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.     

Performance of an improved fallow system in the Peruvian Amazon—modelling approach

As traditional slash-and-burn systems with prolonged fallow periods are no longer feasible in most parts of the tropics, improved agroforestry systems have high potential to increase the productivity of farming systems and sustain continuous crop production. Our objective was to assess biophysical and economic performance of planted leguminous tree fallow (using Inga edulis) compared to the traditional slash-and-burn farming system, practiced by farmers on fields infested with noxious weedy grass Imperata brasiliensis around the city of Pucallpa, Peru. An existing agroforestry model SCUAF was used to predict biophysical factors, such as changes in soil characteristics and farm outputs (crop and tree yield). While a cost–benefit analysis spreadsheet, which uses the output from SCUAF and economic data on input/output levels and prices, calculates economic performance of the systems. The Inga fallow system can provide improvements to a range of soil biophysical measures (C, N, P content). This enables higher levels of farm outputs to be achieved (higher cassava yields). However, for smallholders the improved system must be more economically profitable than the existing one. At prices currently encountered, the Inga fallow system is more profitable than the Imperata fallow system only in the long-term. In adopting the Inga fallow system, smallholders will incur lower profits in the first years, and it will take approximately 10 years for smallholders to begin making a profit above that achievable with the Imperata fallow system. Unless smallholders are capable of accepting the lower profitability in first years, they are less likely to adopt the new system.     

Implications of national land legislation and customary land and tree tenure on the adoption of alley farming

Increasing population in the forest zone of Cameroon has led to reduction of fallow periods and to diminution of per capita cropping land area. Alley farming is a promising technology for the zone; however, its large scale adoption depends on host of factors of which an important one is tree and land tenure. For this reason, a study was conducted in 1990 to determine implication of national land legislation and customary land and tree tenure on the adoption of alley farming in the forest zone of Cameroon.Despite national laws purposing to regulate land and tree use, ownership rights to land and trees are largely determined by customary tenure rules. According to the forest zone customs, land is passed on from father to son when the father dies. Owners of inherited lands have full rights on lands and these rights are rarely revoked. Women do not own lands but are allowed to crop any piece of their husband's land as long as they stay married. Despite the lack of land ownership, women might still readily adopt alley farming because they are primarily concerned about food crop production and the amount of land to be given to their sons in the future.Study funded by the International Livestock Center for Africa (ILCA), Addis-Abeba, Ethiopia, and technically supervised by the Land Tenure Center (LTC), University of Wisconsin, Wisconsin USA.     

Factors affecting the adoption of agroforestry practices by farmers in Cameroon

This paper presents empirical evidence on the impact of socio-economic factors on the adoption of agroforestry practices in Cameroon. The analysis uses primary farm-level data collected from June to December 1996. Three major provinces of the country were covered, namely Centre, Southwest and Northwest Several agroforestry technologies have been promoted among farmers in the zone, including alley farming, improved fallow, live fencing, cut-and-carry fodder and apiculture. The status of adoption of each agroforestry practice is described and factors that affect adoption identified. These are gender of farmer, household family size, level of education, farmer’s experience, membership within farmers’ associations, contact with research and extension, security of land tenure, agroecological zone, distance of the village from nearest town, village accessibility and income from livestock. Research findings indicate that since factors affecting farmers’ adoption of agroforestry practices differ across techniques, generalisation is to be avoided.     

Mechanized land preparation in forest-based fallow systems: The experience from Eastern Amazonia

Agroforestry Systems - The slash-and-burn practice of land preparation that farmers use traditionally in forest-based fallow systems in the humid tropics causes land degradation and human health...     

From alley cropping to rotational fallow: Farmers' involvement in the development of fallow management techniques in the humid forest zone of Cameroon

Alley cropping was introduced in the humid forest zone of Cameroon to increase soil fertility in 1987, but until 1992 the adoption rate had remained low. To better understand the reasons behind this, three types of on farm trials were established from fully researcher controlled to fully farmer controlled. During the evaluation of the technology with farmers a number of modifications were registered (1) Pruning height and frequency: Because of the difficulties to consistently cut back at 30 cm, farmers decided to slash at ground level as they normally do while slashing the natural fallow vegetation. This equally allowed for more flexibility in time of pruning. (2) Cropping intensity and pattern: Initially, alleys were cropped each year. This however had several shortcomings. Having observed the positive impact of incidental fallow period in a farmer's field, it was decided to introduce a fallow phase of at least one year. During the fallow period the plot can be used for fodder production, bee farming and production of stakes. (3) Residue management: Fire went incidentally in a farmer's tree plot after slashing, and the trees were not affected. This gave farmers an alternative way to manage the residue, by controlling the fire, before bringing in other crops such as groundnut and cassava. (4) Agroforestry species: Because Leucaena leucocephala, in spite of it soil fertility restoration potential, rapidly became a noxious weed, farmers have asked for a less invasive species. Calliandra calothyrsus was introduced for this purpose and became a good bee forage. With these modifications, the original alley cropping system has evolved into a rotational tree fallow with higher adoption potential. From about 15 farmers who were testing the technology in 1992, the number increased to 52 in 1996, 120 in 1997 and 236 in 1998. This revised version was published online in June 2006 with corrections to the Cover Date.     

