The Sustainable Agriculture and Natural Resource Management Collaborative Research Support Program (SANREM CRSP), funded by U.S. AID, aims to develop principles and methodologies for achievement of sustainable ecosystem management at the watershed and landscape scale. In contrast to much of the earlier literature in environmental, agricultural, and ecological science which portrays humans as the despoilers of ecosystems, the SANREM approach acknowledges the role of people as integral actors who must be directly engaged in sustainable development if it is to be successful. The SANREM approach, therefore, uses an interdisciplinary, farmer-participatory research, training and information exchange strategy to bridge between scientific knowledge and local expertise in the resolution of problems. A landscape ecology approach is used to describe and understand the complex internal, external, and interactive processes within and between the individual ecosystems of a toposequence transecting two or more agroecological zones. Coupled with the landscape notion is that of “lifescape”, or the human dimension, which includes economic, cultural and social aspects in interaction with the physical and biological dimensions of ecosystems. Interventions appropriate to the local farm community members are designed and evaluated in concert with the ultimate users who are involved in all steps of the research process. The approach includes emphasis on collaboration between biological and social scientists and development practitioners in the U.S. and host countries. It also strives for interinstitutional collaboration that involves private and public institutions from each country as well as the U.S. The SANREM project is considered one of the first of its kind, a pioneering effort to solve complex natural resource and sustainable agriculture problems involving a wide range of stakeholders who may have conflicting interests among themselves. These stakeholders include local communities, international research and development organizations, U.S. universities, host country universities and government agencies, local government and nongovernment organizations (NGOs). Also, there is a need to address experimentally a hierarchical range of spatial and temporal scales across a landscape. In attempting to meet these challenges, we have many successes, many failures and many lessons learned. This chapter outlines the experiences of SANREM at the core sites in the Philippines, Burkina Faso, and Ecuador, and presents critical lessons learned in implementing a large landscape-scale research and education program
Tag: hedgerow plants
Biomass production and root distribution of eight trees and their potential for hedgerow intercropping on an ultisol in Southern Sumatra
The results are reported of 2 experiments with exotic and local tree species, in order to assess their suitability for alley cropping on an acid soil, and as part of a nitrogen management project carried out in Lampung. The first experiment was an alley cropping trial established in 1986 and 1987 on a site cleared of secondary forest in 1986. The hedgerow species tested were Calliandra calothyrsus, Gliricidia sepium, Leucaena leucocephala, Peltophorum pterocarpa [P. pterocarpum] and Erythrina orientalis, with Mucuna pruriens var. utilis used initially as a leguminous cover crop. Tree spacing was 4 m between rows and 0.5 m within rows. Regular pruning and intercropping with food crops started in 1988. The trees were pruned every 4 months to 1 m height for 3 consecutive growing seasons (forming a hedge 40 cm wide), and thereafter the regime was adapted according to the crop. Dry weight production and N yield of prunings (which were added to the soil) was recorded, and differences in canopy shape and root distribution between the species (and their potential effects on crops) discussed. C. calothyrsus produced the most biomass, and E. orientalis the least. The second experiment examined the effect of stem pruning height and root pruning on 6 leguminous tree species (Calliandra calothyrsus, Cassia siamea, E. orientalis, Peltophorum pterocarpum, G. sepium and Albizia falcataria) and one non-legume (Peronema canescens). The trees were planted in February 1988 on a plot recently cleared of forest vegetation in rows 2 m apart, and with an inter-row spacing of 0.5 m. Root pruning was done in December 1988 (and annually thereafter) by digging a 20-cm deep trench 50 cm from the tree row. Pruning heights of 50, 75 and 100 cm were tested at 4-8 month intervals. Observations were recorded on biomass production at pruning, canopy shape, specific leaf area, light interception at ground level and root distribution, dry weight, density and nodulation. Lower pruning heights led to less biomass production and an increase in the number of branch roots originating from the stem base. A. falcataria and Peronema canescens did not tolerate regular pruning well. Consistent effects were not demonstrated of root pruning on biomass production in relation to stem pruning. Overall, the results demonstrate that the most suitable species for alley cropping on this acid soil is the relatively deep rooted Peltophorum pterocarpum; otherwise alternating hedgerows of P. pterocarpum and G. sepium are suggested as suitable. P. pterocarpum formed the densest canopy in a small hedge volume when pruned in a 3-month-cycle. Calliandra calothyrsus produced more biomass and supplied more nitrogen than any other species but would need more regular pruning to avoid shading intercrops; this could be compensated for by growing the trees at greater inter-row distances. The other species tested were all less suitable for alley cropping.
