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The European Commission recently set a target of increasing the area of organic agriculture to 25% by 2030. To achieve this, it is imperative to understand current nutrient use patterns and identify sustainable nutrient supply opportunities. To that end, this study assessed the sustainability of the current nutrient origin and supply of 71 arable organic farms in 8 European regions. Deficient nutrient supply was found on 24%, 66%, and 56% of farms for nitrogen, phosphorus, and potassium, respectively. On average, we show a moderate surplus for nitrogen (28 kg ha−1), while phosphorus and potassium balances were close to zero (− 1 and 2 kg ha−1, respectively). Large variation between countries and farm types shows a divide between more intensive systems relying on external inputs, and less intensive systems facing nutrient deficits and lower outputs. We show, for the first time, the extent of current use of external input types, where conventional manures supplied 17–26% of external nutrients and inputs from non-agricultural origin supplied 31–41%. A large proportion of nutrient sources within the last group are materials derived from urban wastes. The sustainable expansion of the organic sector will require increased use of locally available recycled fertilizers from urban wastes, and acceptance of such sources by organic farmers is shown to be high, provided they are considered safe.

The European Commission recently set a target of increasing the area of organic agriculture to 25% by 2030. To achieve this, it is imperative to understand current nutrient use patterns and identify sustainable nutrient supply opportunities. To that end, this study assessed the sustainability of the current nutrient origin and supply of 71 arable organic farms in 8 European regions. Defcient nutrient supply was found on 24%, 66%, and 56% of farms for nitrogen, phosphorus, and potassium, respectively. On average, we show a moderate surplus for nitrogen (28 kg ha−1), while phosphorus and potassium balances were close to zero (−1 and 2 kg ha−1, respectively). Large variation between countries and farm types shows a divide between more intensive systems relying on external inputs, and less intensive systems facing nutrient defcits and lower outputs. We show, for the frst time, the extent of current use of external input types, where conventional manures supplied 17–26% of external nutrients and inputs from non-agricultural origin supplied 31–41%. A large proportion of nutrient sources within the last group are materials derived from urban wastes. The sustainable expansion of the organic sector will require increased use of locally available recycled fertilizers from urban wastes, and acceptance of such sources by organic farmers is shown to be high, provided they are considered safe.

The increasing resource and ecological challenges in agriculture necessitate agricultural intensification and resource optimization. This study focuses on agroecological intensification using organic practices. It compares the production efficiency of the organic and non-organic smallholder kale production systems in Kenya. Using survey data collected from Kenya, the study estimated production (cost and revenue) efficiency of the kale production system by conducting data envelopment and stochastic frontier analysis and subjected the efficiency measures to propensity score matching analysis. The results show no significant difference in cost efficiency between organic and non-organic kale producers. However, revenue efficiency and income per unit production cost are lower among organic than non-organic kale producers. The results also show that the efficiency and productivity of the organic smallholder kale production system are limited by a lack of inputs (especially manure) but not labor. This implies that improving the efficiency of the smallholder organic kale production system requires more use of organic manure as well as research and training on organic pesticides. The finding concurs with literature that reports organic input problems and lower productivity in organic than non-organic production systems in developing countries and Kenya, especially in vegetables. It also shows that the organic production system is more labor-intensive than the non-organic system.

Limited nutrient availability is one of the major challenges in organic farming. Little is known about nutrient budgets of organic farms, the underlying factors or effects on soil fertility. We therefore assessed farm gate nutrient budgets for nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg) and sulfur (S) of 20 organic farms in Germany and analyzed their soil nutri-ent status. In average, the budgets showed a surplus of N (19 kg ha−1), K (5 kg ha−1), S (12 kg ha−1), and Mg (7 kg ha−1), and a deficit of P (−3 kg ha−1). There was, however, high variability between farms (e.g. standard deviation up to ± 36 kg N ha−1), which was mainly explained by different degrees of reliance on biological N fixation (BNF) as N source. When farms obtained more than 60% of their N input through BNF, they had deficits of P (mean −8 kg P ha−1) and K (mean −18 kg K ha−1). Nutrient status of most soils was within the ad-vised corridor, but for P, K and Mg, 10–15% of fields were lower and 45–63% were higher than advised. Extractable soil nutrient contents did not correlate with the nutrient budgets, inputs or outputs. Only extractable soil P increased with increasing P inputs and outputs. Fur-thermore, a decrease in extractable soil P was detected with a prolonged history of organic farming, indicating a risk of soil P mining in organic farming systems. In conclusion, the study revealed nutrient imbalances in organic farming and pointed to P and K scarcity as a major challenge for organic farms with high reliance on BNF in the long term.

