Green manure of multipurpose trees is known to be a good source of nutrients to cropHowever, most agroforestry species do not have adequate phosphorus (P) in their leaves. Supplementing green manure with moderate dose of P is a beneficial strategy to improve food security in Rwanda. This study examines the effects of Calliandra calothyrsus Meissner, Tithonia diversifolia Hensley A.Gray and Tephrosia vogelii Hook.f. green manure applied independently or in combination with triple super phosphate (TSP) and lime on maize yield and P uptake in the Oxic Tropudalf of Rubona, Rwanda. The treatmentswere the control, lime at 2.5 t ha-1,TSP at 25 and 50 kg P ha-1, leafofC. calothyrsus, T. diversifolia, and T. vogelii each at 25 and 50 kg P ha-1, respectively. Leaf shrubs biomass,TSPand limewere applied for four consecutive seasons (2001-2004). The results showed that the combination of greenmanure with TSP at a rate of 50 kg P ha-1 significantly increased maize yield from 24 to 508% when compared to the control and T. divesifolia combined with TSP was leading (508%). Equally, the same treatments as indicated above showed higher P uptake (15.6-18. 6 kg P ha-1) than the control (5 kg P ha-1) and 65% of maize yields variation was explained by total P uptake. The plant residues quality such as C:N ratio, total plant N, and P significantly Calliandra calothyrsusinfluenced the variability of maize grain yields.
Tag: calliandra calothyrsus
Biomass production and root distribution of eight trees and their potential for hedgerow intercropping on an ultisol in Southern Sumatra
The results are reported of 2 experiments with exotic and local tree species, in order to assess their suitability for alley cropping on an acid soil, and as part of a nitrogen management project carried out in Lampung. The first experiment was an alley cropping trial established in 1986 and 1987 on a site cleared of secondary forest in 1986. The hedgerow species tested were Calliandra calothyrsus, Gliricidia sepium, Leucaena leucocephala, Peltophorum pterocarpa [P. pterocarpum] and Erythrina orientalis, with Mucuna pruriens var. utilis used initially as a leguminous cover crop. Tree spacing was 4 m between rows and 0.5 m within rows. Regular pruning and intercropping with food crops started in 1988. The trees were pruned every 4 months to 1 m height for 3 consecutive growing seasons (forming a hedge 40 cm wide), and thereafter the regime was adapted according to the crop. Dry weight production and N yield of prunings (which were added to the soil) was recorded, and differences in canopy shape and root distribution between the species (and their potential effects on crops) discussed. C. calothyrsus produced the most biomass, and E. orientalis the least. The second experiment examined the effect of stem pruning height and root pruning on 6 leguminous tree species (Calliandra calothyrsus, Cassia siamea, E. orientalis, Peltophorum pterocarpum, G. sepium and Albizia falcataria) and one non-legume (Peronema canescens). The trees were planted in February 1988 on a plot recently cleared of forest vegetation in rows 2 m apart, and with an inter-row spacing of 0.5 m. Root pruning was done in December 1988 (and annually thereafter) by digging a 20-cm deep trench 50 cm from the tree row. Pruning heights of 50, 75 and 100 cm were tested at 4-8 month intervals. Observations were recorded on biomass production at pruning, canopy shape, specific leaf area, light interception at ground level and root distribution, dry weight, density and nodulation. Lower pruning heights led to less biomass production and an increase in the number of branch roots originating from the stem base. A. falcataria and Peronema canescens did not tolerate regular pruning well. Consistent effects were not demonstrated of root pruning on biomass production in relation to stem pruning. Overall, the results demonstrate that the most suitable species for alley cropping on this acid soil is the relatively deep rooted Peltophorum pterocarpum; otherwise alternating hedgerows of P. pterocarpum and G. sepium are suggested as suitable. P. pterocarpum formed the densest canopy in a small hedge volume when pruned in a 3-month-cycle. Calliandra calothyrsus produced more biomass and supplied more nitrogen than any other species but would need more regular pruning to avoid shading intercrops; this could be compensated for by growing the trees at greater inter-row distances. The other species tested were all less suitable for alley cropping.
Adoption potential of rotational hedgerow intercropping in the humid lowlands of Cameroon
Shifting cultivation in the humid lowlands of Cameroon has been associated with declining soil fertility resultingin low yields of food and tree crops. Agroforestry and improved fallow systems such as hedgerow intercropping canplay an important role in improving sustainable production on farmers’ fields. Between 1988 and 1993 theInternational Centre for Research in Agroforestry Humid Lowlands of West Africa Programme (ICRAF-HULWA) inCameroon evaluated the conventional hedgerow intercropping and, more recently (1994–8), rotational hedgerowsystems. Farmer adoption has remained low. Based on continued monitoring of on-farm trials and a socioeconomicsurvey, three main reasons why farmers do not easily adopt the innovation were identified. Firstly, contrary toexpectations, farmers indicated that land availability is not a problem and that they can acquire more land in thevillage if there is a need. Secondly, in the lowlands of Cameroon, soil erosion is not a major concern of farmers.Thirdly, farmers in the study zone do not feel that soil fertility is a major problem and are thus hesitant to invest infertility management. Furthermore, farmers seem to be concerned about issues such as lack of marketing opportunitiesand shortage of cash to pay for health care and education, rather than the decline in soil fertility. However, recentexperience with more flexible design and management of hedgerow intercropping and more targeted promotion ofthe technology has shown a growing interest of farmers to plant tree fallows. Consequently, further research shouldfocus on diversification of the output of rotational hedgerow systems. The promotion of rotational hedgerow systemsshould target sites where farmers perceive land shortage and poor soils to be major problems
AFRENA project Burundi: progress report for the period November 1988 to February 1990
At the end of 1986, ICRAF launched an agroforestry research network. for the highlands of East and Central Africa with USAID funds. The network is part of ICRAF’s AFRENA programme, which encompasses three other ecological zones in subsaharan Africa. The 2 main objectives of the AFRENA programme are: 1. To develop appropriate agroforestry technologies for land use systems within an ecological zone, and 2. To develop national/regional capacity to plan, formulate and implement agroforestry research
Agronomic and economic evaluation of organic and inorganic sources of phosphorus in Western Kenya
Manys oils in the highlands of East and Central Africa are depleted of soil nutrients, particularly P. Ouro bjective was to comparec attle manure, Calliandra calothyrsus Meissner leaf biomass, and triple superphosphule (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 ha1 for application of urea without P. Application of 10 kg P ha1 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 bole (293 USD ha1), broadcast manure (255 USD ha1), and broadcast TSP + 44 kg urea-N ha1 (313 USD ha1 at P = 30 kg ha1 and 98 USD ha1 at P = 10 kg ha1). Net benefits for calliandra leaf biomass were highest (136 USD ha1) 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. Cailiandra 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.
