Preliminary evaluation of potential fodder quality in a range of Leucaena species

Twenty-two taxa and five interspecific hybrids of Leucaena, grown together on a site in Houduras, were evaluated in terms of their potential value as tropical fodder crops. Content of crude protein, organic matter, acid detergent fibre, neutral detergent fibre, total tannin and condensed tannin (proanthocyanidin), as well as in vitro digestibility, were estimated in dried leaf samples, and the accessions ranked according to each of these criteria. The relative palatability of thirteen of the taxa and two of the hybrids was also assessed in a 'cafeteria' trial using fresh leaf material fed to sheep over an 18 day period. Protein, digestibility and palatability estimates, together with previously published yield data, were used to construct three indices of fodder potential, to allow direct comparisons between taxa. The most promising taxa according to these criteria included L. shannonii subsp. shannonii, L. collinsii subsp. zacapana and L. multicapitula, all of which achieved higher scores than the much better-known L. leucocephala subsp. glabrata in the index derived from crude protein and digestibility. When yield and palatability were included in the indices, the very high palatability of L. leucocephala gave it the highest score overall. The most unpromising taxa included L. pulverulenta, L. trichandra, L. esculenta (subsp. esculenta and subsp. matudae), and L. greggii. This revised version was published online in August 2006 with corrections to the Cover Date.     

Open-pollinated, interspecific F1 hybrid seed orchards of Leucaena: I. Rootstock effects

Seed orchards of Leucaena were established at two experimental sites in Hawaii to produce either triploid or tetraploid interspecific hybrid seed by interplanting clonal self incompatible diploid (L. diversifolia, L. esculenta) or tetraploid (L. pallida) species with self- compatible L. leucocephala lines and the F1 hybrid of L. diversifolia (2n = 4x) × L. leucocephala. The seed parents were grafted onto three seedling rootstocks (L. diversifolia (2n = 4x), shrubby L. leucocephala, and giant L. leucocephala) to compare rootstock effects on scion growth. This paper reports on the effects of rootstock on scion growth during the first year based on total truck cross sectional area, height growth, and crown habit. In the triploid seed orchard, rootstock significantly affected the growth of four of the six clones, while in the tetraploid orchard the growth of two of the five clones was significantly affected by rootstock. Crown habit was independent of rootstock. Our study suggests that rootstock effects depend on the specific scion and rootstock combination, and site. This revised version was published online in June 2006 with corrections to the Cover Date.     

Forage yield and compositional analysis of Leucaena species and hybrids adapted to cool sites

Four species of Leucaena (L. leucocephala, L. diversifolia 2n and 4n, andL. pallida) and three interspecific hybrids KX1 (L. diversifolia × L. pallida), KX2 (L. leucocephala × L. pallida), and KX3 (L. leucocephala × L. pallida) were evaluated for forage yield on a cool upland site at the Mealani Research Station on the island of Hawaii (900 m elevation). Two-month-old seedlings were planted at a density equivalent to 40,000 trees/ha and coppiced (harvested) every six months for a two-year period. Leaf material collected from the plots was oven-dried, finely ground, and evaluated for forage components and digestibility.Two Holstein steers fitted with cannulae in the rumen and proximal duodenum were used to conduct a replicated trial to examine rumen and post-rumen dry matter and crude protein digestibility of leaf material. Nylon bags containing leaf material from K636 (L. leucocephala), KX2 (L. leucocephala × L. pallida), or K376 (L. pallida) were suspended in the rumen for periods of 0, 4, 8, 12, 24, 36, and 48 hours. Weight loss was measured and nitrogen content of each sample was determined using a macro-Kjeldahl procedure. Subsequently, rumen-incubated material was placed in nylon bags, inserted into the duodenal cannulae of the two steers and collected in the feces for periods of 24 h after insertion.Results indicate that varieties and hybrids of Leucaena are adapted to cool sites and produce good yields of high quality forage. No significant difference was found in either ruminal or intestinal dry matter or crude protein disappearance between K636 and KX2 whereas K376 was significantly lower for both values. Nearly 40% of dietary crude protein in the K636 and KX2 leaf material escaped ruminal digestion whereas nearly 70% was non-digested for K376. For K636 and KX2, intestinal availability of that protein which escaped ruminal digestion was nearly 50% whereas only 20% of ruminal escape protein of K376 was available in the intestines. Because KX2 produced higher forage yields, plantings on cool sites would favor the use of KX2 over K636 if animal acceptability and rumen retention of dry matter are not problems.     