Pasture or permanent crops after slash-and-burn cultivation? Land-use choice in three Amazon colonies

Land use was examined in three settlements – Pedro Peixoto in Acre and Theobroma in Rondonia, Brazil, and Pucallpa, in Peru. Research aimed at characterizing the differences in land use after initial slash-and-burn, and presenting hypotheses to assess the feasibility of improved land uses. Settlers in the Amazon practice slash-and-burn agriculture in forest lands to produce annual crops. After cropping, lands are converted to pasture, or planted with perennial crops, or fallowed in anticipation of future annual crop production. Land use after slash-and-burn cultivation in forest lands differed among the colonies examined. Whereas colonists in Pedro Peixoto converted lands to pasture for cattle production, settlers in Theobroma adopted a strategy encompassing both dual-purpose (milk and meat) cattle and perennial crop production. The more heterogeneous settlers in Pucallpa, who included small-scale cattle ranchers and riverine and forest slash-and-burn farmers, gave more importance to perennial crops. Hypotheses are suggested regarding the described land use differences, and implications for the adoption of agroforestry are discussed. This revised version was published online in June 2006 with corrections to the Cover Date.     

Personal preferences and intensification of land use: their impact on southern Cameroonian slash-and-burn agroforestry systems

Where long forest-fallows are no longer practiced, productivity declines in the absence of input substitution, as does the ability of subsistence farmers to earn an adequate livelihood from shifting cultivation. Land availability, population density and productivity-related factors such as soil fertility and labour requirements are not the only factors that affect fallow length and land use intensification in shifting cultivation agroforestry systems. Households surveyed indicated that various other decision criteria (e.g., proximity to other fields and the protection of land use rights) are important in land use decisions. Even though one quarter of households reported insufficient land resources to maintain soil fertility, few actually indicated that their choices were constrained by land availability. In fact, many cleared much younger fallows than strictly necessary based on the age of fallows available in their land holdings – even those with fallows of sufficient age to maintain long-term productivity. This paper outlines an approach to quantify information about the household preferences that influence land use decisions, discusses the implications of these decision criteria for land use intensification and uses them to model household decision-making in a way that effectively simulates the spatial and dynamic mosaic of land use characteristic of shifting cultivation. Not only are non-productivity related decision criteria important in land use decisions in general; they also have a significant impact on land use intensification. In fact, the research described here demonstrates that both household-specific preferences and household-specific initial conditions can lead to intensification of land use apart from that arising due to increasing population density.     

Soil organic carbon status and sustainability of slash-and-burn cultivation in India

ABSTRACT

The study was carried out (a) to identify the changes in the soil organic carbon (SOC) content during the different phases of slash-and-burn cultivation—i.e., before slash-and-burn (Phase 1), after slash-and-burn (Phase 2), and after harvest (Phase 3); and (b) to determine the status of soil organic carbon content in the primary undisturbed forest (Site 1) and in the secondary forests, where slash-and-burn cultivation was taken up ~25 yr (Site 2), 15 yr (Site 3), and 5 yr back (Site 4). The undisturbed forest holds the largest amount of SOC % (5.25) followed by 25 yr (3.07), 5 yr (2.86), and 15 yr (2.27) fallow. The mean percentages of SOC in the 0- to 15-cm layer fell from 3.07 in Phase 1 to 2.53 and 2.37, respectively, in Phases 2 and 3; in the subsurface 15- to 30-cm layer, they fell from 1.95 to 1.62 and 1.63, respectively. Although, the SOC in Phase 3 still seems sufficient to support another round of cultivation, further studies are needed to examine crop yields in successive cultivation cycles, suitability of other rice varieties, and weed and pest types and rates of invasion. Tribal population dynamics is another major concern, which needs assessment for monitoring future land requirements.     

固氮树木与混农林系统

简述了固氮树木应用于混农林系统的研究发展过程,总结了目前所采用的主要模式,并列举了常见的、重要的固氮树木种类.     

Introducing Cash Crops in Shifting Cultivation Regions – The Experience with Cardamom in Laos

Farmers are often blamed for destroying the tropical forest, especially in Laos. Converting shifting cultivation into cash crop based agriculture is frequently presented as the solution for merging forest protection and poverty alleviation, but many attempts have ended in failure. A rural development project has attempted to introduce medicinal cardamom (Amomum villosum) cultivation in the notably remote region of Phongsaly (northern Laos), for export to China. With nearly 300 ha planted, the crop now involves about 75% of the farmers in the region. Farmers fitted cardamom into their farming system, to suit their needs for sustainability with a crop compatible with existing practices. Results indicate that introducing a cash crop into a shifting cultivation region is possible if a greater attention is paid to: (i) appraise how the new crop fits into the farming systems; (ii) prioritise economic issues over agronomic matters, in particular identify markets, traders or commercial risks.     