Nutrient intake and utilisation by goats fed dried leaves of the shrub legumes Acacia angustissima, Calliandra calothyrsus and Leucaena leucocephala as supplements to native pasture hay
Thirty-six indigenous goats were used to determine the potential of sun-dried leaves of the shrub legumes Acacia angustissima, Calliandra calothyrsus and Leucaena leucocephala as supplements to native pasture hay (NPH). The dried leaves were included at the rates of 80, 160 and 320 g/head/day. Cottonseed meal fed at the same levels, and NPH fed alone were included as controls. Among the browses, C. calothyrsus had the lowest N content of 19.0 g/kg dry matter (DM) and A. angustissima the highest of 35.0 g/kg DM. The leaves from the legumes had significantly less N and higher cell wall, neutral detergent insoluble N (NDIN) and acid detergent insoluble N (ADIN) contents than cottonseed meal. The values of NDIN as a fraction of total N were 19, 456, 526 and 816 g/kg for cottonseed meal, L. leucocephala, A. angustissima and C. calothyrsus, respectively.Proanthocyanidin contents were 33, 196 and 134 g/kg DM for A. angustissima, C. calothyrsus and L. leucocephala, respectively. Type of supplement did not affect (P>0.05) NPH, total and digestible DM intakes although NPH intake was depressed (P<0.05) at the highest level of supplementation compared to the first two levels. Animals fed legumes excreted significantly more (P<0.001) faecal N (g/kg N intake) than animals consuming cottonseed meal. The reverse was observed for urine N. Among the legumes, C. calothyrsus had significantly higher (P<0.001) N in faeces (958 g/kg N intake) than A. angustissima (630) and L. leucocephala (615). Significant (P<0.05) correlation coefficients were obtained between proanthocyanidins (PAs) intake and faecal N, NDIN and ADIN (0.535, 0.501 and 0.786, respectively). Regressing digestible N on N intake indicated that A. angustissima and C. calothyrsus tannins had significant effects on the digestion of dietary N. The animal responses were discussed in relation to PAs content. It was concluded that both the type and level of PAs were important determinants of the animal responses.
Optimum plant density and harvest age for maximizing productivity and minimizing competition in a Calliandra short-rotation-coppice plantation in West Java, Indonesia
To produce large volumes of biomass for implementing its green energy policy, the Government of Indonesia has issued a short rotation energy plantation program for a number of tree species including Calliandra calothyrsus (Meissn.). Optimum density and prompt harvesting are needed to maximise productivity, but information regarding both factors is insufficient. This study aimed to investigate the optimum growth spacing and ideal felling age to produce the largest volumes of biomass both economically and sustainably. Experiments were arranged on one hectare of land, which was divided into four plots with different plant spacing treatments (1 × 1.5 m; 1.5 × 1.5 m; 2 × 1.5 m; and 2 × 2 m). Growth and yield observations were carried out on plants aged 12, 18, and 24 months in each plot, with 30 sample trees left for growth observations and ten sample trees cut at each of the three ages after planting. This resulted in a total of 240 samples from the 2,710 trees planted. Trees were felled at 50 cm from the soil surface, and the resulting stools were left to regrow. A year after felling, resulting coppices, were observed and cut. Growth, productivity and calorific value were studied for both ‘primary’ and ‘coppiced’ wood. Study results demonstrate that competition between plants strongly determines the growth and productivity of ‘primary’ wood. The plot with the densest plant spacing had the lowest nutrient content for almost all soil nutrients. Higher plant density showed higher competition index values, and resulted in fewer and smaller diameter stems emerging from stools, and lower biomass productivity. Competition index values, which increased with plant age, can be used as an indicator for determining harvest timing. Productivity increased by up to 15% following development as a coppice plantation. Optimum wood productivity and greatest economy came from parent stands with plant spacing of 2 × 2 m, harvested at 18 months old and coppiced. This treatment yielded an average biomass/tree of primary wood 7.2 kg and coppice wood 8.22 kg, respectively, with lignin content of approximately 22%, and calorific value of around 18,807 kJ. These values match biomass energy requirements for feedstock for electricity generation. Harvesting at 24 months showed no significant increases in productivity, lignin content, or calorific value.