Showing papers in "Agroforestry Systems in 2007"
TL;DR: In this paper, the authors compared the diversity in the Indonesian jungle rubber agroforestry system compared to that in primary forest and rubber plantations by integrating new and existing data from a lowland rain forest area in Sumatra.
Abstract: Plant and bird diversity in the Indonesian jungle rubber agroforestry system was compared to that in primary forest and rubber plantations by integrating new and existing data from a lowland rain forest area in Sumatra. Jungle rubber gardens are low-input rubber (Hevea brasiliensis) agroforests that structurally resemble secondary forest and in which wild species are tolerated by the farmer. As primary forests have almost completely disappeared from the lowlands of the Sumatra peneplain, our aim was to assess the contribution of jungle rubber as a land use type to the conservation of plant and bird species, especially those that are associated with the forest interior of primary and old secondary forest. Species-accumulation curves were compiled for terrestrial and epiphytic pteridophytes, trees and birds, and for subsets of 'forest species' of terrestrial pteridophytes and birds. Comparing jungle rubber and primary forest, groups differed in relative species richness patterns. Species richness in jungle rubber was slightly higher (terrestrial pteridophytes), similar (birds) or lower (epiphytic pteridophytes, trees, vascular plants as a whole) than in primary forest. For subsets of 'forest species' of terrestrial pteridophytes and birds, species richness in jungle rubber was lower than in primary forest. For all groups, species richness in jungle rubber was generally higher than in rubber plantations. Although species conservation in jungle rubber is limited by management practices and by a slash-and-burn cycle for replanting of about 40 years, this forest-like land use does support species diversity in an impoverished landscape increasingly dominated by monoculture plantations.
145 citations
TL;DR: In this paper, the authors evaluated five agricultural (four agroforestry and one conventional) systems in order to test the hypothesis that the agro-forestry systems promote an increase in the soil organic carbon stocks and organic carbon pools, thus improving soil quality.
Abstract: Many environmental benefits have been attributed to agroforestry systems in various ecosystems around the world. However, there is a limited amount of information to evaluate this agricultural system in the semi-arid region, specifically in the region of Ceara, Brazil. The objective of this work was to evaluate five agricultural (four agroforestry and one conventional) systems in order to test the hypothesis that the agroforestry systems promote an increase in the soil organic carbon stocks and organic carbon pools, thus improving soil quality. The following treatments were tested: agrosilvopasture (AGP), silvopasture (SILV), traditional agroforestry (TRAG), intensive cropping (IC), and native forest (NF). The soil samples were collected at four depths: 0–6, 6–12, 12–20 and 20–40 cm. Total soil organic carbon stocks and the organic carbon pools (microbial biomass-C, mineralizable-C, oxidizable-C, free, occluded light fraction organic matter, and C in the humic substances) were analyzed. After 5 years of experimental cultivation, the soil under the SILV system presented the best results for the attributes studied, preserving, and in some cases, improving these attributes, when compared to the other conditions. The traditional agroforestry system (TRAG) reduced total organic carbon stocks and, consequently, C in some organic matter compartments, indicating that the fallow period was not sufficient to maintain soil quality. The AGP and IC systems presented significant losses in some of the soil organic matter (SOM) pools, suggesting that the soil environment had been degraded. The most labile SOM components were considered sensitive indicators of change in the soil quality. The silvopasture system can, therefore, be recommended as an alternative soil management strategy for food production and for the maintenance of soil quality and agricultural sustainability in the semiarid region of Ceara state.
127 citations
TL;DR: Trees benefited from the crop or pasture management: trees featured a significantly improved nutritional and physiological status, a faster growth and a higher fruit productivity than trees growing in encroached or forest plots.
Abstract: Dehesas are extant multi-purpose agroforestry systems that consist of a mosaic of widely-spaced scattered oaks (Quercus ilex L.) combined with crops, pasture or shrubs. We aimed to clarify the role of trees in dehesas of CW Spain focussed on the analysis of tree-understorey interactions. Spatial variability of resources (light, soil moisture and fertility), microclimate, fine roots of both herbaceous plants and trees and forage yield was measured. Additionally, we compared the nutritional and physiological status, growth and acorn production of oaks in cropped (fodder crop), grazed (native grasses) and encroached (woody understorey) dehesa plots. Significant light interception by trees was limited to the close vicinity of the trees, with very low reduction away from them. Both microclimate and soil fertility improved significantly in the trees vicinity, irrespective of soil management. Soil moisture varied very few with distance from the trees, as a result of the extended root system of oaks. Root systems of trees and herbs did not overlap to a great extent. Crop production was higher beneath trees than beyond the trees in unfertilised plots and foliar nutrient content of oaks did not increase significantly with crop fertilisation, indicating that trees and crops hardly compete for nutrients. Moreover, trees benefited from the crop or pasture management: trees featured a significantly improved nutritional and physiological status, a faster growth and a higher fruit productivity than trees growing in encroached or forest plots.
120 citations
TL;DR: In this article, the authors investigated the effects of different soil-incorporated organic (manure, Tithonia diversifolia, Calliandra calothyrsus, Leucaena leucocephala) and mineral fertilizer inputs on maize yield, and soil chemical properties over seven seasons.