Organic agriculture uses contracts and networks to overcome its asset‐specificity problems and to ensure compliance with its standards and norms, including environmental conservation. This study analyzed the effects of certified‐organic production on supplier failures and the potential income effects of these failures on vegetable and macadamia producers in Kenya. Using survey data and propensity score matching, the study found that organic macadamia production reduces delivery failures because its asset specificity necessitates a dedicated transport system. It also found that organic vegetable production reduces quality failures because organic consumers are often less concerned about the physical quality of organic produce. However, despite these advantages, cases of supplier failures are still rampant among both organic and nonorganic producers of macadamia and vegetables. The potential income effects of these supplier failures, especially quantity and delivery failures in macadamia, raise concerns. These problems necessitate policy interventions, especially with respect to establishing and strengthening producer organizations, which are often very instrumental in overcoming quality, quantity, and delivery failures.

We test the hypothesis that agroforestry improves livelihoods and mitigates climate change in smallholder farming systems simultaneously. Data were collected using household surveys and standard biomass assessment approaches using locally relevant allometric equations. Summary statistics and regression analyses reveal linkages between on-farm carbon stocks and farm- and household characteristics. With an average of 4.07 ± 0.68 Mg C ha −1 and Shannon diversity index of 3.06, farm carbon stocks were significantly associated with farm size (r = 0.453, p < 0.05), tree density (r = − 0.58, p = 0.05) and the average size of trees on farm (r = − 0.42, p = 0.05), but not by Shannon diversity index (r = 0.36, p = 0.080), species richness (r = − 0.044, p = 0.833) or the number of land use categories (r = − 0.192, p = 0.356). Timber was considered the most important use of on-farm trees before firewood and construction material. The results suggest that gaining self-sufficiency in firewood is the most important benefit with on-farm carbon accumulation. The focus on exotic species for timber production presents a considerable trade-off between livelihood options and environmental goals. Heterogeneity in local environmental conditions over very short distances, less than 12 km, significantly determine livelihood strategies and on-farm carbon stocks. These results ostensibly contradict that carbon storage in smallholder farms is determined by diversity of tree species, suggest that livelihood strategy can equally drive carbon storage and demonstrate the diversity of livelihood and environmental benefits derived from trees on farms.

Organic farming is under constant pressure to reinvent itself by adopting new technologies. This article examines the role of precaution in organic farmers’ assessments of new technologies, and asks how their assessments draw on different types of knowledge. The article further explores how knowledge type compares to the role of knowledge and precaution expressed in the principles of organic farming as defined by the organic movement organisation, IFOAM. Results from a study of the introduction of sewage sludge as an alternative source of nutrients in organic agriculture are presented. Empirically, this case-study builds on the analysis of five focus groups made up of Danish organic farmers. While some farmers called for precaution, supporting this with claims about lacking knowledge, others trusted the authorities and accepted sewage sludge provided it was officially approved for organic use. Our analysis suggests that when assessing new technologies Danish organic farmers rely on scientific knowledge and do not automatically draw on the experiential knowledge they possess and employ in other contexts. It is concluded that if IFOAM wishes include farmers’ experiential knowledge as a basis for decisions about precaution, there is a need to develop instruments making it possible to tap into this knowledge.

Efforts have been made in recent years to improve knowledge about soil greenhouse gas (GHG) fluxes from sub-Saharan Africa. However, data on soil GHG emissions from smallholder coffee-dairy systems have not hitherto been measured experimentally. This study aimed to quantify soil GHG emissions at different spatial and temporal scales in smallholder coffee-dairy farms in Murang'a County, Central Kenya. GHG measurements were carried out for one year, comprising two cropping seasons, using vented static chambers and gas chromatography. Sixty rectangular frames were installed on two farms comprising the three main cropping systems found in the area: 1) coffee (Coffea arabica L.); 2) Napier grass (Pennisetum purpureum); and 3) maize intercropped with beans (Zea mays and Phaseolus vulgaris). Within these fields, chambers were allocated on fertilised and unfertilised locations to capture spatial variability. Cumulative annual fluxes in coffee plots ranged from 1 to 1.9 kg N2O-N ha− 1, 6.5 to 7.6 Mg CO2-C ha− 1 and − 3.4 to − 2.2 kg CH4 -C ha− 1, with 66% to 94% of annual GHG fluxes occurring during rainy seasons. Across the farm plots, coffee received most of the N inputs and had 56% to 89% higher emissions of N2O than Napier grass, maize and beans. Within farm plots, two to six times higher emissions were found in fertilised hotspots – around the perimeter of coffee trees or within planted maize rows – than in unfertilised locations between trees, rows and planting holes. Background and induced soil N2O emissions from fertiliser and manure applications in the three cropping systems were lower than hypothesized from previous studies and empirical models. This study supplements methods and underlying data for the quantification of GHG emissions at multiple spatial and temporal scales in tropical, smallholder farming systems. Advances towards overcoming the dearth of data wil