Open-pollinated, interspecific F1 hybrid seed orchards of Leucaena: II. Analysis of seedlings

Seed produced on a single clone of a self-incompatible Leucaena species interplanted with cross compatible pollen donors of another species should theoretically be interspecific hybrid seed. This paper reports on the parentage of seed produced on two clones (K804, K953) of L. pallida produced in two interspecific seed orchards during the first year of growth. Grafting was used to propagate the two L. pallida clones and the interplanted pollen donors including L. leucocephala (K420, K481, K636) and the F1 hybrid KX3 (L. diversifolia K156 × L. leucocephala K636). Seed was produced on L. pallida K804 in one orchard, and on L. pallida K953 in the other orchard. Seeding leaf morphological characteristics including pinnule pairs per pinna, pinnule width and general appearance were used to determine parentage of seed produced on the L. pallida clones in each orchard. L. pallida K804 produced 81% interspecific hybrid seed while L. pallida K953 only produced 27% hybrid seed. These results suggest a breakdown of the gametophytic self-incompatibility mechanism in L. pallida, particularly in the K953 clone. The feasibility and possible improvement to this seed production system are discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Growth and yield of maize alley cropped with Leucaena leucocephala and Faidherbia albida in Morogoro, Tanzania

This study examined the effect of alley cropping of Leucaena leucocephala and Faidherbia albida on wood biomass, maize grain yield and soil nitrogen status. The treatments were: trees planted alone at 1 × 5 m spacing; trees intercropped with maize and a sole maize crop. Mulch biomass averaged 6.18 and 0.97 t ha⁻¹ for L. leucocephala and F. albida, respectively. Corresponding wood production was 1.71 and 1.11 t ha⁻¹. Both total N and inorganic N (NO ₃ ⁻ –N plus ₄ ⁺ –N) were higher under F. albida and lowest under L. leucocephala. Similarly, foliar N concentration in maize was higher in plots intercropped with F. albida and least in L. leucocephala intercropping. Maize grain yield was little affected by the tree intercrop as competition for resources was reduced through periodic pruning and clean weeding. There was no gain in maize grain yield due to the presence of L. leucocephala and F. albida. These results suggest that alley cropping in Gario is justified for wood production but not for increasing maize grain yield. This revised version was published online in June 2006 with corrections to the Cover Date.     

Role of income diversification in protecting natural forests: evidence from rural households in forest margins of Sri Lanka

Ranchers need alternative livestock feeds when herbaceous forages become limiting in summer. Our objectives were to determine: (1) leaf and stem biomass components, (2) nutritive value [in vitro dry matter digestibility (IVDMD), total nonstructural carbohydrate (TNC), N, and N digestibility] of leaves for animal browse, (3) concentration of the secondary metabolites robinin and mimosine, and (4) in vitro leaf and bark toxicity for black locust (Robinia pseudoacacia L.) and mimosa (Albizia julibrissin Durz.), respectively, pollarded at 50 cm in Arkansas, USA. Black locust exceeded mimosa for every yield component (leaf mass tree⁻¹, leaves shoot⁻¹, shoots tree⁻¹, shoot mass tree⁻¹, stem basal area, and biomass tree⁻¹) except mass leaf⁻¹. Projected yields were 1,900 and 1,600 kg leaves ha⁻¹ for black locust and mimosa, respectively, assuming a population of 12,300 trees ha⁻¹. Mimosa leaves had greater IVDMD, TNC, and N digestibility than black locust. Mimosa leaves exceeded the nutritional N requirements of growing cattle (Bos taurus L.) and goats (Capra hircus L.), but protein supplementation would be needed for growing goats grazing black locust leaves. Tissue concentrations of secondary metabolites robinin and mimosine were below detectable limits in black locust and mimosa, respectively. The extract of black locust bark, but not leaves, was toxic to bioassayed African green monkey (Cercopithecus aethiops L.) cells. Either black locust or mimosa could provide moderate quantities of high quality, rotationally grazed forage for goats during summer months when herbaceous forage may in short supply.     