Abstract: Soil nutrient depletion as a result of continuous cultivation of soils without adequate addition of external inputs is a major challenge in the highlands of Kenya. An experiment was set up in Meru South District, Kenya in 2000 to investigate the effects of different soil-incorporated organic (manure, Tithonia diversifolia, Calliandra calothyrsus, Leucaena leucocephala) and mineral fertilizer inputs on maize yield, and soil chemical properties over seven seasons. On average, tithonia treatments (with or without half recommended rate of mineral fertilizer) gave the highest grain yield (5.5 and 5.4 Mg ha−1 respectively) while the control treatment gave the lowest yield (1.5 Mg ha−1). After 2 years of trial implementation, total soil carbon and nitrogen contents were improved with the application of organic residues, and manure in particular improved soil calcium content. Results of the economic analysis indicated that on average across the seven seasons, tithonia with half recommended rate of mineral fertilizer treatment recorded the highest net benefit (USD 787 ha−1) while the control recorded the lowest (USD 272 ha−1). However, returns to labor or benefit-cost ratios were in most cases not significantly improved when organic materials were used.
115 citations
TL;DR: In this article, the effects of livestock grazing on plants and soils in pastures and forests were investigated, and the effects were quickly reversed following cessation of grazing and had little detrimental effect on silvopasture forage or tree production.
Abstract: Livestock, pasture, and timber trees are intimately interrelated in silvopastures. Most silvopasture research to date has focused on forage/animal/tree interactions, with less attention paid to animal/soil interactions in silvopastures. While a considerable body of work has been devoted to understanding the effects of livestock trampling on plants and soils in pastures, less has been done for livestock grazing in forests, and even less is available for silvopastures. Three replications of Douglas-fir forest, Douglas-fir/subclover pasture/sheep silvopasture, and subclover/sheep pasture were established in 1989 near Corvallis, Oregon USA. Pastures and silvopastures were grazed each spring during 1990–2001. These plots were sampled in 2002, after 11 years of grazing, and again in 2004 following 2 years without grazing. Soil in the silvopastures had 13% higher bulk density and 7% lower total porosity than those in adjacent forests in 2002. Most of the difference in total porosity was air-filled pores. Average water infiltration rate was 38% less in silvopastures than in forests, however total water stored in the top 6 cm of soil at field capacity was similar. Soil bulk density, total porosity, and air-filled pore space was similar for forests, pastures, and silvopastures after 2 years without livestock grazing. The infiltration rate of silvopasture soils in 2004 had increased to be similar to those of forests in 2002, however, forest soil infiltration rates also increased and continued to be higher than those of silvopastures. Plant production was not sensitive to changes in any of the soil parameters measured. Although livestock grazing did change soil infiltration rates, soil bulk density, and soil porosity, the effects were quickly reversed following cessation of grazing and had little detrimental effect on silvopasture forage or tree production.
99 citations
TL;DR: In this article, a discounted cash flow analysis was carried out to estimate the benefit-cost (B/C) ratio, net present value (NPV), internal rate of return (IRR) and land expectation value (LEV) as well as the sensitivity to a 20% decline in cocoa prices and additional chemical costs for various shade scenarios at a 10% discount rate.
Abstract: The cultivation of cocoa has been an important driver of tropical deforestation glob- ally. Efforts to reverse this trend are focusing on the reintroduction of shade trees to cocoa plan- tations. Shade trees are valuable in enhancing biophysical conditions on cocoa (Theobroma cacao) fields and contribute to biodiversity and product diversification for smallholder producers. Participatory trials of cocoa agroforests planted with indigenous shade tree species were under- taken with farmers in the Atwima District of the Ashanti Region of Ghana, to increase tree volume on cocoa fields while improving rural livelihoods and enhancing environmental sustain- ability. An ex ante financial analysis of the technology was undertaken to assess its economic viability. Input-output data were collected from farmer experiments over three seasons and sup- plemented with data from traditional cocoa fields of varying rotation ages, and secondary data on production in later years of an eighty-year cocoa rotation. A discounted cash flow analysis was carried out to estimate the benefit-cost (B/C) ratio, net present value (NPV), internal rate of return (IRR) and land expectation value (LEV) as well as the sensitivity to a 20% decline in cocoa prices and additional chemical costs for various shade scenarios at a 10% discount rate. It was observed that cocoa production is, in general, profitable. The change from the traditional sys- tem to one with hybrid cocoa raised the IRR from 31% to 57% with planted shade and 67% without, although extra agrochemical costs would tend to reduce the profitability of unshaded hybrid cocoa in particular. The age of maximum LEV for the various scenarios suggests that the optimum economic rotation for the hybrid cocoa is between 18 and 29 years, much less than the traditional system.
98 citations
TL;DR: It appears that heavily shaded dominant temperate pastures in silvopastoral systems limit animal production per hectare through lower DM production rates and per animal through reduced pre-grazing pasture mass of lower bulk density from the etiolated pasture.
Abstract: Plant growth, morphology and nutritive value under shade can differ between temperate grasses. Therefore, the aim of this study was to quantify the dry matter (DM) production, sward morphology, crude protein (CP%), organic matter digestibility (OMD) and macro-nutrient concentrations (P, K, Mg, Ca and S) in a grazed cocksfoot (Dactylis glomerata L.) pasture under 10-year-old Pinus radiata D. Don forest. Four levels of light intensity were compared: full sunlight (100% photosynthetic photon flux density-PPFD), open + wooden slats (∼43% PPFD), trees (∼58% PPFD) and tree + slats (∼24% PPFD). The mean total DM production was 8.2 t DM ha−1 yr−1 in the open and 3.8 t DM ha−1 yr−1 in the trees + slats treatment. The changes in cocksfoot leaf area index (LAI) were related to variations in morphological aspects of the sward such as canopy height and tiller population. CP% increased as PPFD declined with mean values of 18.6% in open and 22.5% in the trees + slats treatment. In contrast, the intensity of fluctuating shade had little effect on OMD with a mean value of 79 ± 3.2%. The mean annual macro-nutrient concentrations in leaves increased as the PPFD level declined mainly between the open and the trees + slats treatments. It therefore appears that heavily shaded dominant temperate pastures in silvopastoral systems limit animal production per hectare through lower DM production rates and per animal through reduced pre-grazing pasture mass of lower bulk density from the etiolated pasture.