Organic farming is under constant pressure to reinvent itself by adopting new technologies. This article examines the role of precaution in organic farmers' assessments of new technologies, and asks how their assessments draw on different types of knowledge. The article further explores how knowledge type compares to the role of knowledge and precaution expressed in the principles of organic farming as defined by the organic movement organisation, IFOAM. Results from a study of the introduction of sewage sludge as an alternative source of nutrients in organic agriculture are presented. Empirically, this case-study builds on the analysis of five focus groups made up of Danish organic farmers. While some farmers called for precaution, supporting this with claims about lacking knowledge, others trusted the authorities and accepted sewage sludge provided it was officially approved for organic use. Our analysis suggests that when assessing new technologies Danish organic farmers rely on scientific knowledge and do not automatically draw on the experiential knowledge they possess and employ in other contexts. It is concluded that if IFOAM wishes include farmers' experiential knowledge as a basis for decisions about precaution, there is a need to develop instruments making it possible to tap into this knowledge., Organic farming is under constant pressure to reinvent itself by adopting new technologies. This article examines the role of precaution in organic farmers' assessments of new technologies, and asks how their assessments draw on different types of knowledge. The article further explores how knowledge type compares to the role of knowledge and precaution expressed in the principles of organic farming as defined by the organic movement organisation, IFOAM. Results from a study of the introduction of sewage sludge as an alternative source of nutrients in organic agriculture are presented. Empirically, this case-study builds on the analysis of five focus groups made up of Danish organic farmers. While some farmers called for precaution, supporting this with claims about lacking knowledge, others trusted the authorities and accepted sewage sludge provided it was officially approved for organic use. Our analysis suggests that when assessing new technologies Danish organic farmers rely on scientific knowledge and do not automatically draw on the experiential knowledge they possess and employ in other contexts. It is concluded that if IFOAM wishes include farmers' experiential knowledge as a basis for decisions about precaution, there is a need to develop instruments making it possible to tap into this knowledge.

Agriculture is one of the major sources of nitrous oxide (N2O), a potent greenhouse gas (GHG) whose atmospheric concentrations are estimated to increase with efforts to increase food production through increasing nitrogen (N) inputs. The objective of this study was to quantify N2O emissions from maize (Zea mays L.) and winter wheat (Triticum aestivum L.) fields amended with inorganic, organic N and a combination of both sources (integrated management), in tropical (Zimbabwe) and temperate (China) climatic conditions. In Zimbabwe N2O emissions were measured from maize plots, while in China emissions were measured from maize and winter wheat plots. In Zimbabwe the treatments were; (i) Control, (ii) 60 kg N ha−1 ammonium nitrate (NH4NO3), (iii) 120 kg N ha−1 NH4NO3, (iv) 60 kg ha−1 cattle (Bos primigenius) manure-N, plus 60 kg N ha−1 NH4NO3, (v) 60 kg N ha−1 cattle manure-N, and (vi) 120 kg N ha−1 cattle manure-N. In China, treatments were; (i) Control, (ii) 300 kg N ha−1 Urea, (iii) 92 kg N ha−1 Urea plus 65 kg ha−1 chicken (Gallus domesticus) manure-N, (iv) 100 kg N ha−1 Urea and (v) 100 kg N ha−1 control release Urea. Our results showed that under both temperate and tropical conditions, integrated nutrient management resulted in lower N2O emissions compared to inorganic fertilizers which had higher total and yield-scale N2O emissions. We conclude that by combining organic and inorganic N sources, smallholder farmers in both China and Zimbabwe, and other countries with similar climatic conditions, can mitigate agricultural emissions without compromising productivity.

Demand for tools to rapidly assess greenhouse gas impacts from policy and technological change in the agricultural sector has catalyzed the development of 'GHG calculators'- simple accounting approaches that use a mix of emission factors and empirical models to calculate GHG emissions with minimal input data. GHG calculators, however, rely on models calibrated from measurements conducted overwhelmingly under temperate, developed country conditions. Here we show that GHG calculators may poorly estimate emissions in tropical developing countries by comparing calculator predictions against measurements from Africa, Asia, and Latin America. Estimates based on GHG calculators were greater than measurements in 70% of the cases, exceeding twice the measured flux nearly half the time. For 41% of the comparisons, calculators incorrectly predicted whether emissions would increase or decrease with a change in management. These results raise concerns about applying GHG calculators to tropical farming systems and emphasize the need to broaden the scope of the underlying data.