Shifting cultivation systems practised in Bhutan

In the highlands of Bhutan shifting cultivation remains an important land use practice, covering an area of approximately 200,000 ha. Two systems, bush fallow and grass fallow, are described and discussed. The traditional methods used in the two systems are well adapted to available resources. The systems differ in fallow vegetation, altitude range, major crops, fallow period, farming tools, clearing method, labour inputs, and erosion risks. Soils used for the grass fallow system are low in P and N. Major limitations for the bush fallow system are weed competition and the steep terrain. Returns from labour wereapproximately 10.6 and 4.2 kg grain per day for the bush fallow and the grass fallow system, respectively. Access to market through a recently built road system provides some cultivators with lucrative alternatives in the form of timber, livestock and potato production. Alternative options are more limited in the bush fallow system.This work was supported by the Department of Agriculture, Royal Government of Bhutan and the Swiss Association for Technical Assistance     

Shifting cultivation in steeply sloped regions: a review of management options and research priorities for Mizoram state,Northeast India

Shifting cultivation is a common agricultural practice that is the basis of subsistence for many rural populations throughout the Tropics. The recent strong trend towards shorter fallow periods has led to widespread concern about declines in soil fertility, crop yields, and food security. Unlike most research on this problem, we focus here on steeply sloped regions such as Mizoram state in northeast India where most land is at an incline of >33°, and the potential for relatively large soil erosional losses may necessitate distinctive solutions. Our goal is to review the relevant literature so as to optimize the direction and quality of future science research on shifting cultivation in Mizoram. Our analysis suggests that the most promising options for improving shifting cultivation are nutrient and water supplementation, optimising crop choice, extending the site use period, enhancing the fallow recovery rate, and controlling the burns and their environmental impacts. Promising alternatives for replacing shifting cultivation include inter-row cropping between contour hedgerows of nitrogen-fixing shrubs, slope terracing, agroforestry with anti-erosional plants, and bamboo forest harvesting. In addition, we identify the principal research questions that should be addressed before each of these options can be evaluated and recommended as part of land use planning initiatives. Overall, we conclude that intelligent and careful use of commercial fertilizer in combination with organic matter additions is likely to be an important feature of many of the solutions to the problem of shortening fallow periods in shifting cultivation on steep slopes.     

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.     

Effect of alley cropping on soil aggregate stability of a tropical Alfisol

The beneficial effect of organic matter on soil aggregate stability is well documented. Alley cropping has been suggested as a possible alternative to maintain soil organic matter content in cropping systems without fallowing the land. The objective of this study was to asses the effect of alley cropping on dry and wet soil aggregate stability on land degraded by shifting cultivation. The aggregate size distribution by dry sieving, aggregate stability by wet sieving, soil organic Carbon content and soil bulk density were measured following two and three years of alley cropping with Gliricedia (Gliricidia sepium) and Pigeon pea (Cajanas cajan) in a tropical Rhodustalf. Alley cropping increased the mean aggregate diameter and water stability of soil aggregates. The mean aggregate diameter obtained from dry sieving increased from 1.3 mm of the control to 2.68 and 3.11 mm after three years in Pigeon pea and Gliricidia alley cropped plots, respectively. This is an indication of resistance to wind erosion in alley cropped plots. The wet aggregate stability which shows the resistance to erosion by water also increased in alley cropped plots. These increases were significant after three years of hedge row establishment. The increase in soil organic C in alley cropped plots contributed to the higher dry and wet aggregate stability, and decreased soil bulk density. The improvement was higher in plots alley cropped with Gliricidia than Pigeon pea. This study shows the importance of ally cropping in increasing aggregate stability of degraded sandy soils which in return reduce erosion by wind and water.     

A diagnostic survey of shifting cultivation in northern Laos: targeting research to improve sustainability and productivity

About 25% of Laos' four million people practise shifting cultivation (mainly of rice) on a third of the country's cropped area. Official policy is to eliminate shifting cultivation by the year 2000. Diagnostic surveys of shifting cultivation were conducted in Luang Prabang and Oudomsay Provinces in northern Laos to understand the practice from a farmer's perspective, to observe fields, and to identify and give priority to problems and research to address problems. Weeds, low and possibly declining soil fertility, intensification of the cropping cycle, rats (plus birds, wild pigs), and insects lowered rice yields or reduced system sustainability. The forest ecosystem has been degraded by logging, burning, and rice monocropping; and potentials for environmental rehabilitation through natural succession are minimal. Farmers cannot adopt high labor and cash cost innovations; and improved fallow is needed as an intermediate step prior to crop diversification, adoption of agroforestry technologies, and sedentary agriculture.     