87 citations
TL;DR: In this article, the authors analyzed dehesa farms in the Extremadura region (SW Spain) using technical and economic indicators of 69 randomly selected holdings and established a valid model explaining 65.8% of the variance.
Abstract: Dehesa agroforestry systems occupy around 6 million ha in the Iberian Peninsula. Their economic and environmental sustainability depends on the maintenance of the extensive livestock farms which created this typical ecosystem. This work analyzes dehesa farms in the Extremadura region (SW Spain) using technical and economic indicators of 69 randomly selected holdings. Principal component analysis (PCA) allowed us to establish a valid model explaining 65.8% of the variance. The two principal components having most weight were Iberian pig production (explaining 20% of the variance of the model), and which ruminant species were raised on the farm (15% of the variance). A cluster analysis distinguished five types of farms: sheep farms at high and low stocking rates, beef cattle farms, wooded farms with mixed livestock, and farms with a high level of cropping activity. The most profitable farms were those with either high overall livestock density or a high level of Iberian pig production. While high stocking density has historically attracted high levels of subsidy, production of Iberian pigs was profitable because of the high value of the product. In the light of CAP reform, Iberian pig production seems the most readily sustainable type of farming for the dehesa system.
83 citations
TL;DR: In this paper, the authors quantify carbon stored in surface soil layers and tree litter within and adjacent to a 35-year-old shelterbelt in eastern Nebraska, USA, composed of eastern red cedar (Juniperus virginiana) and scotch pine (Pinus sylvestris).
Abstract: Carbon sequestration in the woody biomass of shelterbelts has been investigated but there have been no measurements of the C stocks in soil and tree litter under this agroforestry practice. The objective of this study was to quantify C stored in surface soil layers and tree litter within and adjacent to a 35-year-old shelterbelt in eastern Nebraska, USA. The 2-row shelterbelt was composed of eastern red cedar (Juniperus virginiana) and scotch pine (Pinus sylvestris). A sampling grid was estab- lished across a section of the shelterbelt on Tomek silt loam (fine, smectitic, mesic Pachic Argiudolls). Four soil cores were collected at each grid point, divided into 0-7.5 and 7.5-15 cm depth increments, and composited by depth. Soil samples were analyzed for total, organic, and inorganic C, total N, texture, pH, and nutrient content. Under the shelterbelt, all surface litter in a 0.5 · 0.5 m 2 area at each grid point
82 citations
TL;DR: An efficient and improved shoot regeneration technique for the micropropagation of Vitex negundo through in vitro culture of nodal segments with axillary buds is described and no phenotypical differences for morphogenesis were observed among the regenerants.
Abstract: An efficient and improved shoot regeneration technique for the micropropagation of Vitex negundo, an aromatic and medicinal shrub through in vitro culture of nodal segments with axillary buds, is described. Thidiazuron (TDZ) used at 1.0 μM was the most effective in inducing bud break and growth, and also in initiating multiple shoot proliferation at the rate of 25 microshoots per nodal explant with axillary buds, after 4 weeks of culture. By repeated subculturing of nodal explants, a high-frequency multiplication rate was established. Optimum shoot multiplication and elongation was achieved when TDZ exposed explants were subcultured on Murashige and Skoog (MS) media containing a combination of 1.0 μM 6-benzyladenine (BA) and 0.5 μM α-naphthalene acetic acid (NAA). Efficient rooting was achieved directly in soilrite when basal portion of the shoots were treated with 500 μM indole-3-butyric acid for 10 min which was the most effective in inducing roots, as 97% of the microshoots produced roots. Plantlets went through a hardening phase in a controlled plant growth chamber, prior to ex-vitro transfer. Micropropagated plants grew well, attained maturity and flowered. No phenotypical differences for morphogenesis were observed among the regenerants.
79 citations
TL;DR: The objective was to develop tools to manage this valuable resource within silvopastoral systems in the Mediterranean region and to analyze the distribution of production over time and the effect of pruning.
Abstract: Acorn production is one of the most important products in silvopastoral systems in the Mediterranean region. In the present study we carried out two preliminary trials to analyze the distribution of production over time and the effect of pruning. The objective was to develop tools to manage this valuable resource within these systems. In the first part of the study, we analyzed the total acorn production of a holm oak stand, and its seasonal distribution (October–January) over two years (1997–1998 and 1998–1999) in five sites in the southwest of Spain. Mean total acorn production ranged from 590 to 830 kg ha−1. There was considerable variation between the different sites and years studied, as was expected from studies on other oak species. A comparison was also made of acorn production, comparing annual acorn production between 40 pruned and 40 non-pruned trees, for the period 1994–1999. There was an interaction between ‘pruning treatment’ and ‘year’. Pruning, significantly decreased acorn production in all but two years when production was above the average, whereas production was not affected by pruning the three years that acorn yield was below the average. The study of acorn production and the analysis of the effect of pruning, needs to be studied over a longer time period.
TL;DR: There were significant variations in the analysed soil nutrients between the tree species, and topsoil under Millettia and Cordia had significantly higher levels of exchangeable Ca and Mg than Red gum.
