of maize. Applying prunings of calliandra at maize planting was significantly better in terms of N uptake, N recovery, and grain yield than applying them four weeks after planting. However, with leucaena, time of prunings application had no significant effects on N recovery. Mixing prunings of leucaena and calliandra had no effect on maize N uptake, N recovery, and grain yield. Split application of available prunings during the crop growth cycle had no effect on N recovery compared to one-time application of entire amounts of prunings at planting.

The Influence of Time of Planting and Spacing on the Production of Fodder and Fuelwood in Associations of Calliandra calothyrsus and Pennisetum purpureum Grown on Contour Bunds in the Highlands of Burundi

SUMMARYThe best time to plant Calliandra calothyrsus in association with Pennisetum purpureum and the appropriate in-row spacing of Calliandra for fodder and fuelwood production when grown on contour bunds were investigated. Main plot treatments were Pennisetum planted in November 1988 and associated with Calliandra in February 1989, Calliandra planted in November 1988 and associated with Pennisetum in February 1989, and both species planted simultaneously in November 1988. Sub-plot treatments were three within-row spacings of Calliandra. Survival of neither species was affected by time of planting. Total treatment yields of the second and third years were not influenced by time of planting but lower yields of leaf and wood were obtained from the later-planted Calliandra. Total yields were not significantly influenced by the spacing, but leaf and wood yields of the Calliandra at the 25 cm spacing were greater than those at the 100 cm spacing although not significantly different from those at the 50 cm spacing. Neither the time of planting nor the spacing of Calliandra affected the yield of maize or beans grown in the interbund areas. Simultaneous planting of Calliandra and Pennisetum is recommended.

Decreasing rice and cowpea yields in alley cropping on a highly weathered Oxisol in West Sumatra, Indonesia

A hedgerow intercropping study was conducted for 7 years in West Sumatra, Indonesia on an acid and highly A1-saturated (72%) soil to determine growth and yield responses of tree hedgerows and upland rice and cowpea intercrops. Three tree species,Paraserianthes falcataria, Calliandra calothyrsus, andGliricidia sepium, and a no tree control were planted at three lime rates of zero, 375 kg ha−1, and liming to 25% Al+H saturation. Annual fertilizer inputs of 20 kg P and 50 kg K ha−1 were kept low to approximate low input farming systems. The trees were pruned 4 to 6 times per year and prunings applied to the intercrops.Paraserianthes andCalliandra grew vigorously, whileGiricidia grew poorly and was replaced after four years withFlemingia macrophylla. Hedgerow growth and yields were reported in a previous paper [Evensen et al., 1994].

Contrasting effects of roots and mulch from three agroforestry tree species on yields of alley cropped maize

In agroforestry associations, tree roots may influence crop yields both favorably, especially through mulch production and the improvement of soil fertility through root effects, and unfavorably through above- and below-ground competition. A field experiment was conducted on a shallow sandy Plinthic/Ferric Acrisol in the sub-humid savanna of central Togo in order to compare the competitiveness of Gliricidia sepium, Calliandra calothyrsus and Senna siamea hedges when grown in association with maize. The effect of hedge distance on maize yields was tested by measuring yield gradients in unilaterally open alleys. In 6.4-m-wide alleys, maize yields were lower than in the sole cropping control because of the reduction in cropped surface and a yield depression near the Calliandra hedges. With increasing hedge distance, yields per row increased over the control yields in alley cropping with Gliricidia, but not with Senna and Calliandra. Root barriers between hedges and crops increased maize yields in the Calliandra plots, indicating a high competitiveness of the root system of this species. In the Senna and (non-significantly) Gliricidia plots, maize yields at the interface were reduced rather than increased by the root barriers. For this, the reduction of the crop rooting volume and of favorable hedge root effects on soil conditions are discussed as possible reasons. Tree species with highly competitive root systems, like Calliandra at this site, should be used in fallow improvement systems rather than in agroforestry associations.