Analysis of existing agroforestry practices in Madhupur Sal forest: an assessment based on ecological and economic perspectives

A study was conducted in Madhupur sal forest of Tangail, Bangladesh to identify the suitable agroforestry practices of the area. Considering the ecological aspects of different agroforestry practices 10 sample plots (10 m × 10 m) from each land uses were taken, including natural forest to get a comparative scenario. The study showed that among the different agroforestry practices, Margalef and Shannon-Weiner index values are the maximum for pineapple agroforestry and lower for banana agroforestry, and Evenness index value is the maximum for lemon agroforestry. Determination of tree biomass in different land uses revealed that it is highest (3 078.6 kg/100 m²) in natural forest followed by pineapple agroforestry, lemon agroforestry and banana agroforestry. Soil pH, moisture content, organic matter, organic carbon, phosphorus and total nitrogen showed statistically significant variation while bulk density, particle density, sulphur and potassium did not show any statistically significant variation among the land uses. Soil fertility status showed that pineapple agroforestry is more fertile than rest of other land uses. The Net Present Value (NPV) indicated that banana agroforestry is financially more profitable than other two systems, while the Benefit-Cost ratio (BCR) is higher in pineapple agroforestry (4.21 in participatory agroforestry and 3.35 in privately managed land). Even though banana agroforestry gives higher NPV, capital required for this practice is much higher. The findings suggest that pineapple agroforestry has a tendency towards becoming ecologically and economically more sound than other two practices as it has better ecological attributes and required comparatively low investment.     

Agroforestry strategies to sequester carbon in temperate North America

Information on carbon (C) sequestration potential of agroforestry practices (AP) is needed to develop economically beneficial and ecologically and environmentally sustainable agriculture management plans. The synthesis will provide a review of C sequestration opportunities for AP in temperate North America and the estimated C sequestration potential in the US. We estimated carbon sequestration potential for silvopasture, alley cropping, and windbreaks in the US as 464, 52.4, and 8.6?Tg?C?yr^?1, respectively. Riparian buffers could sequester an additional 4.7?Tg?C?yr^?1 while protecting water quality. Thus, we estimate the potential for C sequestration under various AP in the US to be 530?Tg?yr^?1. The C sequestered by AP could help offset current US emission rate of 1,600?Tg?C?yr^?1 from burning fossil fuel (coal, oil, and gas) by 33?%. Several assumptions about the area under different AP in the US were used to estimate C sequestration potential: 76?million?ha under silvopasture (25?million?ha or 10?% of pasture land and 51?million?ha of grazed forests), 15.4?million?ha (10?% of total cropland) under alley cropping, and 1.69?million?ha under riparian buffers. Despite data limitation and uncertainty of land area, these estimates indicate the important role agroforestry could play as a promising CO₂ mitigation strategy in the US and temperate North America. The analysis also emphasizes the need for long-term regional C sequestration research for all AP, standardized protocols for C quantification and monitoring, inventory of AP, models to understand long-term C sequestration, and site-specific agroforestry design criteria to optimize C sequestration.     

Seasonal variation of soil respiration rates in a secondary forest and agroforestry systems

Agroforestry systems are widely practiced in tropical forests to recover degraded and deforested areas and also to balance the global carbon budget. However, our understanding of difference in soil respiration rates between agroforestry and natural forest systems is very limited. This study compared the seasonal variations in soil respiration rates in relation to fine root biomass, microbial biomass, and soil organic carbon between a secondary forest and two agroforestry systems dominated by Gmelina arborea and Dipterocarps in the Philippines during the dry and the wet seasons. The secondary forest had significantly higher (p < 0.05) soil respiration rate, fine root biomass and soil organic matter than the agroforestry systems in the dry season. However, in the wet season, soil respiration and soil organic matter in the G. arborea dominated agroforestry system were as high as in the secondary forest. Whereas soil respiration was generally higher in the wet than in the dry season, there were no differences in fine root biomass, microbial biomass and soil organic matter between the two seasons. Soil respiration rate correlated positively and significantly with fine root biomass, microbial biomass, and soil organic C in all three sites. The results of this study indicate, to some degree, that different land use management practices have different effects on fine root biomass, microbial biomass and soil organic C which may affect soil respiration as well. Therefore, when introducing agroforestry system, a proper choice of species and management techniques which are similar to natural forest is recommended.     

