Using a Logistic Regression Model to Analyze Alley Farming Adoption Factors in Sierra Leone

Slash-and-burn shifting cultivation is the conventional farming practice in Sierra Leone, where communal land tenure is by far the most common form of land use. Alley farming, the alternative agricultural system, has been introduced as a technical option to increase yield, reduce or eliminate fallow and conserve soil water. This study uses a logistic regression model to determine the factors influencing the adoption of alley farming in Sierra Leone. Data for the study were collected from a total of 160 farmers in 16 farming communities across 4 ecotones in the Freetown Peninsula through a survey, interactive discussion and personal observation. It is found that although most of these communities are aware of alley farming, female farmers are less likely than males to adopt this farming technology. Also membership of farmers’ associations and access to extension services positively influences adoption of alley farming, but limited land availability hinders adoption in the region. Most of the farmers practicing or trying out alley farming prefer this farming system over slash-and-burn shifting cultivation. High demand for fuelwood, short or no fallow periods and replenishment of soil fertility are among the attributes driving farmers to switch to alley farming. Despite its merits, alley farming is not perceived as a complete substitute for slash-and-burn shifting cultivation in the study area. For wider adoption, there is the need to develop demonstration farms to show the feasibility of incorporating farmer-specific biophysical, hydro-climatic and socio-economic conditions into alley farming system in the region.     

The Effects of Household Asset Endowments on Agricultural Diversity among Frontier Colonists in the Amazon

This paper focuses on agricultural diversity, a key property of agroforestry systems, and examines the influences of household asset endowments. The analysis addresses a debate between ‘differential motivation’ and ‘ differential capacity’ arguments concerning the importance of asset inequality for agricultural diversification among rural households in developing regions. I draw on data from a survey of small farm colonists in the Brazilian Amazon to assess components and measures of agricultural diversity, and to model those diversity measures using indicators of household asset endowments. The results indicate that agricultural diversification is modest in the study site, but varies among households, as do asset endowments. Models of agricultural production and income diversity indicate that agricultural diversity primarily reflects labor endowments, though certain types of capital are also important. These findings bear implications for research on agricultural diversity in other contexts, and for policies aiming to promote ‘productive conservation’ by compatibilizing poverty reduction, economic development and environmental sustainability.     

Organic carbon pools in a Luvisol under agroforestry and conventional farming systems in the semi-arid region of Ceará, Brazil

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 Ceará, 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 Ceará state.     

Coffee agroecosystem performance under full sun, shade, conventional and organic management regimes in Central America

Changes in coffee economics are leading producers to reduce agrochemical use and increase the use of shade. Research is needed on how to balance the competition from shade trees with the provision of ecological services to the coffee. In 2000, long-term coffee experiments were established in Costa Rica and Nicaragua to compare coffee agroecosystem performance under full sun, legume and non-legume shade types, and intensive and moderate conventional and organic inputs. Coffee yield from intensive organic production was not significantly different from intensive conventional in Nicaragua, but in Costa Rica it was lower during three of the six harvests. Full sun coffee production over 6 years was greater than shaded coffee in Costa Rica (61.8 vs. 44.7 t ha^?1, P = 0.0002). In Nicaragua, full sun coffee production over 5 years (32.1 t ha^?1) was equal to coffee with shade that included Tabebuia rosea (Bertol.) DC., (27?C30 t ha^?1) and both were more productive (P = 0.03) than coffee shaded with Inga laurina (Sw.) Willd. (21.6 t ha^?1). Moderate input organic production was significantly lower than other managements under all shade types, except in the presence of Erythrina poepiggina (Walp.) O.F. Cook. Inga and Erythrina had greater basal area and nutrient recycling from prunings than other shade species. Intensive organic production increased soil pH and P, and had higher K compared to moderate conventional. Although legume shade trees potentially provide ecological services to associated coffee, this depends on management of the competition from those same trees.     

Productivity and profitability of multistrata organic versus conventional coffee farms in Costa Rica

In areas where traditional multistrata coffee systems have been transformed to systems with patchy or no shade at all, often dependent on high chemical inputs, ecological and socioeconomic degradation has become an increasing issue. During the 1990s, rising environmental and health concerns have promoted the interest in organic production systems and their environmental services for natural resource conservation. This study compared productivity, profitability, producer-defined constraints, and goals and research priorities between ten individually paired organic and conventional coffee farms in Costa Rica. Although five of the organic farms matched or exceeded the production of their conventional counterparts, the three-year mean yield of the organic farms as a group was 22% lower than that of the conventional farms. However, excluding organic certification costs, mean variable costs and net income (NI) were similar for both groups, mainly because organic price premiums received by the farmers compensated for lower yields. If current organic certification costs are included, the price premiums paid to organic producers would have to increase to 38% in order to equal the NI from conventional coffee. Conventional farmers indentified low and unstable prices as the main constraints to sustained production and stated further intensification of production as their main goal. In contrast, the key issues for future development of the organic group centered on farm diversification, agroecological self-sufficiency, and agronomic practices that permit organic farm management. This revised version was published online in June 2006 with corrections to the Cover Date.     

