Improvement and Culture of Nitrogen Fixing

May 2006 Volume 9 No.1 Working Party 2.08.02

Web page at: http://www.iufro.org/science/divisions/division-2/20000/20800/20802/

Message from the Coordinator WP 2.08.02

Antoine Kalinganire and management of production areas and genetic World Agroforestry Centre improvement. I invite Working Party members to give to the ICRAF West and Central Africa new officers their usual support to further our communication BP 320 Bamako, Mali and cooperation activities. Tel: +223 222 3375; Fax: +223 222 8683 Email: [email protected] The XXII IUFRO World Congress held in Brisbane, in August 2005. Many members of the NFT Working Party attended this congress. Unfortunately neither I nor other This is the first time we have produced only an electronic officials of our Working Party could not attend. version of the NFT News. Hard copies will not be available to Congratulations to all members who managed to make their members in the foreseeable future. It is really unfortunate as way to Brisbane and thanks for your contribution to the most members in developing countries do not have access to Congress. the internet system. I thank you also for your strong support shown over since I In the last issue of NFT News (vol. 8 no. 1), I appealed for a took over as Coordinator. Please help keep our Working Party sponsor to help with the reproduction and the distribution of to grow and become more productive. Finally, I extend my the NFT News. However, there has not yet been a positive welcome to new members, the NFT family looks forward to response but we have not lost hope! This wonderful linking sharing your experience with more than 1200 members in paper should be distributed to members of the more remote over 100 countries. parts of the world. It costs only US$5000, mainly for production and distribution, for each issue of the Newsletter. The editorial board contributes its time voluntarily. If you feel you can help and/or you know somebody who can help, Early results of a progeny trial of please contact me. I take this opportunity to thank members supporting NFT News by sharing their information and junghuhniana in research results. Thailand After Mr Khongsak Pinyopusarerk stepped down from coordinating the IUFRO Working Party 2.08.02, Dr Dietrich Piset Luechanimitchit Forest Management and Forest Werner of the Phillips-Universitat Marburg Fachberich Products Research Office Biologie also stepped down at the end of her 10-year term as a Royal Forest Department WP Deputy Coordinator. Dr Werner contributed in the Bangkok 10900 Thailand build-up of our working party and I ask you to join me and Tel : +66 2 5614292-3 ext 445 congratulate her for a job well done. IUFRO has nominated Fax : +66 2 5799576 Email : [email protected] two new deputies: Dr Ousman Diagne (Senegal) and Mr Vitoon Luangviriyasaeng (Thailand) for a 5-year period Introduction (2006-2010) that will culminate with the 23rd IUFRO World Casuarina junghuhniana Miq. is a native of the eastern part of Congress in Seoul, Korea in 2010. Dr Diagne (email: Indonesia (east Java, Bali and parts of the Lesser Sunda [email protected]) is a soil microbiologist with the ‘Centre archipelago), occurring from sea level to 3100 m National de Recherches Forestières’ of the ‘Institut Sénégalais (Pinyopusarerk and House, 1993). In 1900s, A male hybrid of de Recherches Agronomiques’ and his main research fields C. junghuhniana x C. equisetifolia was introduced to Thailand include the selection of root endophytes (Rhizobium from Penang or Singapore as an ornamental and has been and mycorrhizal fungi) from different ecozones, the potential planted throughout the country. The popularity of this of nitrogen-fixing tree and the -soil-microsym- biont relationships. Mr Luangviriyasaeng (email: casuarina is due to its excellent growth rate, very good stem [email protected]) is a forest scientist with the Silviculture form, and wide adaptability to different site conditions. It is Research Group of the Royal Forest Department and his main useful for underground piling and supporting raft for construc- research fields include the domestication of tropical acacias tion work as well as for fuel and charcoal. In Thailand and , N-fixing species site matching, and the design propagation of this male hybrid is by vegetative methods.