A general classification of agroforestry practice

Present classification schemes confuse agroforestry practices, where trees are intimately associated with agricultural components at a field scale, with the whole farm and forest systems of which they form a part. In fact, it is common for farming systems to involve the integration of several reasonably discrete agroforestry practices, on different types of land. The purpose of a general classification is to identify different types of agroforestry and to group those that are similar, thereby facilitating communication and the organized storage of information. A new scheme is proposed that uses the ‘practice’ rather than the ‘system’ as the unit of classification. This allows an efficient grouping of practices that have a similar underlying ecology and prospects for management. A two stage definition of agroforestry is proposed that distinguishes an interdisciplinary approach to land use from a set of integrated land use practices. Four levels of organization are recognized through analysis of the role of trees in agricultural landscapes: the land use system, categories of land use within systems, discrete groups of components (trees, crops, animals) managed together, and functionally connected groups of such discrete practices in time and space. Precedents for this form of analysis are found in the literature and it conforms with generally accepted methods of systems analysis. Classification of major types of agroforestry practice proceeds primarily according to the components involved and the predominant usage of land. A secondary scheme further classifies these in terms of the arrangement, density and diversity of the tree components involved. This revised version was published online in June 2006 with corrections to the Cover Date.     

Contribution of trees to soil carbon sequestration under agroforestry systems in the West African Sahel

Consequent to recent recognition of agricultural soils as carbon (C) sinks, agroforestry practices in the West African Sahel (WAS) region have received attention for their C sequestration potential. This study was undertaken in the Ségou region of Mali that represents the WAS, to examine the extent of C sequestration, especially in soils, in agroforestry systems. Five land-use systems were selected in farmers’ fields [two traditional parkland systems, two improved agroforestry systems (live fence and fodder bank), and a so-called abandoned land]. Soil samples taken from three depths (0–10 cm, 10–40 cm, and 40–100 cm) were fractionated into three size classes (2,000–250 μm, 250–53 μm, and <53 μm) and their C contents determined. Whole-soil C contents, g kg⁻¹ soil, across three depths ranged from 1.33–4.69 in the parklands, 1.11–4.42 in live fence, 1.87–2.30 in fodder bank, and 3.69–5.30 in abandoned land; and they correlated positively with silt + clay content. Using the ¹³C isotopic ratio as an indicator of relative contribution of trees (C3 plants) and crops (C4 plants) to soil C, more tree-origin C was found in larger particle size and surface soil and indicated that long-term tree presence promoted storage of protected C in deeper soil. Existing long-standing agroforestry practices of the region such as the parklands seemed to have little advantage for sequestering additional C, whereas improved agroforestry practices such as live fence and fodder bank introduced in treeless croplands seemed to be advantageous.     

Agroforestry and the environment

Agroforestry is a traditional land use system that may contribute to the solution of environmental problems in agriculture. Agroforestry is the practice of deliberately integrating woody vegetation (trees or shrubs) with crops and/or animal systems to benefit from the resulting ecological and economic interactions. Recent research indicates that a wider adoption of agroforestry principles and practices is a key means by which the global agri-food sector might achieve more sustainable methods of food and fiber production by producing both economic benefits for farmers and environmental benefits for society. Agroforestry provides numerous provisioning, regulating, cultural and supporting ecosystem services and environmental benefits while promoting eco-intensification based on a more efficient use of the resources. Nevertheless, there is only little published recent information on the contribution of agroforestry to the environment in general and on climate change, carbon sequestration and forest fires in particular. In this special issue a number of articles are included that provide a kaleidoscope of the environmental benefits that agroforestry provides to the environment.