Abstract: Based on farmers’ knowledge and laboratory studies, the nutrient accumulation in the topsoil (0–20 cm) under Cordia africana Lam (Cordia), Millettia ferruginea Hochst (Millettia) and Eucalyptus camaldulensis Dehnhardt (Red gum) managed under two agroforestry practices on different farms at three sites was evaluated. The number of these trees on individual farms has increased during the last two decades. The number of stems ha−1 of Red gum was higher on farms of wealthier households than on farms of poor and medium households at two of the sites, but, at one site the number of stems ha−1 on farms of poor households was higher than on farms of wealthier households. Apart from the concentration of Na in the topsoil, there were significant variations in the analysed soil nutrients between the tree species. At all study sites, significantly higher concentration of P was observed under Millettia and Cordia than under Red gum. At one site, concentrations of available P under Cordia were nearly two-fold, and four and half-fold greater than under Millettia and Red gum, respectively. At one site, total N under Red gum was 14% and 24% lower than under Cordia and Millettia, respectively. In contrast, organic C content under Red gum was 11.6% greater than under Millettia and 23.8% greater than under Cordia. The pH under Millettia and Cordia were significantly higher than concentrations under Red gum at one site. Topsoil under Millettia and Cordia also had significantly higher levels of exchangeable Ca and Mg than Red gum.
TL;DR: In this article, a randomized complete block experiment was adopted to assess effects of five tree species on soil nutrients status, nutrient use efficiency and wood yield in semi-arid Tanzania.
Abstract: Frequent nutrient removals accompanying wood and crop harvests from rotational woodlot systems may contribute to declining site productivity and sustainability because of soil nutrient depletion. However, selecting for nutrient-efficient tree species may well sustain productivity under this system. To test this hypothesis, a randomized complete block experiment was adopted to assess effects of five tree species on soil nutrients status, nutrient use efficiency and wood yield in semi-arid Tanzania. After 5 years rotation, top soils under Gliricidia sepium (Jaqua), Acacia polyacantha Willd. and Acacia mangium Willd. were the most fertile with soil organic carbon and exchangeable cation status raised close to those in natural Miombo systems. Soil inorganic N and extractable P levels reached sufficiency levels for subsequent maize culture. Wood productivity in tree fallows averaged three times higher than that of Miombo woodlands indicating the high potential of the woodlot system to supply fuelwood, and consequently relieve harvesting pressures on the natural forests. Acacia crassicarpa A. Cunn. ex Benth. produced the most wood (51 Mg ha−1) at low nutrient “costs” presumably due to high nutrient use efficiency. Wood yield of this species was 42 and 120% greater than that of A. polyacantha and A. nilotica, respectively, but contained comparatively less nutrients (42–60% less for P, K, and Ca). Gliricidia sepium and A. polyacantha returned the largest amount of nutrients through slash at harvests. Of all test species, A. crassicarpa exhibited the most promise to sustain wood production under rotational woodlot systems due to relatively high productivity and low nutrient export at harvest.
TL;DR: Poplar (Populus deltoides Bartr.) based agroforestry systems are economically viable and more sustainable than many other crop rotations prevalent in northern India and the increase was higher in four year old plantations than one year due to higher inputs of organic matter.
Abstract: Poplar (Populus deltoides Bartr.) based agroforestry systems are economically viable and more sustainable than many other crop rotations prevalent in northern India. Growth {girth at breast height (GBH) and height} and productivity (volume) of clone G-48 of poplar spaced at 5 x 4 m, soil organic carbon (OC), and concentration of available macronutrients (N, P and K) and micronutrients (Zn, Fe, Mn and Cu) in surface soil (0-15 cm depth) were determined at an interval of six months starting from April 2002 till October 2003 in one and four year old (in January 2002) 16 poplar plantations on farmers' fields in Ludhiana, Punjab. The observations were taken from plantations having fodder {sorghum (Sorghum bicolor)/pearlmillet (Pennisetum americanum) in summer}-wheat (Triticum aestivum) (in winter) rotation throughout the poplar age and those having sugarcane (Sachharum officinarum) initially during two years and fodder-wheat rotation thereafter. The GBH, height and volume of younger plantations intercropped with fodder-wheat rotation were 15.6, 17.2 and 46.7%, respectively higher than that of plantations intercropped with sugarcane. Growth increment of poplar was markedly higher during April to October than October to April. Soil OC was significantly greater in older (6.83 g kg-1) than the younger (5.35 g kg-1) plantations. Available macronutrients in soil increased at successive sampling times. The average Zn concentration at final sampling was 17% lower compared to initial sampling, whereas the other micronutrients tended to increase during April 2002 to October 2003 and the increase was higher in four year old plantations than one year due to higher inputs of organic matter.
TL;DR: In this article, a 20-year old agroforestry plantation consisting of five multipurpose tree species (Pinus kesiya Royle ex-Gordon, Alnus nepalensis D.Don, Michelia oblonga Wall, and Gmelina arboria Roxb) was studied under normal recommended practices at Indian Council of Agricultural Research (ICAR) Complex, Umiam, Meghalaya, India.
Abstract: Soil hydro-physical behaviour was studied under a 20-year old agroforestry plantation consisting of five multipurpose tree species (Pinus kesiya Royle ex-Gordon, Alnus nepalensis D.Don, Parkia roxburghii G.Don, Michelia oblonga Wall. and Gmelina arboria Roxb.) maintained under normal recommended practices at Indian Council of Agricultural Research (ICAR) Complex, Umiam, Meghalaya, India. The aim was to select tree species, which could act as better bio-ameliorant as well as provides higher economic return in highly degraded soil of northeastern hill region of India. A site without vegetation (no tree) nearby the plantation was also selected as control for comparison. Soil samples for various hydro-physical analysis, were taken from 0–15 and 15–30 cm soil depth at a distance of 1 m from respective tree species during wet and dry season of 2003–2004. No appreciable differences in relative contents of textural separates of sand, silt and clay were observed among various tree covers. Surface cover with constant leaf litter fall and extensive root system increased soil organic carbon, helped in better soil aggregation, improved water transmissivity and infiltrability and in turn, reduced soil erosion in the present study. However, due to variation in quantity of leaf litter fall and root biomass, these parameters differed among tree species. Of the tree species, P. kesiya, M. oblonga and A. nepalensis were found to be rated best for bio-amelioration of soils as these tree covers had more root and shoot biomass and more litter fall compared to other species. However, considering both timber production and improvement in hydro-physical behaviour, M. oblonga was found best among the tested tree species. The study, thus, suggested that inclusion of tree species M. oblonga in agroforestry system is a viable option for natural resource management and could sustain long-term soil productivity in a highly degraded soil of this region as well as for food security of the resource poor people of North East India.