Improvement and Culture of Nitrogen Fixing Trees Material and Methods Performance of some Australian A progeny trial of C. junghuhniana was established in 2003 in Kanchanaburi province (latitude 13° 58' N, longitude 99° acacias in the Sahelian conditions 18' E, altitude 45 m, mean annual rainfall 900-1000 mm, mean annual temperature 29°C). The soils are sandy and silty of Mali loam with pH 6.7. The trial, consisting of 184 families from Souleymane Keita 20 provenances and land races (including (the local hybrid World Agroforestry Centre (ICRAF) clone as control), was planted using a row-column design ICRAF West and Central Africa with 8 replicates, 4 trees/plot at a spacing of 3.0 m x1.5 m. At Ségou, Mali the age of two years, tree height, diameter and survival were Tel: 223 - 232 2466; Fax: 223 - 232 0389 assessed and analysed using DataPlus 2 (Kron et al. 1999) and Email: [email protected] Genstat 5.32 (Payne et al. 1987) statistical programs. Antoine Kalinganire Results and Discussion World Agroforestry Centre (ICRAF) Growth (height and diameter) and survival of all seedlots ICRAF West and Central Africa (including control) are shown in the group of each provenance BP 320 Bamako, Mali Tel: (223) 222, Fax: (223) 222 8683 (Table 1). At this preliminary stage, an analysis of variance on Email: [email protected] height, diameter and survival showed significant differences in growth and survival between provenances. There were also Bokary Kaya differences between families within provenances. The five World Agroforestry Centre (ICRAF) provenances from Indonesia and a planted stand in NSW ICRAF West and Central Africa Australia (CSIRO Seedlots: 17844, 17877, 19490, 17878 and BP 320 Bamako, Mali 17559) were superior to the other provenances. Some of the Tel: 223 - 232 2466; Fax: 223 - 232 0389 introduced provenances grew betterand had higher survival Email: [email protected] than the local hybrid control. However, more time is needed to determine the best family/provenance of this species. The Introduction There are some1350 species in the legume genus Acacia trial will be maintained until mature growth and other extending around the globe particularly in Africa, Asia and characters, such as stem form, branching habit and health, are Australia. The species of this genus are exploited in their assessed. natural habitats and in plantations for many purposes (Brockwell et al. 2005). These nitrogen-fixing trees and References shrubs grow over a wide range of environments from arid Kron, A., Williams, E.R., Harwood, C. and Heng, S.1999. DataPlus deserts to the humid tropics, from near sea level to altitudes 2: CSIRO: Forestry and Forest Products, Canberra. 93p. exceeding 1000 m, and highly acidic to highly alkaline soils Payne, R.W., Lane, P.W., Ainsley, A.E., Bicknell, K.E., Digby, (Midgley and Turnbull 2003). Their adaptability and rapid P.G.N., Harding, S.A., Leech, P.K., Simpson, H.R., Todd, A.D., Verrier, P.J., White, R.P., Gower, J.C. and Tunnicliffe, early growth have made them popular for planting on W.G. 1987. Genstat 5. Reference Manual, Oxford University degraded lands in Africa and elsewhere. Press, Oxford. 749p. Pinyopusarerk, K. and House, A.P.N. 1993. Casuarina: an annotated Increasing population and livestock pressure on natural forests bibliography of C. equisetifolia, C. junghuhniana and and a series of droughts have contributed to deforestation and C. oligodon. International Centre for Research in severe land degradation in the Sahel. Thus there is a growing Agroforestry, Nairobi. 298p. need of restore degraded land and to meet the high demand for forest products and services such as fuelwood, charcoal, Table 1. Growth of Casuarina junghuniana provenances poles for construction, windbreaks and land rehabilitation. (2 years after planting) in Kanchanaburi province, Thailand. Multipurpose Australian acacias have the potential to form an integral component of agricultural systems in the Sahelian Prov. CSIRO Location Altitude DBH HT Survival No. Seedlot (m) (cm) (m) (%) zone of West Africa. In Maradi, southern Niger (annual No. rainfall <500 mm), more than a decade of research has 1 18952 Mt. Willis, East Java, Indonesia 1500 2.9 3.6 51 identified well-adapted Australian acacias such as Acacia 2 18948 Mt. Kawi, East Java, Indonesia 2000 2.8 3.6 45 colei, A. torulosa, A. tumida and A. elachantha (Cunningham 3 18951 Mt. Arjuno, East Java, Indonesia 2100 2.9 3.7 47 and Abasse 2005). These acacias grow rapidly (annual mean 4 18950 Mt. Bromo, East Java, Indonesia 1600 3.0 3.8 56 tree height of more than 2.8 m after 15 months), are well 5 18954 Mt. Bromo, East Java, Indonesia 2500 2.9 3.5 50 6 18949 Mt. Argopuro, East Java, Indonesia 1500 3.0 3.5 47 adapted to infertile soils, produce large quantities of 7 18849 Kintamani, Bali, Indonesia 1500 2.9 3.6 57 fuelwood, construction timber, can be used as windbreaks and 8 18848 Bukit Abang, Bali, Indonesia 1500 3.2 4.1 62 improve soil fertility. In Senegal, under comparable ecological 9 17878 Noelmina River, Timor, Indonesia 170 3.6 4.9 81 conditions A. holosericea, A. linarioides and A. tumida 10 17877 25 Km SW Soe, Timor, Indonesia 550 3.8 5.0 72 showed the best performance (Diaminatou Sanogo 2005, 11 17844 Old Uhak, NE Wetar, Indonesia 5 4.0 5.1 78 12 18953 Mt. Arjuno, East Java, Indonesia 1350 3.1 3.8 56 personal communication). 13 19489 Kapan, Kupang, Timor, Indonesia 600 3.6 4.7 75 14 19490 Camplong, Timor, Indonesia 600 3.7 4.9 84 In Mali, under similar conditions, there is a need to 15 19491 Buat, Soe, Timor, Indonesia 800 3.5 4.7 76 evaluate Australian acacias mainly for restoration of soil 16 17559 Coffs Harbour, NSW, Australia 100 3.7 4.6 83 fertility on degraded land, for firewood, and poles for 17 19239 KARI-Muguga Kenya 2060 2.9 3.6 44 18 19240 Muka Mukuu , Kenya 1460 2.8 3.5 30 construction. This paper reports the early performance of 19 19238 KEFRI Headquarters, Kenya 2080 2.8 3.7 49 eight Australian acacias under semi-arid conditions of Mali, 20 19237 Meru, Kenya 1750 2.6 3.7 30 western Africa. Control Kanchanaburi, Thailand 3.0 4.3 71