     

Global and European policies to foster agricultural sustainability: agroforestry

Agroforestry is a sustainable land management system recognized worldwide but not implemented in a extensive form in temperate and developed countries. Agroforestry has been promoted in the last decades at global level as it provides more efficient and sustainable farming systems. This review aims at summarizing the main research findings explaining why agroforestry is a sustainable land management that fulfils and is affected by different Global, Pan-European and European policies as well as how innovation is currently fostered in Europe, therefore linking research, policy and innovation. This review specially targets researchers and policy makers working in integrated land systems. There is a global and European recognition of the role that agroforestry can play to provide products but also to deliver highly important ecosystem services. However, the promotion of agroforestry practices at European level is still not well addressed by the Common Agricultural Policy. The clear identification of agroforestry practices, the link of management plans to establish agroforestry pursuing a final eligible tree density for the Pillar I payments should be addressed as initial steps to foster agroforestry in Europe. There is a lack of knowledge transfer that promotes agroforestry at field level, which should be approached by using stakeholder integration within the policy development as it is currently done by the EIP-Agri.

     

Agroforestry in the arid zones of India

The arid regions of India cover over 300,000 km² and are spread over six States, mostly in the northwestern parts of the country. In spite of the hostile environmental conditions, several indigenous agroforestry practices are being practised in this region. The Central Arid Zone Research Institute (CAZRI) has made considerable progress in improving these indigenous practices and also developing new land use technologies some of which involve agroforestry approaches. Notable among these include sand-dune stabilization, shelterbelt plantations, tree planting techniques in difficult land forms, silvopastoral and agrisilvicultural systems, introduction and improvement of fruit trees and other indigenous trees, etc. Some of these technologies are adopted on a large scale by farmers in the arid zone of India, and have attracted international attention in other arid parts of the world. This paper is a summary of the results of these agroforestry initiatives of CAZRI.     

Contribution of Small-Scale Agroforestry Systems to Carbon Pools and Fluxes: A Case Study from Middle Hills of Nepal

In view of the heavy people’s dependence (80 %) on various forms of land-based resources, carbon sequestration should not only be targeted in forests, but also on private land agroforestry. A survey was conducted in 2011 to investigate the gap in contribution of agroforestry carbon to the household economy in the middle hills region of Rasuwa district of Nepal. A total of 120 households were randomly selected and surveyed, of which eight were further examined for detailed tree carbon measurement. It is estimated that a total of 48.60 ton C per hectare has been stocked in agroforestry sites in the middle hills region. Assuming a carbon price of $US12/ton, the total potential income from carbon sequestration per household would amount to NPR 45,490/ha in 20 years of agroforestry if a payment scheme were introduced. The income from carbon sequestration is quite low compared with other agroforestry income. Policy implications are thus oriented towards farmers reaping multiple benefits from the existing international mechanisms by having negotiations based on contribution of all agroforestry components (farm trees, crops and animals) rather than limited to forest carbon stock. To benefit from these multiple functions of farms and forests, the policy framework to address the climate-related affects and risks (e.g., of landslides, burst of Himalayan lakes) should be broad enough to produce potential synergy between the negative effect of climate change and agroforestry income.     

The Bioeconomic Potential for Agroforestry in Australia’s Northern Grazing Systems

Although agriculture generates 16% of Australia’s greenhouse gas emissions, it also has the potential to sequester large quantities of emissions through land use management options such as agroforestry. Whilst there is an extensive amount of agroforestry literature, little has been written on the economic consequences of adopting silvopastoral systems in northern Australia. This paper reports the financial viability of adopting complementary agroforestry systems in the low rainfall region of northern Australia. The analysis incorporates the dynamic tradeoffs between tree and pasture growth, likely forest product yields, carbon sequestration and livestock methane emissions in a bioeconomic model. The results suggest there are financial benefits for landholders who integrate complementary agroforestry activities into existing grazing operations at even modest carbon prices.     

Integrating belowground carbon dynamics into Yield-SAFE,a parameter sparse agroforestry model