TL;DR: Research in agroforestry should take into account the developmental differences in root systems of the associated crop species so that better models incorporating nutrient and water uptake can be developed.
Abstract: A study was conducted in northwest Florida, USA, to investigate root development and morphology of cotton (Gossypium hirsutum L.) under pecan (Carya illinoensis K. Koch) trees in an alleycropping experiment. Root:shoot ratio, root biomass, total root length and root length density were examined under three treatments: (1) barrier (separating belowground interspecific competition by trenching to a depth of 120 cm and installing polyethylene barrier), (2) non-barrier (root systems were free to interact), and (3) monoculture of cotton (without above and belowground interspecific competition with trees). Results indicated that plants in the barrier and non-barrier treatments had lower root:shoot ratios compared to the monoculture treatment. Belowground competition for resources between pecan and cotton in the non-barrier treatment resulted in 25 and 33% reduction of total root length (359 cm) when compared to that of the barrier (477 cm) and monoculture (539 cm) treatments, respectively. The non-barrier plants also exhibited the lowest root length density. Specific root length was highest for the monoculture (179 cm g−1) and lowest for the non-barrier treatment (146 cm g−1) with the barrier treatment being intermediate (165 cm g−1). Interspecific competition with pecan significantly altered root development and morphology of cotton plants. Research in agroforestry should take into account the developmental differences in root systems of the associated crop species so that better models incorporating nutrient and water uptake can be developed.
TL;DR: Birds normally associated with woodland are being attracted to silvopasture along with birds normally found in open fields, although there are problems in the scale of evaluation in the assessment of impact.
Abstract: Silvopastoral systems, where stock graze between widely spaced trees, are a viable land use option in the British Isles. An experiment (the National Network Silvopastoral Experiment—NNE) was set up at 6 sites in the late 1980s to quantify outputs from and to study the ecological interactions occurring between components of the system. Studies were carried out on the effect of developing silvopastoral systems on certain invertebrate groups, including carabid beetles and spiders and on the number of individuals and species of birds. The common protocols adopted across sites enable broad conclusions on the impact of such systems on wildlife to be made. The presence of trees on grassland attracted invertebrates of epigeal groups which may have provided an enhanced food supply which attracted birds. Spiders responded more rapidly after planting of the silvopastoral systems than did carabid beetles. It was concluded that, even at this early stage, silvopastoral systems have an impact on birds: birds normally associated with woodland are being attracted to silvopasture along with birds normally found in open fields, although there are problems in the scale of evaluation in the assessment of impact. However, it has been shown that even relatively recently established silvopastoral systems can significantly enhance biodiversity.
TL;DR: The study indicated that by the sixth growing season, annual pasture production under different tree species is inversely correlated with tree leaf area index, with the last sampling showing the inverse relationship between tree density and herbage production most clearly.
Abstract: We studied the effect of six tree species planted at six different densities on pasture production seven years after establishment. Annual and seasonal pasture production was studied every six months, over three years. Pasture production was lower under conifer trees (Pseudotsuga menziesii (Mirb.) Franco, Pinus pinaster Aiton, Pinus radiata D. Don) than under broadleaved trees (Betula alba L., Quercus rubra L. and Castanea sativa Mill.). Annual pasture production under Pseudotsuga menziesii and Pinus pinaster decreased progressively starting from 952 trees ha−1, while decline in herbage production under Pinus radiata began to occur at 427 trees ha−1. Tree density effect on pasture production was detected at 2,000 trees ha−1 for all of the deciduous species studied. This effect on pasture production was more important in the first six months of the year (June sampling), while from June to December herbage production was less affected by tree density. The tree effect became more noticeable over time, with the last sampling showing the inverse relationship between tree density and herbage production most clearly. Seven years after tree establishment, pasture production was quite consistent under tree densities between 190 trees ha−1 and 556 trees ha−1 and declined remarkably from 556 trees ha−1 to 2,500 trees ha−1. The study also indicated that by the sixth growing season, annual pasture production under different tree species is inversely correlated with tree leaf area index.
TL;DR: Canarium indicum is an indigenous tree of the lowland forests of Melanesia (Papua New Guinea, Solomon Islands, Vanuatu) and parts of Indonesia producing edible nuts, commercial timber and some minor products as mentioned in this paper.
Abstract: Canarium indicum is an indigenous tree of the lowland forests of Melanesia (Papua New Guinea, Solomon Islands, Vanuatu) and parts of Indonesia producing edible nuts, commercial timber and some minor products. For thousands of years the nuts have been culturally important and a traditional food. Since the early 1990s there have been a number of projects aimed at the wider commercialization of the species, with mixed success. This review evaluates the biophysical and socio-economic literature and suggests how the domestication and commercialization processes could be taken forwards to improve the livelihoods of rural households in Melanesia. Many of the issues facing the domestication and commercialization of C. indicum nuts as an Agroforestry Tree Product (AFTP) are similar to those that will be important for the development of other AFTPs. Thus there are lessons that can be learnt from this species which make it a model for other agroforestry tree species.