Grand Mean 3.1 3.9 54

2 Improvement and Culture of Nitrogen Fixing Trees Materials and Methods Table 2. Growth parameters for Acacia species at Samanko (Mali) at age 15 months after outplanting Study site The trial was established in July 2001 at Samanko, 25 km Serial Species name Survival Tree height Tree DBH southwest of Bamako, Mali (12o54'N, 8o04'W; 330 m above No. (%) (m) (cm) 1 A. ataxacantha 89 2.6 3.3 sea level). The site slopes slightly (less than 5%). The average 2 A. colei var. colei 73 4.4 7.2 annual rainfall is 900mm, occurring from June to October. 3 A. colei var. ileocarpa 77 4.0 5.9 The average annual temperature is 27oC. Soils are classified 4 A. coriacea ssp. pendens 3 2.2 5.1 as leached ferruginous tropical soils, sandy-clay-loamy soils 5 A. glaucocaesia 6 3.1 1.9 being derived from schists. They are brown-yellowish in 6 A. mellifera 85 1.4 2.8 7 A. mountfordiae 34 3.1 6.1 colour, deep, well drained and slightly acidic (pH 5.2). The 8 A. trachycarpa 41 0.9 2.1 natural vegetation is the Sahelian parklands with Khaya Mean 51 3.1 4.8 senegalensis, Parkia biglobosa and Vitellaria paradoxa as the LSD 38 0.9 1.7 main species. This study explored the adaptation of the Australian acacias Species sources and details introduced into the Sahelian conditions. The results Eight species of Australian acacias were tested. of two show great potential for A. colei (both varieties) and species, Acacia ataxacantha and A. mellifera were locally A. mountfordiae in the studied conditions. Acacia coriacea collected from Bandia and Bambey Research showed interesting growth but had a very poor survival. Stations, Senegal; while six other species, A. colei var. colei, and goats poorly browse Australian acacias, and most tested A. colei var. ileocarpa, A. coriacea subspecies pendens, species are N-fixers (ICRAF Sahel, unpublished data 2005). A. glaucocaesia, A. mountfordiae and A. trachycarpa, were Their ability to fix atmospheric nitrogen fuels hopes that collected in Australia and supplied by the CSIRO Australian effective by cultivated acacias will enhance Tree Seed Centre. Species details of their provenance the growth of both the acacia and associated crops. These locations are given in Table 1. species could enable rural farmers in the Sahel, where lands are impoverished and where cattle are destroying any newly Table 1. Details of seed source of Australian acacias planted planted and unprotected during the 9-month dry season, at Samanko, Mali. to make better use of the species. They are needed mainly the restoration of the degraded soils, soil fertility improvement, No Species e Seedlot no. Provenance poles, firewood and any other basic products and services 1 A. ataxacantha SN 2001/6613 Bandia, Senegal they may offer. 2 A. colei var. colei CSIRO 14637 E of Hooker Creek, NT*, Australia 3 A. colei var. ileocarpa CSIRO 19992 Rockhole Station, WA*, Australia These identified acacias, together with Acacia tumida, 4 A. coriacea ssp. pendens CSIRO 20300 Weeli Wooli, WA, Australia A. torulosa and A. elachantha, have also been very successful 5 A. glaucocaesia CSIRO 16809 Lajamanu, WA, Australia in Niger (Cunningham and Abasse 2005) under more severe 6 A. mellifera SN 98/6543 Bambey, Senegal climatic conditions. They have the ability to tolerate drought, 7 A. mountfordiae CSIRO 18004 Nabarlek, NT, Australia grow on poor soils and produce high biomass with high 8 A. trachycarpa CSIRO 16774 Mt Lockyer, WA, Australia coppicing ability. They are easy to establish and manage. *) NT: Northern Territory; WA: However there have been reports of serious genetic deterioration due to inbreeding of some species when Experimental design, site preparation and tree planting introduced and managed haphazardly. Randomised complete block design was used with three replicates. Each species was represented once in each block. Therefore, before any scaling-up activities, it is suggested that Each plot consisted of a square plot of 36 plants. Spacing was well designed and managed seed production areas be 2 m x 2 m. Blocks were separated by 3 m. The site was established urgently in the Sahel using a broad genetic manually cleared and then tractor cultivated and deep ripped. germplasm mainly collected from the selected families The site (Samanko Research Station) is fenced to exclude adapted to the Sahelian conditions. It is also proposed that a roaming cattle. Two-month-old seedlings were planted in July synthesis of the research regarding the introduced species in 2001. The experiment was kept weed-free during the first 12 the region be compiled and published, including introductions months (weeded once the first year and twice in the second made in Burkina Faso, Mauritania, Niger and Senegal. The year during the rainy season). report would suggest further research topics for the way forward for a wider utilisation for social environmental and Measurements and data analysis economic benefits provided by Australian acacias to the poor Species were assessed 15 months after outplanting. Data were Sahelian community. recorded at plot level for tree survival, height and tree diameter at breast height. The absence or presence of trees References was recorded at each planting spot and expressed as a Brockwell, J., Searle, S.D., Jeavons, A.C. and Waayers, M. 2005. percentage of those constituting each plot. Differences in each Nitrogen fixation in acacias: an untapped resource for sus- of the assessed parameters were tested using an analysis of tainable plantations, farm forestry and land reclamation. variance (ANOVA) and the LSD (least significant difference ACIAR Monograph No. 115. 132p. Australian Centre for test in SAS. International agricultural Research, Canberra. Cunningham P.J. and Abasse T. 2005. Domestication of Australian Results and Discussion acacias for the Sahelian zone of West Africa. In. Kalinganire, A., Niang A. and Kone, B. (eds.). p.64-74. Domestication des At the age of 15 months species differences were significant espèces agroforestières au Sahel: situation actuelle et per- (P<0.001) for all measured parameters. Results for survival, spectives. ICRAF Working Paper -No. 5. World Agroforestry tree height and diameter at breast height are given in Table 2. Centre: Nairobi. Midgley, S.J. and Turnbull, J.W. 2003. Domestication and use of Australian acacias: case studies of five important species. Australian Systematic Botany 16:89-102.