Effect of freezing-thawing on nitrogen mineralization in vegetation soils of four landscape zones of Changbai Mountain

• Introduction   

We studied the effect of freezing-thawing on nitrogen (N) mineralization of four vegetation soils from typical vegetation zones of Changbai Mountain with a laboratory incubation experiment. The soils were treated with two levels of soil water content, representing the low and high soil water contents found during late autumn and early spring in Changbai Mountain, respectively, and underwent cycling of freezing at −5 or −25°C and thawing at 5°C up to 15 times.     

Root preparation technique and storage affect results of seedling quality evaluation in Norway spruce

Evaluation of tree seedling quality is necessary for improving technology for forest nursery production and seedling handling. Nutrient status can be measured to determine seedling quality, but it can be affected by seedling handling techniques. In this study effects of root preparation technique and storage regime on content of macro nutrients (N, P, K, S, Ca, Mg) in fine roots of Norway spruce (Picea abies (L.) Karst.) plants were investigated. The root preparation techniques were: (a) rinse in tap or (b) deionised water, and (c) dry preparation. These techniques were tested on seedlings subjected to four storage regimes: (1) no storage, (2) deep freezing below −20°C, and long-term (3) cold (+1 to +3°C) and (4) frozen (−3 to −4°C) storage. From the results it was concluded that the nutrient status in needles is not sufficient to describe the whole plant nutrient status in stored dormant plants, fine roots should also be included. The results also showed that deep freezing of fine roots before nutrient analyses should be avoided. Losses of K, P, S, and Mg were substantial with this method. Deionised water or dry preparation is preferred since tap water contains substantial amounts of ions that may affect the analyses.     

Effects of seed water content and storage temperature on the germination parameters of white spruce, black spruce and lodgepole pine seed

The effect of seed water content (WC) (2–3, 5–6 and 22–25%, on a fresh weight basis), storage temperature (+4, −20, −80 and −196°C) and storage duration (6, 12, 24, 48 and 60 months) on the germination of white spruce (Picea glauca (Moench) Voss), black spruce (Picea mariana (Mill.) B.S.P.) and lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) seed was investigated. Germination of white spruce control (untreated) seeds and seeds adjusted to 2–3% and 5–6% WC declined after 48 months of storage at −80 and −196°C, with a further decline at 60 months at −20, −80, −196°C. Germination remained high when control white spruce seeds and seeds with 2–3, 5–6% WC were stored at +4°C, over all storage durations. Generally, black spruce and lodgepole pine exhibited high germination at all storage temperatures at 2–3% and 5–6% WC as well as the control (untreated) seed, for up to 60 months in storage. Germination declined for all three species when seed was conditioned to 22–25% WC. This loss in germination was partially recovered in white spruce seed stored at +4, −20 and −80°C after storage durations of 24, 12 and 48 months, respectively, and in black spruce seeds stored at −20 and −196°C after storage durations of 24 months. Mean germination time (MGT) was relatively constant for all species, under all conditions, except for seed conditioned to 22–25% WC, where MGT increased for white spruce seed stored 48 months at −80 and −196°C, and for black spruce seed stored 24 months at +4 and −80°C and 60 months at −196°C. These results show that the optimal storage temperatures are 4°C for white spruce, and 4, −20, −80, and −196°C for black spruce and lodgepole pine, and 2–6% water content is optimal for all 3 species at these temperatures.     

Growth Parameters and Nutrient Content in Four Multipurpose Tree Species with Potential Characteristics for Agroforestry Systems in a Cerrado Region in Botucatu,São Paulo State,Brazil

Abstract

In order to evaluate growth characteristics, adaptability, biomass production, nutrient recycling, nutrient distribution and the ability to regenerate degraded land, a trial using four multipurpose tree species (Leucaena leucocephala, Leucaena diversifolia, Acacia melanoxylon and Mimosa scabrella) was undertaken over two years in a distrophic red yellow latosol (oxisol) following a randomized block experimental design with four replications.

At the age of two years, A. melanoxylon and L. diversifolia were the tallest species (5.25 and 4.97 m, respectively) and A. melanoxylon and M. scabrella had the largest diameters at 20 cm from tree base.