Farmers’ Motivations to Plant and Manage On-Farm Trees in Ghana

Deforestation and forest degradation, especially in the agricultural landscapes, are serious threats to biodiversity conservation and sustainability of the timber industry. Planting trees on farms has been identified as having great potential to increase forest resources from agricultural landscapes. This paper examined farmers’ motivations and behaviour to engage in on-farm tree planting and management in Ghana by combining internal and external factors in a socio-psychological model. Data were collected from 156 smallholder farmers from five communities in two forest districts using a semi-structured questionnaire. Additional farm inventory data were collected from 33 farmers under two on-farm tree planting schemes. On-farm tree planting was perceived as providing income, access to personal timber for furniture, and access to loan facilities. Incentives such as provision of grants, farming inputs, capacity training, and access to markets for agricultural produce are factors that motivate on-farm tree planting in Ghana. The average standing volume of on-farm trees in the study area is 51.9 m³/ha which is almost twice the national average for the off-reserve areas in the semi-deciduous forests to which much of the study sites belong. Many farmers considered high financial costs and limited knowledge of appropriate techniques in managing planted on-farm trees as barriers to the development of tree stock on farms.     

Effects of contour hedgerows on water and soil conservation,crop productivity and nutrient budget for slope farmland in the Three Gorges Region (TGR) of China

Soil erosion has long been recognized as a major environmental problem in the Three Gorges Region (TGR) where slope farming is commonly practiced but the local topography is hilly. In consideration of the poor socioeconomic position of local farmers, low cost hedgerows had been introduced as a soil conservation measure to the TGR in the late 1980s. A collaborative research programme was initiated by the Chinese University of Hong Kong, the Chinese Academy of Science, the Huazhong Agricultural University, and the Bureau of Soil and Water Conservation of Zigui County to study the potential of adopting hedgerows in the TGR. Six experimental plots (10 m × 2 m, gradient = 25°) were constructed at Zigui County, Hubei Province to study effects of hedgerows on erosion, nutrient loss and crop productivity. Results indicated that there were significant relationships between rainfall and runoff, and rainfall and soil loss, respectively. Conventional slope farming could not be considered a sustainable agricultural practice because it resulted in severe erosion and low crop yield. Hedgerows per se seemed not to be effective in reducing soil loss and boosting crop productivity, but performances could be greatly improved when they combined with the use of fertilizers. Current farming and fertilization practices, however, generally did not meet N demands of crops. Results and findings of this paper will contribute towards a technical reference for the promotion and adoption of hedgerows in the TGR.     

Alley cropping—soil productivity and nutrient recycling

In the past few decades there has been growing concern about the exhaustibility of non-renewable soil resources in developing countries in the tropics to meet the needs of present and future generations. Land degradation is a major problem in many parts of the tropics, including subSaharan Africa, mainly owing to overexploitation of vegetation and soil resources and adoption of inappropiate farming methods. The challenge is to increase the sustainable agricultural productivity of the land with acceptable inputs to meet increasing human needs, while maintaining the soil resource base and minimising environmental degradation. One technology that can meet this need for rainfed upland farming with low external chemical inputs is the alley cropping system. This technology integrates trees and shrubs in spatial zonal arrangements with food crops in the production system. The presence of woody species in the alley cropping production system has been shown to contribute to (1) nutrient recycling, (2) reduction in soil nutrient leaching losses, (3) stimulation of higher soil faunal activities, (4) soil erosion control, (5) soil fertility improvement and (6) sustained levels of crop production. These experiences can be utilised in developing sustainable and environmentally friendly agroforestry systems.     