TL;DR: In this article, root development of wide-spaced poplar trees on hillslopes was minimal in the first 5 years but then increased rapidly in the last 5 years, suggesting that it may take at least 5 years to develop a structural root network that will effectively bind soil.
Abstract: In New Zealand poplars are commonly planted on moist, unstable pastoral hill country to prevent or reduce soil erosion, thereby maintaining hillslope integrity and pasture production. Mechanical reinforcement by poplar root systems aids slope stabilisation. Root mass and distribution were determined for three Populus deltoides × nigra ‘Veronese’ trees aged 5, 7 and 9.5 year planted as 3 m poles at 8 m × 8 m spacing on a hillslope near Palmerston North in the southern North Island. Most of the structural roots (≥2 mm diameter) were distributed in the top 40 cm of soil. Vertical roots penetrated to about 1.0 m, being the depth of the soil above a fragipan. Total structural root dry masses (excluding root crown) were 0.57, 7.8 and 17.90 kg for the trees aged 5, 7 and 9.5 year, respectively. Total structural root length was 79.4 m for the 5 year tree and 663.5 m for the 9.5 year tree. Surrounding trees were estimated to increase root mass density to 3 times and root length density to 4–5 times the contribution of the single tree at 9.5 year. The study indicated that root development of wide-spaced poplar trees on hillslopes was minimal in the first 5 years but then increased rapidly. These results suggest that poplar trees established from poles may take at least 5 years to develop a structural root network that will effectively bind soil.
TL;DR: It was concluded that the greatest effect of poplar was on pasture production due to shading, and that management of this silvopastoral system needs to focus on control of the tree canopy to lessen the decrease in pasture production.
Abstract: Traditionally, poplar (Populus spp.) have been planted to control erosion on New Zealand’s hill-slopes because of their capacity to dry out and bind together the soil. Two systems: (1) widely spaced, planted poplar for soil conservation, and (2) non-eroded open pasture were compared to determine the relative effect of the poplar–pasture system on the production, nutritive value and species composition of the pasture, and on the water balance. Measurements were made at three sites with mature poplar (>29 years and 37–40 stems ha−1) and at a replicated experiment with young poplar (5 years, 50–100 stems ha−1). Soil water relations did not suggest strong competition for water between poplar and pasture. Pasture accumulation under mature poplar was 40% less than in the open pasture, but under young poplar was similar to that in the open pasture. Chemical composition of pasture suggested that feed quality of pasture in the open was better than under the poplar canopy, except during spring, when most chemical components were similar. At the most, in vitro digestibility of pasture dry matter was 8.9% lower and metabolisable energy of pasture dry matter was 1.5 MJ kg lower under the poplar canopy than in the open pasture. Shade tolerant species were not dominant in the plant community under the poplar canopy with grasses such as browntop (Agrostis capillaris, L.) and ryegrass (Lolium perenne, L.) being a high proportion of the plant community. Differences in chemical composition were related to differences in the botanical composition between the open pasture and the poplar understorey. It was concluded that the greatest effect of poplar was on pasture production due to shading, and that management of this silvopastoral system needs to focus on control of the tree canopy to lessen the decrease in pasture production.
TL;DR: Allelopathic behaviour of three medicinal herbs viz.
Abstract: Allelopathic behaviour of three medicinal herbs viz. Rheum emodi, Saussaurea lappa and Potentilla fulgens, on some traditional food crops was examined. Germination of all the traditional food crops was reduced significantly under aqueous extracts of S. lappa and P. fulgens but radicle and plumule growth of Amaranthus
caudatus and Eleusine coracana was reduced significantly under aqueous extracts of all three medicinal species. For marginal farmers sole medicinal plants cultivation is not possible, therefore, medicinal plants based agroforestry is being propagated.
TL;DR: Liming and sewage sludge fertilization increased soil pH and reduced saturated aluminium percentage in the interchange complex (Al/IC) in the soil, coming up the effect before with liming.
Abstract: In recent years, in the European Union, sewage sludge production has been increased as a result of EU policy (European directive 91/271/EEC). Organic matter and nutrient sewage sludge contents, principally nitrogen, indicate it can be used as fertilizer. The objective of the experiment was to compare the effect of no fertilization, three doses of sewage sludge, with or without liming, and the fertilization usually used in the region applied over a period of 3 years on pasture production and tree growth in a silvopastoral system. The experiment was conducted in the northwest of Spain. The soil was very acid (soil pH = 4.5) and had very low nutrient levels, especially P, that is related to site index. It was sown with a grass mixture (25 kg ha−1 of Lolium perenne L. 10 kg ha−1 of Dactylis glomerata L. and 4 kg ha−1 of Trifolium repens L.) in Autumn 1997 under a plantation of 5-year-old Pinus radiata D. Don at a density of 1,667 trees ha−1. Liming and sewage sludge fertilization increased soil pH and reduced saturated aluminium percentage in the interchange complex (Al/IC) in the soil, coming up the effect before with liming. Medium and high sewage sludge doses increased pasture production in the two first years. In a silvopastoral system, positive tree growth response to different fertilization treatments depended on tree age, initial soil fertility, soil pH, the relationship of competition with pasture production and previous liming application.
TL;DR: Vegetation dynamics in previously burnt shrublands dominated by gorse in north-west Spain were studied during 4 years under different grazing managements with sheep and goats, showing that goats control the regrowth of gorse more effectively than sheep.