Mimosa scabrella and A. melanoxylon had the highest dry matter production and quantity of nutrients in the above ground biomass. In all species, the highest nutrient contents were found in the leaves, followed by branches and stems. From all species, the highest Nutrient Utilization Efficiency Indexes were obtained for sulphur, phosphorous, and magnesium; L. diversifolia was the most efficient for nitrogen, potassium, calcium, sulphur, and manganese, while A. melanoxylon was the most efficient for phosphorus, magnesium, boron, iron, and zinc. Litter production levels over a three month period were as follows: M. scabrella > A. melanoxylon > L. diversifolia > L. leucocephala. Litter nutrient content was higher in M. scabrella than in the other species.     

Spatial and temporal gradients of earthworm casting activity in alley cropping systems

The amounts of earthworm surface casts were monitored for 200 days after commencement of casting in three alley cropping experiments of different ages and hedgerow species. Casts were collected twice per week in transects from under the hedgerow to the middle of the interrow space. Average annual cumulative amounts of casts were higher in alley cropping systems with one to five years of cropping than in the no-tree control. After five years of cropping, amounts of casts were similar in all treatments. Within the alley cropping systems, casting activity was highest immediately under the hedgerows and decreased towards the middle of the interrow space. In systems using Leucaena leucocephala as hedgerow species, the hedgerow to interrow space gradient of casting activity became more pronounced with increasing length of cropping. Casting activity in the interrow space was reduced by 12%, 55%, 80% and 86% in the first, fourth, sixth and seventh year of cropping, respectively, compared to the casting activity under the hedgerows. Senna siamea, which produced a more recalcitrant mulch, did not show such a strong decline in casting in the interrow space. In a Dactyladenia barteri system, the difference in casting between interrow space and hedgerows was insignificant. With perpendicular distance from the hedge, largest gradients in casting activity occurred close to the hedgerows with up to −4.00 Mg ha⁻¹ cm⁻¹ in L. leucocephala but only −1.23 and −0.76 Mg ha⁻¹ cm⁻¹ in S. siamea and D. barteri, respectively. The shading effect of trees and a relatively low level of soil disturbance is apparently more beneficial for earthworms in a cropped system than a high supply of readily available food from fast decomposing L. leucocephala prunings. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of priming on the germination of<Emphasis Type="Italic">Peltophorum dubium</Emphasis> seeds under water stress

Peltophorum dubium seeds provided by Anhembi, SP were scarified in 98% H2SO4 for 15 rain to overcome mechanical dormancy. Seeds were primed in solutions of 0.2% Captan at 10℃ and 27℃, PEG 6000 -1.0 MPa at 10℃ and 27℃, 0.5 mol KNO3, 0.75 Mol KNO3, 1.0 Mol KNO3. Eight treatments including the primed seeds and nonprimed seeds, five replicates with 100 seeds for each treatment, were set to 15-cm-Petri dish with double filter paper moistened with testing solution PEG in refrigerator at 27℃. For the experiments of all the groups, osmotic potential were 0.0, -0.2, -0.4, -0.6, -0.8, -1.0, -1.2, and -1.4 MPa. P. dubium seeds were also set to water stress experiment in rolled paper with PEG solutions from 0.0 to -1.0 MPa.Germination percentage decreased with the increase of PEG concentration. Control group had a better germination percentage than other groups. Germination hardly occurred in PEG -1.4 MPa.     

Biomass Production and Chemical Composition of Moringa oleifera under Different Management Regimes in Nicaragua