Agroforestry combines perennial woody elements (e.g. trees) with an agricultural understory (e.g. wheat, pasture) which can also potentially be used by a livestock component. In recent decades, modern agroforestry systems have been proposed at European level as land use alternatives for conventional agricultural systems. The potential range of benefits that modern agroforestry systems can provide includes farm product diversification (food and timber), soil and biodiversity conservation and carbon sequestration, both in woody biomass and the soil. Whilst typically these include benefits such as food and timber provision, potentially, there are benefits in the form of carbon sequestration, both in woody biomass and in the soil. Quantifying the effect of agroforestry systems on soil carbon is important because it is one means by which atmospheric carbon can be sequestered in order to reduce global warming. However, experimental systems that can combine the different alternative features of agroforestry systems are difficult to implement and long-term. For this reason, models are needed to explore these alternatives, in order to determine what benefits different combinations of trees and understory might provide in agroforestry systems. This paper describes the integration of the widely used soil carbon model RothC, a model simulating soil organic carbon turnover, into Yield-SAFE, a parameter sparse model to estimate aboveground biomass in agroforestry systems. The improvement of the Yield-SAFE model focused on the estimation of input plant material into soil (i.e. leaf fall and root mortality) while maintaining the original aspiration for a simple conceptualization of agroforestry modeling, but allowing to feed inputs to a soil carbon module based on RothC. Validation simulations show that the combined model gives predictions consistent with observed data for both SOC dynamics and tree leaf fall. Two case study systems are examined: a cork oak system in South Portugal and a poplar system in the UK, in current and future climate.     

Agroforestry for soil health

Healthy soil is one of the most critical resources for the health and sustainability of ecosystems, including agroecosystems. Although the agroforestry community has long been convinced of the soil health benefits of agroforestry practices, many of such practices remain to be fully accepted by the mainstream agriculture community. Agroforestry, as a sustainable land management practice, has shown solid evidence of its role in improving soil quality and health based on at least four decades of data gathered from the world over. This thematic issue presents 28 papers that add further to the body of knowledge to reaffirm that agroforestry can improve the major measurable soil metrics that define soil health. Collectively, these papers show that agroforestry has the ability to (1) enrich soil organic carbon better than monocropping systems, (2) improve soil nutrient availability and soil fertility due to the presence of trees in the system, and (3) enhance soil microbial dynamics, which would positively influence soil health. It is imperative that agroforestry, as part of a multifunctional land-use strategy, should receive increased attention in our policy discussion for the future of soil and soil health.     

Financial analysis of agroforestry land uses and its implications for smallholder farmers livelihood improvement in Ethiopia

A study was conducted in central highland Ethiopia to: (1) assess the financial feasibility and relative financial attractiveness of three agroforestry practices (small-scale woodlot, homestead tree and shrub growing and boundary tree and shrub growing); (2) evaluate the impacts of implementation of these land uses on farm households income and (3) identify the constraints for the implementation and expansion of the agroforestry practices. Then, 82 different land uses (21 small-scale woodlots, 35 homesteads and 26 boundary plantings) which were older than 15 years and established by the current owner were selected for the financial analysis. The input and output data were filled in a data sheet by face-to-face interview with the owners. The results showed that small-scale woodlot is the most profitable agroforestry practice followed by boundary plantings and homesteads. An ex-ante analysis of implementing the agroforestry practices showed that with minimum land area allocated for the practices, a household can generate net discounted revenues ranging from 5,908 to 26,021 Ethiopian Birr (532–2,342 USD) in 15 years at 10 % interest rate. Hence, the expansion of such agroforestry practices has a vital effect on farm household’s income. Lack of proper planning and poor in-depth understanding about roles of trees and shrubs for household’s income, land and seedling shortage, financial constraints and labor scarcity were identified as major problems for the expansion of agroforestry practices in the area. A thorough extension service comprising both efficient land resources utilization and proper planning practices could enhance the expansion of agroforestry practices and thereby positively influence the farmer’s livelihood.     

Agroforestry practices in Nigeria

The problems of too much pressure on land for the production of food and wood for the increasing population have made it mandatory to look into the various ways of maximising the uses of agricultural land in different parts of the world. Under this high demand for land, the system of shifting cultivation which has been practised from time immemorial can no longer support the needs of farmers in Nigeria. As a result of this, the different agroforestry practices have received increased attention. The experiences obtained with shifting cultivation, homestead gardens, taungya, alley-farming and scattered farm tree methods including shelterbelt planting in the country are reviewed in this paper and some research findings on these practices are highlighted.     