Evolution of agroforestry based farming systems: a study of Dhanusha District, Nepal

This paper examines how agroforestry-based farming systems evolved in the Dhanusha district of Nepal following the conversion of forest into agriculture during the early 1950s. Some data are from two focus group discussions with agroforestry farmers and one meeting with agroforestry experts. The farmers?? discussion traced the development of farming practices from 1950 to 2010 to identify the drivers of land use change. The experts?? discussion resulted in a scale to differentiate the prevailing farming systems in the study area considering five key components of agroforestry: agricultural crops, livestock, forest tree crops, fruit tree crops and vegetable crops. Data related to the system components were collected from the randomly selected households. The study reveals that land use had generally changed from very simple agriculture to agroforestry, triggered by infrastructure development, technological innovations, institutional support (subsidies and buy-back guarantees) and extension programs. A range of farming systems with varying degrees of integration was evident in the study area: simple agriculture; less integrated agroforestry; semi-integrated agroforestry and highly integrated agroforestry. The three types of agroforestry systems, which are the focus of this study, varied significantly in terms of farm size, cropping intensity, use of farm inputs, tree species diversity, tree density, home to forest distance and agricultural labour force.     

Drivers of adoption of eucalypt tree farming by smallholders in Thailand

Eucalypt (Eucalyptus spp.) tree farming is a source of income for many smallholders in developing and emerging countries and critical to the resource supply of many pulp and paper companies. These companies rely on smallholders adopting tree farming, sometimes by offering a contract. This paper reports a study from four regions of Thailand, where smallholder eucalypt tree farming is important, which investigated what characteristics of smallholders were associated with greater adoption of tree farming. A total of 461 eucalypt tree farmers and 171 non-tree farmers were randomly selected and surveyed in these regions, using a door-to-door household survey. A logit analysis corroborated hypotheses about the drivers of adoption. Qualitative analyses were used to inform interpretation of the quantitative results and shed light on the role of eucalypt tree farming in smallholders’ livelihood. Results demonstrate that those with suitable land available are more likely to adopt eucalypt tree farming than others. In addition, perception of land tenure security matters in the adoption of tree growing, but holding a formal land tenure document does not. Adoption of eucalypt tree farming in Thailand is not part of a land use intensification strategy. Instead, eucalypts are used as an alternative crop for low productivity land, on which eucalypts are the most profitable crop. Eucalypt tree farming also gives smallholders an opportunity to diversify their income. In addition, this alternative land use has the advantage of requiring low labour inputs between planting and harvest. This is particularly advantageous for many tree growers who have off-farm income or rely on hired labour for farming their land.     

Farm Forestry Prospects Among Some Local Communities in Rachuonyo District,Kenya

Deforestation and degradation of productive lands are serious threats to the sustainability of forestry/agricultural practices in Kenya. In the last two decades farm forestry (FF) has been promoted through pilot projects among local communities as an example of sustainable land use. However adoption of FF is limited outside the project locations because FF improvement measures focused mainly on biological (e.g. succession, biodiversity and traditional industrial timber production) and technical concerns (e.g. material input delivery such as providing free tree seedlings for field planting) rather than local values, and interests and the constraints facing farmers. This study examined the local farm priorities and constraints and the prospects for the wider implementation of farm-level tree planting in four communities in Rachuonyo District. Using interviews with 597 randomly selected household heads, the study assessed farmer’s production assets and activities, land tenure, priority tree species and the constraints to growing trees on farms. Results show that farm labour is represented by a young population, 56.3% under the age of forty. They are mainly engaged in small-scale mixed cropping integrated with multipurpose trees and some livestock. Tree products contribute about 32% to household cash income, more than any other source (agricultural products, labour sales, etc). Females were more often household heads and had considerable influence over productive activities, making them an important target group in FF development. Farmers preferred exotic tree species due to their ability to provide short-term cash income, fuel and shade. Farmers’ concerns included population pressure on limited farmlands and the problem of credit for agricultural inputs. Given the feeling of secured tenure arrangement and influence of tree products on the household economy, farmers are likely to invest more in efficient land uses such as FF if consideration is given to local priorities.     

Commercialization of homegardens in an Indonesian village: vegetation composition and functional changes

We examined structural and functional changes in the homegardens of Sukapura village, located in the upper Citarum Watershed of Indonesia, in relation to the increasing commercialization of agriculture. Our main purpose was to examine the structure and function of these homegardens during the rapid economic development of this area and the ecological, social, and economic implications of changes. A standard vegetation survey was used to describe the compositional and structural patterns of vegetation in the sampled homegardens, and interviewed 94 randomly selected respondents to help us understand the functions of their homegardens. The results suggest that commercialization in the agricultural sector has changed the structural patterns and functions of these homegardens. Plant diversity in commercialized (intensively managed) homegardens has decreased owing to the use of monocultures. The change from subsistence towards commercial farming has been accompanied by decreased plant diversity, higher risks, higher external inputs, increased instability, and reduced social equitability. The specific needs and preferences of the owners and market pressures were the main factors that triggered the development of intensive agriculture in the study area, leading to increased commercialization of homegardens.     