Abstract: Vegetation dynamics in previously burnt shrublands dominated by gorse (Ulex gallii) in north-west Spain were studied during 4 years under different grazing managements with sheep (Gallega breed) and goats (Cashmere or local breed). Initially (Period 1), treatments consisted of sheep or goat grazing on four plots (two replicates). After two grazing seasons, the plots were split in two and the treatments were reversed in four of the subplots; sheep were placed in subplots previously grazed by goats and vice versa (Period 2). The results from Period 1 showed that goats control the regrowth of gorse (from 19.6 to 14.2% of cover) more effectively than sheep (17.8 to 27.0% cover; P < 0.05), favouring the increase in herbaceous plants (from 21.5 to 42.1% of cover under goat grazing and from 22.1 to 26.6% under sheep grazing; P < 0.01). In Period 2, after changing treatments, there was a clear effect of the previous management (P < 0.01), conditioning the dynamics of the different plant components. Where the same animal species were maintained for 4 years, the differences between sheep or goat grazing on gorse and herbaceous plant dynamics increased (24.4% of gorse and 35.2% of herbaceous plant cover under goat grazing vs 43.8% of gorse cover and 19.1% of herbaceous plant cover under sheep grazing). Animal species change buffered the differences between sheep and goats during the second Period.
TL;DR: Preliminary evidence is offered that Bradyrhizobium elkanii strains from A. adianthifolia in Ghana have evolved in response to local differences in seasonal water availability, which could assist the selection of A.AdianthIFolia provenances for agroforestry or land rehabilitation.
Abstract: Albizia adianthifolia (Schumach) W. F. Wright, a N-fixing legume tree, has a wide distribution in Africa, in Ghana occurring in high rainfall forests and in seasonally droughted forests, and is associated in the Ghanaian forest zone with dry, infertile sites. We hypothesised that A. adianthifolia hosted different rhizobial strains in different forest types, and that these different strains would show different growth responses to moisture stress and different motility and mortality in droughted soil. Three isolates, extracted from seedlings of A. adianthifolia growing in three forest types differing in seasonal drought, were identified as Bradyrhizobium elkanii and exposed to varying levels of osmotic stress. Growth responses varied between the three strains, one of which displayed clear signs of drought tolerance. A novel approach using soil leaching columns was used to test the effects of soil pore water (in terms of neck diameter) on both the survival and movement of wet and dry forest rhizobial isolates through soil columns. The responses of the isolates were significantly different, the pore neck diameter, marginally insignificant and the drought treatment insignificant. Thus the dry forest isolate survived better in all treatments, and showed less response to the treatments, than the isolate from the wet forest. The results offer preliminary evidence that Bradyrhizobium elkanii strains from A. adianthifolia in Ghana have evolved in response to local differences in seasonal water availability. These differences could assist the selection of A. adianthifolia provenances for agroforestry or land rehabilitation.
TL;DR: In this paper, ground water table (g.w.t.) levels were measured twice a month for 2 years in 50 observation wells installed inside and outside the two 18-year-old and 350 m apart plantations of Eucalyptus tereticornis (Mysure gum) at a research plot located in Rohtak district of Haryana state (north-west India).
Abstract: Ground water table (g.w.t.) levels were measured twice a month for 2 years in 50 observation wells installed inside and outside the two 18-year-old and 350 m apart plantations of Eucalyptus tereticornis (Mysure gum) at Dhob-Bhali research plot located in Rohtak district of Haryana state (north-west India). Throughout the study, the g.w.t. underneath the plantations remained lower than the g.w.t. in the adjacent fields. The average g.w.t. in the plantations was 4.95 m and the average g.w.t. in the control located in adjacent fields was 4.04 m. Interestingly, the spatial extent of lowering of g.w.t. in the adjacent fields was up to a distance of more than 730 m from the edge of a plantation. Drawdown in the g.w.t. developed due to the effect of a plantation was similar to the cone of depression of a pumping well and the drawdown in the g.w.t. developed due to the joint effect of both the plantations was similar to the combined cone of depression of two pumping wells. There was no correlation between soil salinity and the g.w.t. The fluctuations in g.w.t. caused fluctuations in g.w.t. salinity in the plantation as well as in the adjacent fields, but there was no net increase in g.w.t. salinity underneath the plantation. Sinker roots of Eucalyptus tree reached the zone of capillary fringe up to a depth of 4.40 m, indicating that the Eucalyptus trees were absorbing capillary water of the g.w.t. Thus, in shallow g.w.t. areas of semi-arid regions with alluvial sandy loam soils, the plantations of E. tereticornis act as bio-pumps and therefore, we recommend closely spaced parallel strip plantations of this species for the reclamation of waterlogged areas.
TL;DR: In this paper, a patch-corridor-matrix model was used to classify patches and their delineation in agro-silvo pastoral landscapes of the Mediterranean, and the consequences of the complexity of some Mediterranean land use systems for land cover mapping dealing with detailed landscape dynamics were discussed.
Abstract: This paper contributes to the discussion on current issues in methodologies of mapping land cover in the agro-silvo-pastoral landscapes of the Mediterranean These landscapes, characterized by intermixed land use and indefinite boundaries, require particular attention in applying the patch-corridor-matrix model when classifying patches and their delineation In a case study area in southeast Portugal, mainly characterized by agro-silvo pastoral systems, the land cover for 1990 has been mapped The paper discusses the consequences of the complexity of some Mediterranean land use systems for land cover mapping dealing with detailed landscape dynamics Within this scope a land cover mapping project in a small case study area is compared with the mapping undertaken within a national land cover database Both studies were carried out on the same scale and through visual interpretation of aerial photographs Differences in land cover classification and allocation are explored using matrix with levels of agreement Recommendations for future land cover mapping projects are: the application of fuzzy approaches to land cover mapping in agro-silvo-pastoral landscapes should be explored and land cover classifications should be standardized in order to enhance consistency between databases On the other hand, the fuzziness of the boundaries in this kind of landscapes is inherent to the system and should be accepted as such The accompanying uncertainties should be taken into account when undertaking landscape analysis on the basis of land cover data
TL;DR: Koumantou’s favourable climatic conditions resulted in better flowering ability and a higher probability of abundant flowering, and field appeared to provide better conditions than fallow and forest regarding flowering ability, however, tree diameter did not affect flowering phenology.