Improvement and Culture of Nitrogen Fixing Trees 3 Some nitrogen fixing species from Results and Discussion Six nitrogen-fixing species were from the family , a Uttarkashi Valley of Uttaranchal seventh, Hippophae salicifolia, was in the family Elaeagnaceae (non leguminous). This species grows naturally in the Vamunotri area, India Valley and although it had nodules, nitrogenase activity was not determined due to leakage of samples. Nitrogenase activity results S.P. Chaukiyal and T.C. Pokhriyal are given in Table 1. Among the remaining six species Lespedeza Arid Forest Research Institute P.O. Basni New Pali Road, juncea had the highest nitrogenase activity (based of g fresh weight -1 Jodhpur, Rajasthan h ) followed by Crotalaria sessiliflora, Caragana brevispina, India 342005 Lespedeza gerardiana, Indigofera dosua and Vigna vexillata. On Email: [email protected] the basis of plant-1 h-1, maximum nitrogenase activity was recorded in Crotalaria sessiliflora, followed by Lespedeza gerardiana, Lespedeza juncea, Vigna vexillata, Indigofera dosua and Introduction Caragana brevispina. Biological nitrogen fixation occurs possibly in almost all-natural forest ecosystems. The significance of this fact has The variations in the nitrogenase activity, nodule number, been recognized for a number of years, and more recently fresh and dry weight of nodules amongst individual plants has stimulated the utilization of nitrogen fixation as a may be due to heterogeneity in the location and age silvicultural tool. The ways in which N-fixation has been used characteristics. The general low nitrogenase activity for all the in forestry vary greatly. In general, few examples provide species may be due to lower temperatures at higher altitudes evidence for improvement in wood volume growth due to (7500m asl) recorded during 20-24 October 1999. practising biological N-fixation in plantation forestry. The re-cultivation of mine sites or other disturbed habitats is also Table 1. Nitrogen fixing species collected from Uttarkashi an area where N-fixing species find application. Since Valley of Uttaranchal State (India) showing nodule number nitrogen content of such soil is very low it was assumed that and nitrogenase activity most N accumulation of the plants could be attributed to N-fixation. Species Place of Nodules (Pl-1) Nitrogenase activity collection Fresh wt Dry No. g-1 No. Plant-1 h-1 (g) wt fresh There is a great need for the identification of suitable (g) wt h-1 Hippophae salicifolia Jhala, Uttarkashi * * * * * nitrogen-fixing plants, native to the locality, those can thrive Indigofera dosua Jhala, Uttarkashi 0.76 0.65 45 4.2 3.19 well during the process of stabilization and reclamation of Lespedeza gerardiana Sankrona Khal 1.07 0.98 70 5.5 5.88 degraded/eroded sites. Nitrogen-fixing plants can utilize both Lespedeza juncea Sankrona Khal 0.72 0.55 35 8.0 5.76 Caragana brevispina Sankrona Khal 0.52 0.34 30 5.7 2.96 atmospheric as well as soil nitrogen and also improve soil Vigna vexillata Sankrona Khal 0.92 0.71 28 3.6 3.31 physical environment by decreasing the bulk density and Crotalaria sessiliflora Sankrona Khal 0.87 0.65 80 7.2 6.26 increasing moisture retention capacity and thereby benefits * Nodules collected but nitrogenase activity not determined associated vegetation regularly. The nitrogen fixing plants provide a suitable means of biological amelioration of degraded sites. They may serve as a This paper reports results of a survey of nitrogen-fixing plants prelude to introduction of tree species on rocky, barren, from the Uttarkashi Valley of Uttaranchal State, in the severely eroded areas and cliffs, which are very difficult to northwest Garhwal Himalaya for their nodulation and rejuvenate at initial stages. The use of bio-fertilizers in the nitrogen-fixing activity so that these species can be utilized forest management system has not been explored except in reclamation of degraded sites such as mine quarries, where for soil restoration. improving soil organic matter and nutrient content is an obvious need. Nodule development is the summation of a Materials and Methods number of physiological and biochemical processes and the A survey was conducted in theYamnotri and Gangotri valley time for nodule to appear have been used as measure of along the roadside of river Yamuna and Ganga in Garhwal environmental effects on the establishment of (Gibson 1967). However, these species can be utilized for Himalayan region to identify nitrogen-fixing leguminous and conservation purposes in the future programme such as in the non-leguminous herb, shrub, climber and tree species. Most of establishment of ground cover using nitrogen fixing grasses the available leguminous and non-leguminous nitrogen fixing and shrubs in tree planting activities plant species were uprooted to observe the nodulation behaviour. The plants were pressed and mounted on Therefore, there is a great need for the identification and herbarium sheets after proper identification and deposited in screening of effective, efficient and resistant microbial strains the herbarium of the Botany Division, Forest Research from the existing enormous pool of strains, which can easily Institute, Dehradun for future reference. fix atmospheric nitrogen, even under extreme adverse climatic conditions for the maximum benefits of the N-fixing species. The nodules collected were immediately incubated in the glass vials containing 10% acetylene covered with the airtight References lid of rubber serum stopper. After one-hour incubation, these Gibson, A.H. 1967. Physical environment and symbiotic nitrogen samples were kept in an ice kit and brought to plant fixation. IV Factors affecting the early stages of nodulation. Australian Journal of Biological Science 20: 1087-1104. physiology laboratory, Botany Division, Forest Research Pokriyal, T.C., Chaukiyal, S.P. and Naithani, H.B.1993. Nitrogen Institute, Dehradun for the analysis of acetylene reduction fixation and nodulation behaviour of some nitrogen fixing assay in M/S CIC Gas Chromatograph. Pokhriyal et al. (1993) species from inner and outer Himalaya. Indian Forester119 gave the details of the acetylene reduction process. (4): 310-320.