The effects of different planting densities (250,000, 500,000 and 750,000 plants ha⁻¹) and cutting frequencies (45, 60 and 75 days) on the biomass production and chemical composition of Moringa oleifera was studied in a completely randomised split plot design with four blocks, in Managua, Nicaragua, located geographically at 12°08′15′′ N and 86°09′36′′ E. The 75 day cutting frequency produced the highest fresh matter yield, 100.7 and 57.4 Mg ha⁻¹ year⁻¹, and dry matter (DM) yield, 24.7 and 10.4 Mg ha⁻¹ year⁻¹, during the first and second year, respectively. All planting densities produced the highest DM yield at 75 day cutting frequency. In the first year, the density of 750,000 plants ha⁻¹ produced the highest fresh matter yield, 88.0 Mg ha⁻¹ and highest DM yield, 18.9 Mg ha⁻¹, but in the second year the density of 500,000 plants ha⁻¹ gave the highest yields, 46.2 Mg ha⁻¹ and 8.1 Mg ha⁻¹, respectively. During the first year, DM (22.8%), neutral detergent fibre (NDF) (30.8%) and ash (9.14%) contents were highest and in vitro DM digestibility (IVDMD) (68.2%) was lowest in the longest cutting interval, while contents of crude protein (CP) (22.8%) and acid detergent fibre (ADF) (22.8%) were not affected significantly by cutting frequency. In the second year, DM and CP contents and IVDMD were not significantly affected by cutting frequency, whereas NDF, ADF and ash contents were lowest in the 60 day cutting frequency. Planting density had no significant effect on chemical composition or IVDMD. These data suggest that Moringa forage could be an interesting protein supplement for ruminants.     

Condensed tannins in Leucaena and their relation to psyllid resistance

Leucaena species and hybrids were examined to determine the relative content of condensed tannins and its relationship to susceptibility to defoliation by the Leucaena psyllid (Heteropsylla cubana). The interspecific Leucaena hybrid KX2 (L. leucocephala × L. pallida) was examined for variability of condensed tannin levels. A broad range of condensed tannin values were found which indicate potential for improved forage value through selection for KX2 trees with lower condensed tannin while maintaining psyllid resistance. A significant correlation was not found linking condensed tannins and psyllid resistance.     

Optimizing SSR-PCR system of Panax ginseng by orthogonal design

An orthogonal design was used to optimize SSR-PCR amplification system using Panax ginseng genomic DNA as template. Four levels of five factors （DNA template, Taq DNA polymerase, Mg^2＋, primer, and dNTP） and annealing temperature have been tested separately in this system. The results demonstrated the reaction efficiency was affected by these factors. Based on the results, a stable, productive and reproducible PCR system and cycling program for amplifying a ginseng SSR locus were obtained： 20 μL system containing 1.0 U Taq DNA polymerase, 2.0 mmol·L^-1 Mg^2＋, 0.2 mmol·L^-1 dNTPs, 0.3 μmol·L^-1 SSR primer, 60 ng· μla^-1 DNA template, performed with a program of 94℃ for 5 min, 94℃ for 30 s, annealing at 56.3℃ for 30 s, 72℃ for 1 min, 37 cycles, finishing at 72℃ for 7 min, and storing at 4℃.     

Profiles of carbon stocks in forest, reforestation and agricultural land, Northern Thailand

A study was conducted to assess carbon stocks in various forms and land-use types and reliably estimate the impact of land use on C stocks in the Nam Yao sub-watershed (19°05'10"N, 100°37'02"E), Thailand. The carbon stocks of aboveground, soil organic and fine root within primary forest, reforestation and agricultural land were estimated through field data collection. Results revealed that the amount of total carbon stock of forests (357.62 ± 28.51 Mg·ha-1, simplified expression of Mg (carbon)·ha-1) was significantly greater (P＜ 0.05) than the reforestation (195.25 ±14.38 Mg·ha-1) and the agricultural land (103.10±18.24 Mg·ha-1). Soil organic carbon in the forests (196.24 ±22.81 Mg·ha-1) was also significantly greater (P＜ 0.05) than the reforestation (146.83± 7.22 Mg·ha-1) and the agricultural land (95.09 ± 14.18 Mg·ha-1). The differences in carbon stocks across land-use types are the primary consequence of variations in the vegetation biomass and the soil organic matter. Fine root carbon was a small fraction of carbon stocks in all land-use types. Most of the soil organic carbon and fine root carbon content was found in the upper 40-cm layer and decreased with soil depth. The aboveground carbon(soil organic carbon: fine root carbon ratios (ABGC: SOC: FRC), was 5:8:1, 2:8:1, and 3:50:1 for the forest, reforestation and agricultural land, respectively. These results indicate that a relatively large proportion of the C loss is due to forest conversion to agricultural land. However, the C can be effectively recaptured through reforestation where high levels of C are stored in biomass as carbon sinks, facilitating carbon dioxide mitigation.     