Building the smallholder into successful natural resource management at the watershed scale
This chapter explores the issues surrounding successful conservation farming as a process defined by spontaneous adoption. It assesses the components of a low-labour hedgerow system of pruned leguminous trees (Chromolaena odorata, Paspalum, or Digitaria) as an approach to a technical solution, and addresses the issue of how to disseminate information about a conservation technology cost-effectively at a sustainable rate. Rapid adoption of a low-labour, zero-cash-cost conservation practice based on natural vegetative strips in Claveria, northern Mindanao, the Philippines that led to examination of each component of the process of establishing and maintaining low-labour hedgerow practices was observed. A Contour Hedgerow Extension Team (CHET), established to respond to farmer interest, initially worked with individual farmers who requested their assistance. This evolved into supporting a peoples’ conservation organization (Land Care Association) that took on the main responsibility for technology dissemination. Local government became involved in supporting the effort financially, with active involvement of the village leaders (a process led by local government). It is planned to scale-up the effort to the watershed and regional levels, and evaluate whether it is practical in the context of agroecological domains.
Adoption of agroforestry technology: The case of live hedges in the central plateau of Burkina Faso
Off-season farming activities contribute significantly to household income in the central plateau of Burkina Faso. Cattle and small ruminants are also important. The lack of rules regulating animal browsing during the dry season, unlike during the rainy season, has created competition for available land resources among the components of the land use sub-system. This study describes traditional practices utilized to protect home gardens from animals, how these practices have evolved over time and examines factors that affect the adoption of live hedges. Informal and formal surveys were undertaken in the study area in 1993. Five types of traditional method for protecting gardens from animals were identified. A logit model integrating technology profitability as an explanatory variable was used to study farmers’ decision processes to live hedges adoption. The results indicate that water availability and the profitability of the technology itself enhance the probability of adopting live hedges. The results provide an insight into conditions that should be taken into consideration when targeting farmers for this agroforestry technology.
Between scattered extraction and specialized production : which alternatives for the development of non-timber forest resources?
Management systems for NTFPs are far from being homogenous. They globally range from scattered collection in natural forests foe occasional consumption to intensive specialized production for international markets, going through various types of “integrated management” and “occasional cultivation” or ” per-domestication”. These various systems have obviously different features in terms of either ecological, economic or social sustainability, of short term or long term productivity, or of cultural validity. Among others, they may have totally diverging impacts on either forest ecosystems and biodiversity conservation, on forest populations development and welfare, or even on the respect of indigenous people rights. This paper will first attempt to give a dynamic overview of this diversity of current management practices for NTFPs, highlighting past and present evolutionary trends and insisting on those currently less investigated models that are intermediary between “extraction from natural stocks” and “true domestication for cultivation”, with a special focus on the Southeast region. Starting from these current situations, it will elaborate on the available “existing models” for NTFPs management, giving attention to matters such as scale and scope of management, levels of inputs and knowledge, economic and social logics, institutional and social bases. It will launch important bases for a comparative assessment of the global sustainability of these models, examining ecological, economic, cultural and social efficiency and gaps. It will finaly try to derive “alternative models” for future scenarios of forest management, giving a special attention to unexplored ways for demestication of forest resources.