4 Improvement and Culture of Nitrogen Fixing Trees Comparison of wood basic density Materials and Methods and basal area of 5-year-old Acacia Study site Data were collected from both on-station and from farmers' crassicarpa, A. julifera, A. fields. The sites used were: Kipera (1180 m asl), Manoleo/Itonjanda (1250 m asl ), Magiri/Sido (1240 m asl), leptocarpa, Leucaena pallida and Isikizya (1250 m asl) and ARDI-Tumbi (1160 m asl). Soils in the study area are ferric acrisols or Oxic Haplustalfs. They are Senna siamea in rotational woodlots are acidic, low in organic carbon, nitrogen, phosphorus and trials in western Tabora, Tanzania cation exchange capacity. Trials on farmers' fields were farmers managed trials. Farmers were chosen based on their willingness to offer land for the trial and ability to establish Raphael Luhende and conduct all operations in the trials. Tabora Miombo Woodland Research Centre P.O. Box 1960 Tabora, Tanzania Experimental design Email: [email protected] A Complete Randomized Block Design replicated seven times Tel: +255 026 4540 Fax: +255 026 4906 (three times on-station and four times on-farm) where each five plots on-station and each farmer on-farm represented a Gerson Nyadzi replicate. Plot size was 16 m x 20 m (on-station) and had 20 Tumbi Agricultural Research and Development Institute trees. Plot size was 16 m x 16 m, (on-farm) and each plot had P.O. Box 306 Tabora Tanzania 16 trees. Plot spacing was 2 m. Fax: 255 26 260 4907 Email: [email protected] Data collection and analysis Wood samples were selected from small, middle and large Rodgers E. Malimbwi diameter sizes. A total of 84 trees were sampled, 36 trees Sokoine University of Agriculture (on - station) and 48 trees (on - farm trial) 3 trees for each Department of Forest Mensuration and Management species for wood density studies. This is because the method Morogoro, Tanzania is time consuming and destructive. Sampled wood disks of 2 Tel: +255 2604648 cm thickness from each main stem were crosscut at 30%; 60% Email: [email protected] and 90% of the stem length. They were then soaked in distilled water for one week to ensure full cell saturation. The Introduction green volume of each disk sample was measured by water The term rotational woodlot connotes a technology which displacement method. The disks were then oven dried at involves growing trees, normally N-fixing, with crops for 2-3 103±2°C and cooled over silica gel before determining oven years until the trees out-compete the crops. The woodlot may dry weight. then be used as a source of fuelwood, building poles or fodder. Soil fertility is also restored during this time until the Wood basic density was calculated based on oven dry weight farmers can cut the trees and start growing crops between the and green volume as follows: stumps, 4 to 5 years later. The technology was designed to Oven dry weight of disk sample mimic the traditional practice of shifting cultivation by Basic density = introducing trees into the crop and shrub land with shortened Green volume of disk sample fallow. The cropping and fallow phases take place concurrently. This allows the farmers to crop for an extended Basal area studies were done to all surviving trees in a plot by period without returning the land to bush fallow. The measuring tree diameter at breast height (DBH). Mean basal technology is flexible in the sense that it allows the farmers to area per hectare was determined in each plot by using the adopt both the cropping phase and trees to suit individual following formula: needs which diversifies production base, enhances trees and crops productivity and allows a sustainable cropping system G= (Σg i) / a 2 (Ramadhani et al. 2002). Where g i = (π di ) / 4, a and d i are plot area (ha) and Diameter at breast This technology is being promoted by the World Agroforestry height (DBH) of the ith stem in the plot respec Centre (ICRAF) in collaboration with farmers, Tanzania tively Forestry Research Institute (TAFORI), and the Agricultural G = Mean basal area Research and Development Institute (ARDI) Tumbi. The g = basal area per tree main objective is the provision of fuelwood for tobacco curing π = 3.1428 and other domestic uses to rural farmers and improvement of soil fertility in the tobacco-cereal land use system of Tabora, ANOVA was conducted using SAS statistical program. Tanzania. It reduces pressure on the 'miombo' woodlands. Significant difference means were separated at p< 0.001 Despite the potential of this technology, there are few studies according to Zar (1984). An ordinal ranking scheme was used on wood basic density and basal area on trees currently used to separate overall best species. in rotational woodlots. Wood density is highly affected by woodlot manipulation through silvicultural and cultural Results and Discussion practices. This study reports comparison of wood basic density and basal area of 5-year-old N-fixing trees of Acacia Basic density of trees grown in rotational woodlots crassicarpa, A. julifera, A. leptocarpa, Leucaena pallida and Focusing on basic density for trees grown on-station trial, Senna siamea grown in rotational woodlots both on-station Acacia leptocarpa and A. julifera produced higher basic den- and in farmers fields. sities while S. siamea and L. pallida had relatively lower basic density. Differences in basic density between the species were notable for trees grown on-station whereas for trees grown in farmers' fields differences were not significant (Tables 1 and