Eine weitere Beobachtung zur Frage des Läusestreuens

Zusammenfassung Neben dem in einer früheren Darstellung behandelten Herunterfallen von L?usen, die sich beim Umherlaufen auf der Kleidungs-oberfl?che gegenseitig mit den Beinen verkrallen, kommt als Ursache für das L?usestreuen auch die K?ltestarre der L?use in Frage, die bei Temperaturen in der N?he von 0° eintritt. Die Beobachtung an verlausten Kleidungsstücken bei −6°C zeigte, da? bei Windst?rke 5–6 L?use im Zustand der K?ltestarre von dem Luftzug, bereits von den Stoffunterlagen abgerissen werden k?nnen.     

Microclimate of a natural pasture under planted Robinia pseudoacacia in central Appalachia, West Virginia

The conditions under which forages yield more under tree canopies than in open fields are not well understood. This study was conducted to determine how microclimate experienced by forages in central Appalachia is modified by black locust (Robinia pseudoacacia L.) tree canopies. The effect of tree row location relative to forage growing point was evaluated for its impact on soil water, photosynthetically active radiation (PAR), red/far-red ratio, and surface soil temperature. There was no consistent spatial dependency relating tree rows to soil water levels. While daily PAR decreased as the time under shade increased, the level of PAR under tree canopies nearly doubled as cloud cover increased from 0 to 25%. The red/far-red ratio decreased from 1.16 to 0.2 over forage growing between tree rows compared to forage within tree rows. Surface soil temperature remained nearly constant (1.5–2 °C increase) during sunny days under tree canopies but increased 8–12 °C by mid afternoon at unshaded sites depending on soil water levels. Forages under black locust trees experienced less extreme variation in both daily PAR and temperature than unshaded forages, thus reducing the metabolic cost of adaptation to extreme conditions. This revised version was published online in June 2006 with corrections to the Cover Date.     

Nickel-catalyzed carbonization of wood for coproduction of functional carbon and fluid fuels I: production of crystallized mesoporous carbon

Japanese larch wood loaded with nickel (1%–4%) alone or with nickel and calcium (0.25%–1.5%) was carbonized at 800°–900°C for 0–120min with a heating rate of 5°–20°C min⁻¹ in a helium flow of 5.8−46.4 ml STP cm⁻² min⁻¹ to examine the influence of these variables on the crystallization of carbon (the formation of T component) and the development of mesoporosity. From the obtained results, reaction conditions suitable for effective production of carbon with the dual functions of adequate electroconductivity and adsorption capacity in liquid phase were established, thereby explaining the factors that govern the process. It was also confirmed that mesopore having a diameter of about 4 nm was selectively produced at the cost of specific (BET) surface area in parallel with the formation of T component. This result provided good insight into how the simultaneous dual function could be realized.     

Field performance potential of a somatic interior spruce seedlot

This study defined the field performance potential for 34 genotypes that composed a somatic seedlot of interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry ex. Engelm.) crosses, white spruce (P. glauca (Moench) Voss) crosses, or a mixture. Each genotype was measured for morphological attributes: height, diameter, shoot dry weight, root dry weight, shoot-to-root ratio, height-to-diameter ratio at time of lifting. Each genotype was also measured for physiological attributes of cuticular transpiration (TFD_cut), osmotic potential at turgor loss point (Ψ_tlp) and freezing tolerance (index of injury at −6°C and −4°C; II_@−6 & II_@−4) during inactive and active shoot growth phases. Shoot growth potential (SGP = length of new leader elongation) and root growth potential (RGP) were conducted under four environmental regimes: nutrient-rich/well-watered, nutrient-poor/well-watered, low root temperature, and planting stress conditions. The somatic seedlot met target height, diameter and RGP standards for a plantable seedling crop in British Columbia, Canada, though genotypes differed in morphology at time of lifting. These genotypes also differed in their measured physiological attributes (TFD_cut, Ψ_tlp, II_@−6 and II_@−4) at time of lifting and during active shoot growth. Genotypic differences were also found for SGP and RGP under different testing environments. A stock quality assessment program describing elite genotypes within a seedlot can aid foresters in applying benefits of clonal forestry. Raymund S. Folk is now self employed.