Assessing agroforestry adoption potential utilising market segmentation: A case study in Pennsylvania

In the United States, agroforestry adoption has lagged behind progress in agroforestry systems research. This study sought to facilitate the communication of landowner land management objectives, values, knowledge and perceptions of the barriers and benefits to agroforestry through applied social marketing research methods and market segmentation analysis. A mail survey instrument was sent to 250 members of the Pennsylvania Association of Sustainable Agriculture (PASA) and 250 members of Woodland Owner Associations (WOA). Current management objectives and production strategies, agroforestry awareness, agroforestry interest, and perceptions regarding the benefits and obstacles to agroforestry adoption were gauged. Market segmentation was performed with a two-step cluster analysis to produce four agroforestry adoption potential models: Timber-Related Practices, Livestock-Related Practices, Specialty Crop-Related Practices, and Non-Adopters. The analyses showed that agroforestry practices could satisfy specific land management objectives within diverse populations. The method effectively identified similarities in agroforestry adoption scenarios. Market segmentation could be utilised as a social marketing tool to guide future policy development, scientific research, and the efficacy and relevance of future agroforestry research and outreach programs. The next step in program development should include the creation of a statewide multidisciplinary team comprised of university, non-profit association and landowner representation, to develop agroforestry applications relevant to each cluster and promote the practices through landowner-led on-farm demonstrations and workshops.     

农林复合系统对世界林业发展的影响

介绍了农林复合系统的起源、含义和研究初始阶段存在的问题,阐述了农林复合系统对世界林业发展的促进及其发展趋势,同时,概述了农林复合系统在土地可持续利用方面的显着特征、适用范围和主要优势。     

Carbon in Terrestrial Systems

Abstract

This analysis reviews the state of the knowledge regarding carbon sequestration in terrestrial biomass with specific focus on tropical systems in Central America and Panama. Natural forests, exotic plantations, native species plantations, and agroforestry systems are considered in light of their carbon sequestration potential, their initiation and maintenance costs, and their ability to access the emerging regulated and informal carbon markets. All four of these systems show great potential to take up or store carbon and thus contribute to atmospheric reductions of C0₂. Research, investment, and institutional support are required to assist in the clear definition and expansion of carbon supply possibilities for market transactions.     

Factors constraining and enabling agroforestry adoption in Viet Nam: a multi-level policy analysis

Agroforestry is known to have multiple economic and environmental benefits. Despite this, the adoption of agroforestry in Viet Nam is limited both in extent and diversity of components and practices. Our study identified gaps for agroforestry adoption in current policies and policy implementation. National policy and provincial instructions and decisions were reviewed and discussed during ten stakeholders’ consultation workshops. The review and workshops concluded that there were no specific national and few provincial specific policies promoting agroforestry. In addition, the segregation of policies into agriculture and forestry, promoted monoculture practices and discouraged the integration of mixed annual and perennial tree species. Completing the forestland allocation process was considered essential for long-term investment on land and providing collateral for loans. More holistic policies, such as a provincial strategy for agroforestry development that would enable flexible integration of agriculture, forestry and livestock were perceived to be more effective and inclusive to poor and non-poor farmers. Specific cross-cutting budget allocation would be necessary for capacity building, upscaling agroforestry models, procurement of high-quality inputs, and establishing post-harvest processing and marketing investments.     

Agroforestry in Europe: a review of the disappearance of traditional systems and development of modern agroforestry practices, with emphasis on experiences in Germany

Agroforestry is a new name for a rather old practice. From a historical point of view, various agroforestry systems existed in Europe, of which the wood pastures (Neolithicum), the Dehesas in Spain (~4,500 years old) and the Hauberg of the Siegerland (established in the Middle Age) are the most prominent. Other widespread systems in Europe were hedgerows, windbreaks and Streuobst (orchard intercropping). Due to mechanisation and intensification of agriculture, trees have been progressively removed from agricultural fields and traditional agroforestry systems slowly disappeared. Today, agroforestry systems are again increasing in interest as they offer the potential to solve important ecological and, especially, biodiversity problems, while at the same time enabling the production of food, wood products and fodder for cattle. Although agroforestry systems offer many advantages, many farmers are sceptical of these systems and are critical and risk-averse with regard to adopting new practices. However, in comparison to traditional systems, modern agroforestry systems can be adapted to current farming practices. By selecting suitable trees and appropriate tree management, high-quality timber can be produced without influencing agricultural crops excessively. In future, agroforestry systems will become increasingly important as they offer the prospect of producing woody perennials for bioenergy on the same land area as food and/or fodder plants, while enhancing overall biodiversity.