Improvement and Culture of Nitrogen Fixing Trees 5 2). The basic densities obtained in this study were comparable Productivity of Acacia mangium in to those of A. mangium and A. auriculiformis of 0.570 g cm-3 and 0.617 g cm-3 respectively at the age of six years in Kerala State, India Zanzibar (Ali et al. 1997). The results demonstrate that these species are highly suitable for fuel wood. C. Buvaneswaran and M. George Forest Productivity & Agroforestry Division Table 1. Mean diameter, height, and basic densities of trees Institute of Forest Genetics and Tree Breeding, grown on-station in rotational woodlots. Indian Council of Forestry Research & Education P. B. No.:1061, Forest Campus, Coimbatore - 641 002 Species DBH Height Basic density Basal area Overall rank Tamil Nadu. India (cm) (m) (g cm-3) (m2 ha-1) E-mail: [email protected] A. crassicarpa 15.7a* 10.4 a 0.560 bc 3.54 a 1.25 A. julifera 9.9 b 6.6 b 0.627 ab 2.12 ab 2.00 A. leptocarpa 7.6 bc 6.7 b 0.693 a 1.06 bc 2.25 Introduction S. siamea 7.4 bc 5.9 b 0.507 c 2.32 ab 2.50 Acacia mangium Willd. was introduced into India in 1980s L. pallida 5.16 c 5.6 b 0.550 bc 0.63 c 3.00 *Mean values in the same column with same following letters do not differ significantly and farmers started planting the species on farm fields in the (P > 0.001). early 1990s, particularly in the State of Kerala (Dhamodaran and Chacko 1999). Fast growth and expectations on higher Table 2. Mean diameter, height, and basic densities of trees economic return in short rotation have made this acacia grown on-farm in rotational woodlots. popular for growing on farmlands of Kerala. It is planted both as a sole crop in the form of block plantation as well as Species DBH Height Basic density Basal area Overall rank (cm) (m) (g cm-3) (m2 ha-1) introduced as a component in homesteads. This paper A. crassicarpa 15.3a 9.4 a 0.584 a 4.67 a 0.25 describes its performance and productivity under different A. julifera 8.1 b 6.6 b 0.622 a 3.97 a 1.50 planting conditions on farm fields in various agro-climatic A. leptocarpa 7.8 b 6.9 b 0.647 a 1.98 a 1.50 zones of Kerala. S. siamea 7.0 b 5.9 bc 0.540 a 4.36 a 1.75 L. pallida 4.0 b 4.6 c 0.444 a 1.18 a 2.00 Materials and Methods * Mean values in the same column with same following letters do not differ significantly The study was conducted in the state of Kerala. Altitude (P > 0.001) varies from sea level in the coastal plain to 2694 m at Anamudi. Mean annual rainfall varies from 2000 to 3200mm Mean basal area for trees grown in rotational woodlots Differences in basal area were outstanding for trees grown in most of the areas. The soils are either shallow-medium on-station. Trees on farmers' fields trial were uniform in basal depth, loamy, red and lateritic or deep coastal alluvials. Kerala area production. Acacia crassicarpa and A. julifera had the is divided into eight agro-climatic zones and A. mangium is highest basal area respectively in both trials followed by grown mainly in three zones viz. Northern, Southern and High S. siamea (Tables 1 and 2). Altitude zones both in homesteads and in plantations.

Mean diameter and height growth for trees grown in Most of the A. mangium plantations on farmlands are 6-10 rotational woodlots years old. Spacing is between 2.5 x 2.5 and 3 x 3m in block Differences in diameter between the species are important for plantations and varies widely in homesteads. trees grown on-station compared to those from farmers' fields. Acacia crassicarpa was the tallest species and L. pallida the Results and Discussion shortest. Other species exhibited uniformity in height growth in both trials which suggest little contribution to basal area in both sites. The growth of Acacia mangium on farmlands is shown in Table 1. Conclusion The higher basic density of wood for nitrogen fixing trees Table 1. Mean growth performance of Acacia mangium at grown in rotational woodlots in Tabora suggests suitability of different ages in Kerala. these species for fuelwood purposes. The trees can be good source of fuel for curing tobacco in the tobacco cereal land use Age (years) Girth (cm) Height (m) system. It is recommended that long-term observation studies 4 46.0 12.0 on wood basic density be done in rotational woodlots in order 5 57.7 12.0 to understand the effects of different management. It is also 6 61.1 13.0 noted that among the species tested A. crassicarpa has the 7 63.0 13.0 greatest wood yield. 8 81.2 15.0 References Ali, M.S., Malimbwi, R.E. and Iddi, S. 1997. Comparison of volume The mean annual increment (MAI) in terms of girth at breast production, basic density and stem quality between height was calculated for three zones in Kerala. Plantations in A. mangium and A. auriculiformis grown in Zanzibar. the High Altitude zone had the highest MAI (9.6 cm) compared Journal of Tropical Forest Science 10: 10-17. to 8.0 cm and 9.3 cm in the Southern and Northern zones Ramadhani, T., Otsyina, R. and Franzel, S. 2002. Improving respectively. household incomes and reducing deforestation using rotational woodlots in Tabora district, Tanzania. Agriculture, This study confirms that growth performance of A. mangium Ecosystems and Environment 89: 229 - 239. varies greatly with site conditions. The productivity of Zar, J.H. 1984. Biostatistical analysis. Prentice Hall, Englewood A. mangium was 35-45 m3 ha-1 yr-1 in humid zones, particularly Cliffs, New Jersey. 2nd edition. 718 p. in the Southern zone, and from 20-25 m3 ha-1 yr-1 in subhumid