Smallholder Cacao (Theobroma cacao Linn.) cultivation in agroforestry systems of West and Central Africa: challenges and opportunities

The cultural features, management practice, environmental sustainability, and economic profitability of smallholder cacao (Theobroma cacao)production in West and Central Africa are reviewed. The aim is tohighlight factors affecting the cacao production and marketing sectorand to propose appropriate strategies to ensure sustainable and profitable cacao production in the region. The cacao cultivation system causes minimum damage to soil resources. In terms of carbon sequestration and below- and above-ground bio-diversity, the cacao agroforest is superior to the alternative food crop production land use. The food crop production system is based on the practice of slash-and-burn farming, which, due to population pressure and reduced fallow cycle, is no longer sustainable. Economic profitability analysis of this system in Cameroon showed that, at current prices, even with no value assigned to the tree species, the sector could still be profitable. Based on the current review and our knowledge of West and Central Africa, there is an urgent need to: (a) rationalize and optimize arrangement of the various components in cacao agroforest, (b) domesticate high value and shade tolerant indigenous species such as Gnetum africanum and integrate into the system in order to enhance the system's diversity and profitability, (c) develop shade-tolerant and disease-resistant cacao varieties, (d) integrate small-stock production into the system, and (e) develop an enabling policy environment addressing cacao marketing, plant protection, land tenure and transformation of non-cacao primary products from the cacao agroforests. This revised version was published online in June 2006 with corrections to the Cover Date.     

A shifting cultivation land use system under population pressure in Zambia

The status of chitemene shifting cultivation, in northern Zambia was investigated and reviewed. This paper presents results concerning (a) changes in soil nutrients under chitemene shifting cultivation, (b) the relationship between population density and deforestation and (c) how the chitemene shifting cultivation system has survived under conditions of overpopulation relative to the critical population density.In the chitemene shifting cultivation system crops are grown in a small ash garden made by burning a pile of wood cleared from a larger area. The burning increased soil NH₃–N content by 40–50%, with a further increase of 15% after 262 mm of rainfall. In contrast, the soil in unburnt plots lost up to 30% NH₃–N. The content of other major nutrients, such as, P,K, Ca, Mg, and Na also increased in the top soil immediately after burning. The increase in soil NH₃–N after burning is attributed to the reduction in microbacterial activity. These soil nutrient changes appear essential in the production of finger millet.However, the growing rural population in the chitemene shifting cultivation region of northern Zambia has caused deforestation which has resulted in the reduction of (a) the length of the fallow period from 25 years to 12 years, (b) the per person woodland requirement of m 1.1 ha to 0.53 ha and (c) the frequency of clearing new chitemene gardens from yearly to once in two years. These responses to diminishing wood resources have artificially increased the population carrying capacity from 2.4 to 18.7 persons per km². This has enabled the survival of the chitemene shifting cultivation land use system in northern Zambia.     

海南岛尖峰岭半落叶季雨林生态效应的研究Ⅳ—游耕农业的地力分析

本文根据在海南岛尖峰岭林区半落叶季雨林—褐色砖红壤上所进行的游耕农业生态后果的实验研究,论证了热带森林土壤资源退化的四个方面:凋落物层烬失,使土壤养分补给源和水文功能减弱;水土流失严重;水分的输导、涵贮能力降低;上壤理化性状劣变,肥力下降。文章提出了废除游耕制,建立以木本植物为主的林—农制;合理规划和经营热带林;停止炼山全垦法,推行生态造林技术等项建议,以培育和保持地力,保护热带森林土壤资源。     

Chromolaena odorata in slash-and-burn rice systems of Northern Laos

Chromolaena odorata, introduced to Laos in the 1930s, has become the most abundant weed and fallow species in slash-and-burn fields over a wide range of land use systems, elevation, and pH ranges. Regeneration from roots, high seed production and easy dispersal allow for the rapid colonization of fields in the initial fallow period. At rice harvest, after a 1-year and a 2-year fallow, the total aboverground biomass in monitoring plots was 1.4, 10, and 15.4 t ha^–1, with 16, 48, and 29% contribution byC. odorata, respectively. With progressing fallow periodC. odorata is gradually replaced by tree and bamboo species. Slash-and-burn farmers preferredC. odorata over other fallow species common in their fields.Chromolaena odorata is an excellent fallow species considering its fast expansion after crop harvest, high biomass production, weed suppression, and fast decomposition rate. Some of these properties may, however, become a serious disadvantage when farmers gradually change to land use systems that integrate grazed fallow, crop rotation, and/or fruit and timber plantations.