Determinants of farmers' adoption and adaptation of alley farming technology in Nigeria

Understanding the factors affecting framers' adoption of improvedtechnologies is critical to success of implementing agroforestry developmentprograms. This paper evaluated the determinants of farmers' decisions to adoptand adapt alley farming technology and its variants in the farming systems ofNigeria, using econometric Logit models. Eleven variables were significant inexplaining farmers' adoption decisions. The model results show that farmercharacteristics that influenced adoption included the gender of the farmer,contact with extension agents, years of experience with agroforestry and tenancystatus in the village. Economic factors, proxied by village-levelcharacteristics that condition resource use incentives, were also significant.These variables include the extent of village land pressure, extent of erosionintensity, village fuel wood pressure, importance of livestock as an economicactivity in the village and the distance of the village locations from urbancenters. The paper showed that farmers are already making significantmodifications to the conventional alley farming technology introduced byscientists. The two most important modifications were the introduction of fallowperiods into the conventional system and changes in the pruning regime of thesystem. Model results showed that human capital variables were significant inexplaining farmers' decisions to adapt and modify the technology. Farmereducation and family size significantly influence the choice of pruning regime.Farmers' age, education, intensity of erosion in the farmers' village, andfarmers' land availability significantly influence whether or not fallowperiod is introduced into the conventional system. To promote greater adoptionof agroforestry alternatives to slash-and-burn agriculture, particular attentionshould be placed on the use of appropriate socioeconomic characterization, tobetter target technologies to areas with higher adoption potential. This revised version was published online in June 2006 with corrections to the Cover Date.     

Agroforestry farming systems in the homesteads of Kerala,southern India

Kerala State on the southwestern coast of India in the tropical humid zone has a predominantly agricultural economy, a very high density of population and therefore high pressure on cultivable land. The farmers there undertake cultivation of an array of crops — tree crops, plantation crops, seasonals and biennials — all in intimate mixtures on the same piece of land around the homesteads. Farm animals and poultry and sometimes fisheries also are essential components of the system. The close association of agricultural crops, tree crops and animals in the homesteads represents an excellent example of sustainable and productive agroforestry homegardens. Optimum utilization of available resources of land, solar energy and technological inputs and an efficient recycling of farm wastes are important characteristics of the systems. This paper attempts to describe and evaluate the systems' stability, productivity and sustainability, and identify its merits and constraints as well as research needs.     

Sustainable Management of Forests for Atmospheric CO2 Depletion

Abstract

The topic of forest sector carbon balance in connection with climate changes currently has both great scientific and political importance for ecological sustainability on a global scale. The concentration of CO2 in the atmosphere has increased by 1-2 ppm per year in the last few decades. The present paper examines the actual and potential role of forest management to deplete atmospheric CO2 concentration, with specific reference to the Italian situation as a case study. Italian carbon emission derived from fossil fuels amounts to 432 Mt/year, of which 65% comes from burning oil. Annual CO2 absorption, estimated by combining the 1985 National Forest Inventory data with selected biomass data, proves to be quite relevant, amounting to more than 10% of the annual Italian CO2 emission. This is a prudent estimate, since no account is taken of the contributions of non-tree vegetation and soil. Current forest management standards are mainly oriented to conservation. Optimisation of forest management specifically purposed also to carbon storage and non-wood products substitution may further enhance the role of Italian forest sector for atmospheric CO2 depletion: in such a view, practical issues (amelioration of existing forest stands; adjustment of harvesting yield to the actual production capacity of forest stands and adjustment of production standards towards high durable wood products; afforestation and tree cropping by means of changes in land use) are addressed within a sustainability framework.     