6 Improvement and Culture of Nitrogen Fixing Trees

belt of the Northern zone. Acacia mangium is grown mostly as to collect fine roots data. The data were analyzed using the an intercrop in homesteads and is preferred for vanilla and statistical analysis systems (SAS). pepper crops. The introduction of superior provenances of the species with resistance to heart rot/root rot diseases would Results and Discussion encourage farmers of Kerala to use it on their farms. Root length densities varied considerably among the References treatments with the lowest density occurring in the Dhamodaran, T.K. and Chacko, K.C. 1999. Growth and wood Pterocarpus santalinoides treatment (Table 1). From tree-crop characteristics of Acacia mangium grown in Kerala. KFRI interaction standpoint, this low root density of E. cyclocarpum Research Report No. 174. Kerala Forest Research Institute, is important because the species will not compete with Peechi, Kerala, India. agricultural crops in agroforestry systems. Pterocarpus santalinoides was the most shallow-rooted species and its fine roots extended only to 40cm soil depth. As expected, the highest root density was recorded for edulis. Roots of I. Root Length Density of Leguminous edulis were found at the 90cm soil depth, and Inga was the Agroforestry Tree Fodders in Niger most deep-rooted species. Inga edulis is a fast-growing species attaining 3 m in height growth on acid soils in 3 years. Delta Region of Nigeria This may explain its greatest root length density. Based on previous report, Anegbeh et al. (2004) concluded that I. edulis Paul O. Anegbeh was a valuable agroforestry tree legume for fodder. World Agroforestry Centre (ICRAF) Irrespective of the woody species, the root density was International Institute of Tropical Agriculture (IITA) greatest at the 40-100 cm lateral distance from tree base, IITA High Rainfall Station, Onne, PMB 008, Nchia-Eleme, suggesting wide inter-row spacing (≥ 10 m) of the species. Port Harcourt, Rivers State, Nigeria This also suggests that the inter-crops (agricultural crops) in Tel: 234-2-241 2626 ext. 2399 Fax: 234-2-241 2221, agroforestry systems should be arranged starting from 2-3 m Email [email protected] away from tree base to minimize negative interactions from woody species (Haggar and Beer 1993). In simultaneous Introduction agroforestry systems, desirable trees, preferably legumes, are Interactions between trees and crops for below-ground deliberately integrated with food crops so that the tree and resources are often as important as those for above-ground crop components mutually maximize sharing of resource resources. Therefore, identification of suitable woody species pool. The root length densities of all the species decreased for agroforestry systems is one of the most important with soil depth. With appropriate design and management in challenges of agroforestry. The few studies that have agroforestry systems, the studied species may help meet the attempted to evaluate woody species for farming systems in needs of rural farmers for soil fertility improvement, crop and the Niger Delta Region of Nigeria have focused on Leucaena fodder production. The results of this study support the need leucocephala and Gliricidia sepium, but these two species for selection and use of desirable woody legumes for fodder have been found to perform poorly on acid soils regarding and sustainable agroforestry systems in the Niger Delta root distribution patterns and above-ground biomass Region of Nigeria. production. Evaluation and selection of leguminous fodder -3 species for agroforestry systems depend largely on an Table 1. Root length density (cm cm ) of fine roots* of three understanding of root distribution patterns of such species agroforestry tree legumes grown on acid soils in the Niger (Anegbeh and Tchoundjeu 2005). This is particularly delta region of Nigeria (3 years after planting) important in Niger Delta Region where agroforestry systems, which are ecologically compatible, environmentally Lateral distance E. cyclocarpum I. edulis P. santalinoides sustainable, and commercially viable, are promoted. The from tree base (cm) objective of this study was to examine quantitatively the root 40-50 30.2 83.3 96.9 length densities of three leguminous tree fodders for 50-60 38.0 67.8 29.7 agroforestry systems in the Niger Delta Region of Nigeria. 60-70 35.5 68.5 33.6 Materials and Methods 70-80 30.3 70.5 21.4 The experiment was conducted from 1994 to 1997 at the High 80-90 53.2 32.1 17.3 Rainfall Station of the International Institute of Tropical 90-100 34.2 34.0 39.3 Agriculture (IITA) Onne in the Niger Delta Region of Nigeria 100-110 26.2 92.9 69.9 (4o51' N latitude 07o03' E longitude, 30m altitude). The soils 110-120 45.4 92.0 98.6 are acidic (pH 4.4). Seeds of cyclocarpum 120-130 25.5 42.7 44.6 (Jacq.) Griseb, Inga edulis Mart., and Pterocarpus 130-140 44.1 35.6 43.2 santalinoides L'Her. Ex DC were collected from Agodi 140-150 35.4 34.7 59.7 Botanic Garden (Ibadan), IITA Onne (Port Harcourt), and *(< 2 mm in diameter) Ughelli (Warri) respectively. Seedlings were raised, hardened, and established as hedgerows in 1994. Treatments were arranged in a Completely Randomised Design with three Conclusion replications using a spacing of 4.0 m x 0.25 m. Three-year-old This study shows the agroforestry potential of Enterolobium trees were used for the root studies. A pin-board method cyclocarpum, Inga edulis, and Pterocarpus santalinoides. described by Anegbeh and Tchoundjeu (2005) was used These leguminous species, which are also valued for fodder,