Abstract: The impact of human practices on the phenology of flowering was assessed for an important agroforestry tree species of the Sudano-Sahelian zone: Vitellaria paradoxa. Flowering was monitored at two sites in southern Mali over 2 years. At each site, the impact of agricultural practices on flowering phenology was assessed by comparing field, fallow and forest. The site effect and agricultural practices were significant for all the monitored variables. The proportion of individuals that flowered was 89% at Koumantou and 40% at MPeresso. About 98, 95 and 75% of individuals at Koumantou and 88, 12 and 20% at MPeresso flowered in the field, fallow and forest, respectively. The mean length of flowering ranged from 69 to 81 days at Koumantou and from 45 to 108 days at MPeresso. The mean number of days for the active phase ranged from 36 to 49 days at Koumantou and from 27 to 64 days at MPeresso. Koumantou's favourable climatic conditions resulted in better flowering ability and a higher probability of abundant flowering. Field appeared to provide better conditions than fallow and forest regarding flowering ability and probability of abundant flowering. However, tree diameter did not affect flowering phenology. Agricultural practices appear to have a noticeable impact on the phenology of flowering of V. paradoxa. Trees flowered abundantly in the parkland and therefore increased gene flow via pollen and/or seeds and the dynamics of genetic diversity.
TL;DR: In this article, the authors investigate farmers' views on small-scale fruit-tree cultivation based on fieldwork conducted in three upland villages of Northeast Luzon in the Philippines, and the costs and benefits of fruit tree cultivation compared with those for seasonal cash crops over a 10-year period.
Abstract: The world production of tropical fruit was estimated at about 65 Mt in 2002, of which developing countries accounted for 98%. Although most commercial fruit tree crops are cultivated by large-scale commercial enterprises, smallholder fruit-tree cultivation receives much attention in projects aimed at rural development, conservation farming and agroforestry in developing countries. In the Philippines, the integration of fruit trees in smallholder upland farming systems has been promoted since the 1970s. The aim of this paper is to investigate farmers' views on small-scale fruit-tree cultivation based on fieldwork conducted in three upland villages of Northeast Luzon. The factors influencing farmers' preferences are explored and the costs and benefits of fruit tree cultivation compared with those for seasonal cash crops over a 10-year period. Markets for fruit-tree products are identified, at both local and supra-local levels, and risks, uncertainties and opportunities associated with fruit-tree cultivation are discussed. Despite extensive promotion, the adoption of fruit trees in farming systems has occurred at a relatively low pace. In contrast, the cultivation of seasonal cash crops, particularly high-yielding rice and corn varieties, spread rapidly in the 1970s and 1980s. These crops are planted in monocultures with high inputs of fertilizers and pesticides. Farmers consider fruit trees as a subordinate crop much less profitable than seasonal cash crops, which is in stark contrast with the results of economic analyses of a 10-year production cycle. The Net Present Value (NPV) for citrus (Citrus reticulate) cultivation is at least two times the NPV for irrigated rice and as much as four times the NPV for corn, even at discount rates up to 20%. Farmers' knowledge of tree management and species selection proved to be inadequate, contributing indirectly to low growth rates and fruit production. Marketing opportunities are not fully utilised as evident from unstable network channels for fruit-tree sales, lack of expertise in fruit-tree marketing and insufficient knowledge on market demands, quality production and market location.
TL;DR: This study showed that E. poeppigiana responded better to pruning regimes than G. sepium, and recovery of trees after pruning is better when trees are partially pruned than when completely pruned.
Abstract: In alley cropping systems, fast growing leguminous trees are pruned to reduce competition with crops for light and to provide organic inputs for crop nutrition. Tree regrowth depends on non-structural carbohydrate reserves in the remaining tree parts. In this study, the dynamics of starch and soluble carbohydrates in roots and stems of completely pruned (all shoots removed), partially pruned (one branch retained on the pruned stump) and unpruned Erythrina poeppigiana (Walp.) O.F. Cook and Gliricidia sepium (Jacq.) Kunth ex Walp. trees were studied under humid tropical conditions in Turrialba, Costa Rica. Measurements on starch and soluble carbohydrates in roots and stems were made at 0, 2, 6 and 12 weeks after pruning during both a “rainy” and a “dry” season. In general, the dynamics of non-structural carbohydrates in roots and stems of pruned E. poeppigiana and G. sepium trees were similar. Starch concentration was highest in unpruned trees and higher in roots than in stems of pruned trees. The effect of pruning intensity was first observed in stems, and starch reserves were more depleted in stems than in roots, an effect more evident during the “dry” season. The critical tree regrowth stage for starch mobilisation was that of vigorous sprout development at six or four weeks after pruning particularly in completely pruned trees. At this time, fine root biomass and length and nodule biomass in pruned trees decreased. Survival of fine roots and nodules was greater in partially pruned than in completely pruned trees. Starch accumulation in roots recommenced at 12 weeks after pruning in G. sepium, and later than 12 weeks after pruning in E. poeppigiana roots. This study showed that E. poeppigiana responded better to pruning regimes than G. sepium. Recovery of trees after pruning is better when trees are partially pruned than when completely pruned.