Assessing the adoption potential of hedgerow intercropping for improving soil fertility, western Kenya
The biophysical and socioeconomic performance of hedgerow intercropping for soil fertility improvement was assessed in a farmer-participatory trial in western Kenya over 3 years. Farmers successfully established dense hedgerows but planting and pruning considerably increased labour use during the busiest period of the year. Women did not generally prune the hedges. The yields of hedgerow prunings of Leucaena leucocephala and Calliandra calothyrsus (1–4 t ha1 year1, n = 24) were low compared to potentials in the region (4–8 t ha1). The hedgerows had no effect on grain yield over five seasons. But they reduced slopes from 7.2 to 4.5% within alleys (P < 0.01) and thus were likely to have decreased soil erosion. The average extra maize yield required each year, beginning in the second year, to cover the added cost of hedgerow intercropping was 10.5% (SD = 5.5%) when based on returns to land, and 17.5% (SD = 6.5) based on returns to labour. Although about half the farmers claimed that hedges improved crop yields, after 3 years of experimentation, only about a fifth planted additional hedges and only14% did so to improve soil fertility. It thus appears that the potential for its adoption as a soil fertility practice in this area is low. Hedgerow intercropping appears to have greater adoption potential if its aim is to provide feed for an intensive dairy operation or for curbing soil erosion. Control plots were of little use as farmers were more interested in contrasting test-plot yields with past yields than comparing the test and control plots. Different types of trials may be required to obtain reliable biophysical data on yield response and socioeconomic data on farmer assessment of complex agroforestry technologies.
Soil property changes in contour hedgerow systems on sloping land in the Philippines
The impact of contour hedgerow systems on soil sustainability under acidic conditions has been widely criticized. A study was undertaken to determine the effects of management and hedgerow species on soil properties. Cassia spectabilis (a non-N-fixing tree legume), Gliricidia sepium (an N-fixing tree legume), Pennisetum purpureum (a forage grass), and Stylosanthes guyanensis (a forage legume) contour barriers were compared with an open field (non-hedgerow treatment) over 1 cowpea and 2 rice seasons. Three types of management viz.: prunings applied + N0P0K0, prunings applied + N50P20K20 and prunings removed + N50P20K20 were used as subplot treatments. The soils were strongly acidic (pH 4.5) and classified as clay Orthoxic Palehumult. Cassia performed better than the other species in terms of pruning biomass, N and P contributions over a period of 20 months. There was a combined positive effect of pruning biomass and fertilizers on rice and cowpea yields in Pennisetum and Gliricidia systems, while a tendency towards a positive effect of pruning biomass on rice was found in the Cassia system. The pruning biomass and/or fertilizer application did not significantly influence the top soil organic C, N and available P in the hedgerow systems. Soil bulk density was significantly reduced by the application of Cassia prunings after 12 months. Organic C, N and P dynamics indicated that in situ pruning biomass was not sufficient to maintain their level in the soil. But the cassia systems with prunings applied + N50P20K20 experienced the lowest degradation in soil organic C (2.1 t ha1) followed by the Gliricidia systems (4.1 t ha1). The overall results imply that the application of pruning and inorganic fertilizer is imperative to conserve soil resources, and non- N-fixing tree species can exert a significant advantage in biomass and thereby in soil N-recycling under acidic soil.
Appropriate spacing for natural vegetative filter strips in upland conservation farming systems
Natural vegetative filter strips (NVS) are attractive contour hedgerow system because they are simple to establish and maintain, control erosion effectively, and compete less with associated annual crops than other alternatives. The recommended practice has been to space the hedgerows every 1 meter drop in elevation. This results in close hedgerow spacing(3-6m apart) which removes considerable area from crop production. A collaborative study between the International Centre for Research in Agroforestry (ICRAF) and Misamis Orientak State College of Agriculture and Technology (MOSCAT) to determine the effect of NVS density om crop production and soil loss.