Improvement and Culture of Nitrogen Fixing Trees 7 are recommended to rural farmers in the Niger Delta Region What does this mean? Nothing will change until formal of Nigeria for use in agroforestry systems to maximize proposals to split the genus Acacia have been published. benefits from farming systems. When this happens, it is expected that the generic names will be: Acacia for species currently in subgenus Phyllodineae; References Vachellia for species in the present subgenus Acacia; and Anegbeh P.O. and Tchoundjeu, Z. 2005. Root distribution of two Senegalia for most species in subgenus Aculeiferum. About agroforestry tree legumes suitable for fodder production in 30 species from the currently in subgenus Niger Delta Region, Nigeria. NFT News 8 (1) 4-5. Aculeiferum will be included in two new genera. There will Anegbeh, P.O., Tchoundjeu, Z., Amakiri, M.A., Wahua, T.A.T., Opuwaribo, E.E. and Ujor, G. 2004. Chemical composition still be name changes to some very important species and, and nutritive value of foliage of Inga edulis Mart, an while this will be inconvenient for some, the overall agroforestry tree legume for fodder. International Journal of disruption will be less than it might have been. Science and Technology 3 (2): 30-33. Haggar, J. P. and Beer, J. W. 1993. Effect of maize growth on the Most of the information above has been taken from a more interaction between increased nitrogen availability and competition with trees in alley cropping. Agroforestry detailed account by Bruce Maslin and Tony Orchard. Systems 21: 239-250. This can be consulted on the following website: www. worldwidewattle.com/infogallery/nameissue/decision.php

Acacia Naming Decision

John W. Turnbull PO Box 5034 Garran, ACT 2605 Australia [email protected]

Introduction Name changes for the large genus Acacia have been pending for a number of years. In the last issue of this newsletter it was noted that the genus was likely to be divided into at least five genera and that under the normal rules of botanical nomenclature most species of economic importance would require a name change. A final decision on how to proceed was made at the International Botanical Congress in Vienna in July 2005.

Until recently, Acacia was accepted as one genus of almost 1400 species. These species were distributed throughout the tropics and especially in Australia. Studies have now shown that species in the genus comprise three main groups, with two other smaller groups in Central America. Almost all the Australian species fall into one group of about 1000 species. Some species of this group extend to the islands of the Pacific, to Southeast Asia and to Madagascar. Most of the remaining 380 species make up two more or less equal groups that predominate in the Americas, tropical and southern Africa and tropical Asia.

The Committee for Spermatophyta of the International Association for Plant (IAPT) recommended retypification of Acacia so that the largest group (subgenus Phyllodineae) would not require name changes. The Committee's opinion was based on the wish to reduce nomenclatural change and inconvenience to a minimum. This recommendation was endorsed by the IAPT General Committee and passed to the Nomenclature Section of the International Botanical Congress in Vienna. A move to overturn the Committee's decision and retain the African species as type was narrowly defeated. The decision had finally been made!

8 Improvement and Culture of Nitrogen Fixing Trees Guidelines for Contributions Editorial Board

We encourage members of the NFT Working Party to share their experiences and research results with others. Please help to make this Coordinator: Dr Antoine Kalinganire newsletter and the NFT Working Party successful World Agroforestry Centre by sending articles on relevant topics to us. ICRAF West and Central Africa Content: IUFRO WP news, conference reports, BP 320 Bamako, Mali new books, brief review or technical articles, Tel: +223 222 3375; Fax: + 223 222 8683 letters or comments related to improvement and Email: [email protected] culture of nitrogen fixing trees. Language: The newsletter will be published only in English at present. All submissions should be Deputy Coordinators: Mr Vitoon Luangviriyasaeng presented in English. Silviculture Research Group Royal Forest Department Text format: All submissions may be sent by email or in print with a copy in Word file. 61 Paholyothin Rd, Chatuchak Typescripts or disks will not be returned unless Bangkok 10900, Thailand indicated. Email: [email protected]

Figures: Submit accompanying graphs, tables Dr Ousman Diagne charts, etc and captions in printed, camera-ready or high-resolution electronic form. Very good Centre National de Recherches Forestières quality slides and photographs will be accepted. Institut Sénégalais de Recherches Agronomiques Dakar, Senegal Submissions: Please address submissions to the Email: [email protected] WP Coordinator or Deputy Coordinators, their respective addresses are indicated in this newsletter. Founding Editor: Mr Khongsak Pinyopusarerk, Canberra, Australia The newsletter will be available from the IUFRO website and in print depending on funds availability. Editors: Dr Antoine Kalinganire, Bamako, Mali Mr Vitoon Luangviriasaeng, Bangkok, Thailand Ms Annonciata Uwamariya, Bamako, Mali

Advisors: Dr Bokary Kaya, Ségou, Mali Dr John Turnbull, Canberra, Australia

Design Mr Vlad Mosmondor, Canberra, Australia Email: Mosmondesign@ netspeed.com.au WWW.home.netspeed.com.au/mosmondesign

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Improvement and Culture of Nitrogen Fixing Trees 9