The commonly practiced ground-level planting was compared with a moisture-conserving open-pit sunken planting technique in an attempt to test the success of modified planting techniques that enhance tree survival and early growth in arid environments. An indigenous species, Acacia mellifera (Vahl.) Benth., which is well adapted to the environmental conditions of the trial site, was used for the comparative study. Trial results showed that, after 21 months, height growth of seedlings planted in open pits was almost three times faster than that of seedlings planted at ground level. Total biomass production of open pit planted seedlings exceeded that of those planted at ground level by 78%. Shoot ÷ root ratios of biomass produced were 1 ÷ 1.07 in sunken plantings and 1 ÷ 1.43 in level planting, suggesting that roots of sunken planted seedlings support a higher above-ground biomass production. No mortalities occured in either of the two treatments because of the natural drought tolerance of A. mellifera. The highly significant differences in height growth performance suggested that this planting technique should be tested on other tree species on a larger scale. Accordingly, Leucaena leucocephala (Lam.) de Wit was used for a second, larger experiment. The results of this trial largely confirmed those of the preceding one. After 31 months, the increase in shoot length of seedlings planted in open pits was 50% higher than that of seedlings planted at ground level. However, total biomass production was only 13% higher for seedlings planted in open pits and no significant differences between the two treatments could be established. Nevertheless, there was a significant difference between the species’ shoot-to-root ratios. This ratio was 1 ÷ 1.04, for the sunken planting treatment, compared to 1 ÷ 1.60 for level planting. Mortality among seedlings in the open pits was half that of the seedlings planted at ground level.
Tag: leucaena leucocephala
Leucaena leucocephala leaf meal as supplement to diet of grazing dairy cattle in semiarid Western Tanzania
The effect of supplementation with three levels of Leucaena leucocephala leaf meal (LLM) added to a diet composed of cotton seed hulls (CSH) and maize bran (MB) on milk yield, milk composition and body weight changes of grazing lactating cows was studied in a completely randomised design. Marginal product analysis for the different levels of LLM as a substitute to cotton seed cake (CSC) was also calculated. The following treatment diets were used in the experiment: Diet 1, (control) composed of 1.8 kg DM CSH and 1.8 kg DM MB. Diet 2, 3 and 4 had an addition of 1.2, 2.0 and 2.6 kg DM of LLM respectively. Diet 5 was composed of 1.8 kg DM of CSC and 1.8 kg DM of MB. Treatments, number of lactations, farm and initial milk yields significantly (P 0.05). Cows on treatment 1 achieved no significant (P 0.05) difference in net milk produced by cows on treatment 2, 3 and 5 compared to treatment 1. LLM supplementation significantly (P 0.05) influence on milk crude protein (CP), butter fat (BF), solids not fat (SNF) and ash in all the diets. Body weight was significantly (P < 0.05) increased by LLM supplementation. Degradation coefficients of the treatment diets were high and varied significantly (P < 0.01) and had an influence on the metabolizable energy value of the treatment diets. Cows on diet 2 to 4 had a weight gain of 190.9, 101.8 and 80.9 g/cow/day respectively and cows on diet 5 attained the highest weight gain (234.5 g/cow/day). Diet 4 had the highest marginal productivity of 4.3 followed by diets 2, 3 and 1 with marginal productivities of 2.8, 0.6 and 0 respectively. It was therefore, concluded that the optimal supplementation level using LLM as a substitute for the more expensive CSC was diet 4.
Multipurposes tree prunings as a source of nitrogen to maize under semiarid conditions in Zimbabwe. 2. Nitrogen-recovery rates and crop growth as influenced by mixtures and prunings
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.
Multipurpose tree prunings as a source of nitrogen to maize under semiarid conditions in Zimbabwe. 1. Nitrogen-recovery rates in relation to pruning quality and method of application
Decomposition- and N-mineralization rates of multipurpose tree prunings applied as a source of N to annual crops in agroforestry systems are affected by the chemical composition and method and time of application of the prunings and the soil type. In a greenhouse study undertaken on two contrasting Zimbabwean soils, there was a significant interaction of pruning quality with time and method of pruning application on nitrogen recovery by maize and residual effects on a subsequent maize crop on both soil types. Incorporating prunings in the soil at planting gave higher nitrogen recovery compared to surface application at two or four weeks after planting for all three MPT species used.Flemingia macrophylla showed prolonged N immobilization on an Alfisol (sandy clay loam) but not on the Psamment (sandy soil). Nitrogen recovery by the second maize crop (residual effect) was influenced by pruning quality, time of application, and soil type. Low-quality prunings such asFlemingia macrophylla andAcacia angustissima applied four weeks after planting gave higher residual effect on N recovery on the Alfisol than on the Psamment (3% vs. 6%).
Agrosilvicultural systems: an alternative for the integrated management of mountainous terrain in Cuba.
The paper presents some Cuban experience on the research and development of agroforestry systems under mountainous conditions. The results obtained indicate that food fodder and wood can be realised on terraces of gradients between 5 and 40 percent. The livestock component indicated the posibility of utilizing the pastures that develop as the forest component is established.
Biomass equations for tropical tree plantation species using secondary data from the Philippines
Estimation of the magnitude of sinks and source s of carbon requires reliable estimates of the biomass of forests and of individual trees. Equations for predicting tree biomass have been developed using secondary data involving destructive sampling in plantations in several localities in the Philippines. These equations allow estimates of carbon sequestration to be made at much lower cost than would be incurred if detailed stand inventories were undertaken. The species included in the study reported here include Gmelina arborea, Paraserianthes falcataria, Swietenia macrophylla and Dipterocarp species in Mindanao;Leucaena leucocephala from Laguna, Antique, Cebu, Iloilo, Rizal, and Ilocos Sur, and Acacia mangium, Acacia auriculifor mis and G. arborea in Leyte. Non-linear regression was used to derive species-specific, site-specific and generic equations between yield and diameter of the form y = aDb . Equations were evaluated based on the correlation co efficient, standard error of the estimate and residual plots. Regressions result ed to high r values (>0.90). In some cases, non-homogeneous variance was encountered. The generic equation improved estimates compared with models used in previous studies.
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
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.