Implications of local policies and institutions on the adoption of improved fallows in eastern Zambia

Planted-tree fallows (syn. improved fallows) have demonstrated great biophysical potential for improving soil fertility on smallholders' farms but efforts to scale up their adoption to more farming households are constrained by lack of permanent ownership rights over land, incidence of bush fires and browsing of tree biomass by livestock. To resolve these institutional bottlenecks, some traditional authorities in Zambia enacted bylaws to prohibit these incursions. Using a combination of village workshops, expert opinion surveys and structured questionnaires, this study assessed the effectiveness of the bylaws across the major cultural communities in eastern Zambia, identified factors that influence the effectiveness of the bylaws and the lessons emanating from the bylaws in the scaling up of improved fallows. The results indicate that fire poses greater risks to the scaling up of agroforestry than does grazing in terms of the risk of occurrence and the extent of damage. Respondents identified mice hunters and `jealous' neighbors as main causes of fire outbreaks. The effectiveness of the bylaws is influenced by many factors such as ambiguous interpretation of the bylaws, relying exclusively on moral persuasion to enforce the bylaws and lack of well defined responsibilities for enforcing the bylaws, conflict of economic interests among different stakeholders within the communities. Formal documentation of the bylaws will be helpful, but that would not be an exclusive panacea to solve all the constraints. The pattern of distribution of benefits (or costs) of an agricultural technology among various sectors of a community may be important factors that affect widespread adoption of a technology. Technological characteristics are important but not exclusive condition for sustained widespread adoption of soil fertility management options. Privatizing seasonal commons is an important issue in the development of institutional regulations within communities. Policy dialogue among community members, increased awareness and diversification of options appear to be the way forward to improve the effectiveness of the bylaws. This revised version was published online in June 2006 with corrections to the Cover Date.     

Agricultural intensity and its measurement in frontier regions

Agricultural intensification is a process of raising land productivity over time through increases in inputs of one form or another on a per unit area basis. Its study is important for several reasons, many of which relate to agroforestry objectives. However, the concept of intensification often is poorly defined in the literature and existing methods and approaches to measuring agricultural intensity are problematic, making it difficult to precisely compare particular farming systems. This paper examines the concept of agricultural intensity, its relevance to efficient and sustainable land use, and the ways it can be measured. A review of existing approaches and methods for measuring intensity, such as those based on output, cropping frequency, and agrotechnologies, revealed that these feature a number of problems. Some of these problems relate simply to imprecision and inaccuracy. But others are due to the unsuitability of these approaches in the context of farming environments, such as frontiers, which are characterized by limited production data; unconventional cropping cycles; myriad production strategies, cropping patterns, and crop-fallow cycles on a single farm; and a high level of system dynamism and production variability over time. A modified approach to measuring agricultural intensity, based on fieldwork in Petén, Guatemala, is presented. This approach, which is better suited to frontier regions, employs an agricultural intensity index to help evaluate the intensity of particular farm units based on the technologies and practices used by the farmer, and the degree to which they are used.This revised version was published online in November 2005 with corrections to the Cover Date.     

Adoption of riparian forest buffers on private lands in Nebraska, USA

Pesticide and nutrient runoff from agricultural fields is a socio-environmental problem in the Midwestern United States. Riparian forest buffers (RFBs) are a proven conservation practice that effectively manage this problem, though adoption rates are low. A mail survey was conducted to determine differences between adopter and nonadopter characteristics and attitudes with regard to the use of RFBs. Data were collected from 48 RFB adopters and 261 RFB nonadopters in two Nebraska watersheds. Inferential and multivariate statistics were used to identify differences between adopter status and producer status groups. About half (50.8%) the respondents were nonproducers. Nonproducers are agricultural landowners not farming that make decisions about whether to install conservation practices on their land. Among the adopter respondents, non-farming agricultural landowners (nonproducers, n=25) were as likely to adopt RFBs as producers (n=23). Adopters were more informed about RFBs and willing to accept government payments. Receiving technical and financial assistance was a major key to adoption. The research has identified important opportunities for more effective and targeted RFB extension education programming.     

Household decision-making in agroforestry parklands of Sudano-Sahelian Mali

This study examines farmers’ knowledge and management of soil fertility and vegetation in Vitellaria paradoxa and Cordyla pinnata dominated agroforestry parklands in a Sudano-Sahelian region of Mali. Qualitative data from a series of semi-structured interviews were used to construct an empirically based typology of farmer practices. These interrelated practices center on famers’ agroecological knowledge, decision-making, and cropping strategies and are conceptualized as variable and adjustable socioecological responses to environmental and socioeconomic contingencies. The typology categorizes farmers in terms of their capacity for managing parkland soil and tree resources in an ecologically sustainable manner while negotiating livelihood challenges. It identifies the ideal farmer as one who practices the following: (1) use of environmental knowledge that considers multidimensional relationships among ecological and social components of parkland systems, (2) agricultural techniques that adaptively combine aspects of intensive and traditional extensive agriculture, and (3) natural resource decision-making that explicitly includes women’s environmental knowledge and livelihood strategies.     

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.