Black wattle (Acacia mearnsii, De Wild.) is a fast growing tree species introduced into South Africa in the nineteenth century for commercial purposes. While being an important source of timber and firewood for local communities, black wattle is an aggressive invasive species and has pervasive adverse environmental impacts in South Africa. Little is known about the effects of black wattle encroachment on soil carbon, therefore the aim of this study was to investigate the impact of black wattle encroachment of natural grassland on soil carbon stocks and dynamics. Focussing on two sites in the Eastern Cape, South Africa, the study analysed carbon stocks in soil and litter on a chronosequence of black wattle stands of varying ages (up to >50 years) and compared these with adjacent native grassland. The study found that woody encroachment of grassland at one site had an insignificant effect on soil and litter carbon stocks. The second site showed a clear decline in combined soil and litter carbon stocks following wattle encroachment. The lowest stock was in the oldest wattle stand, meaning that carbon stocks are still declining after 50 years of encroachment. The results from the two sites demonstrate the importance of considering changes in soil carbon when evaluating ecosystem effects of invasive species., Black wattle (Acacia mearnsii, De Wild.) is a fast growing tree species introduced into South Africa in the nineteenth century for commercial purposes. While being an important source of timber and firewood for local communities, black wattle is an aggressive invasive species and has pervasive adverse environmental impacts in South Africa. Little is known about the effects of black wattle encroachment on soil carbon, therefore the aim of this study was to investigate the impact of black wattle encroachment of natural grassland on soil carbon stocks and dynamics. Focussing on two sites in the Eastern Cape, South Africa, the study analysed carbon stocks in soil and litter on a chronosequence of black wattle stands of varying ages (up to >50 years) and compared these with adjacent native grassland. The study found that woody encroachment of grassland at one site had an insignificant effect on soil and litter carbon stocks. The second site showed a clear decline in combined soil and litter carbon stocks following wattle encroachment. The lowest stock was in the oldest wattle stand, meaning that carbon stocks are still declining after 50 years of encroachment. The results from the two sites demonstrate the importance of considering changes in soil carbon when evaluating ecosystem effects of invasive species.

To avoid the risks of conventionalisation and becoming a modified version of conventional farming, organic farming is under a continuous pressure to reinvent itself by adopting new technologies. This article examines the role of precaution in organic farmers’ assessment of potential new technologies, and how farmer’s assessment draws on different types of knowledge. The article further explores how knowledge type compares to the role of knowledge and precaution set forth in the principles of organic farming by the organic movement (IFOAM). Results from a case study of the introduction of sewage sludge as an alternative – and controversial - source of nutrients in organic agriculture are presented. Empirically, this case study builds on the analysis of five focus groups with Danish organic farmers. While some farmers called for precaution often backed by an observation of lacking knowledge, others trusted the authorities and accepted sewage sludge, provided it is approved for organic use by the authorities. Our analysis suggests that there is a mismatch between the kind of knowledge used by organic farmers when assessing the new technology, drawing heavily on scientific knowledge, and IFOAMs principles, also hailing experiential knowledge.

Soil organic carbon (SOC) is broadly recognised as an important parameter affecting soil quality, and can therefore contribute to improving a number of soil properties that influence crop yield. Previous research generally indicates that soil organic carbon has positive effects on crop yields, but in many studies it is difficult to separate the effect of nutrients from the effect of SOC in itself. The aim of this study was to analyze whether the SOC content, in itself, has a significant effect on potential yields of commonly grown cereals across a wider range of soil types in Denmark. The study draws on historical data sets from the Danish national field trials consisting of 560 winter wheat (Triticum aestivum L.) trials and 309 spring barley (Hordeum vulgare L.) trials conducted over the past 20 and 17 years, respectively. We hypothesised that for these two crops, the potential grain yield, the yield with no fertiliser N application and the N use efficiency would be positively affected by SOC level. A statistical model was developed to explore relationships between SOC and potential yield, yields at zero N application and N use efficiency (NUE). The model included a variety of variables and aimed to elucidate the sole effect of SOC by controlling for potential confounding variables. No significant effect of SOC on potential winter wheat was found, whilst for spring barley, only for the course sandy loam soil type was a borderline significantly positive effect of SOC on potential yields found. The relationship between unfertilized plot yields and SOC was positive for winter wheat, although not significant, whilst for spring barley a significant positive effect of SOC was found only for the coarse sandy soil type, and a borderline significant positive effect of SOC was found for the coarse sandy loam soil type. A significant negative relationship was found between SOC and NUE for both winter wheat and spring barley. Based on the large dataset analyzed, we cautiously

Agriculture is one of the major sources of nitrous oxide (N2O), a potent greenhouse gas (GHG) whose atmospheric concentrations are estimated to increase with efforts to increase food production through increasing nitrogen (N) inputs. The objective of this study was to quantify N2O emissions from maize (Zea mays L.) and winter wheat (Triticum aestivum L.) fields amended with inorganic, organic N and a combination of both sources (integrated management), in tropical (Zimbabwe) and temperate (China) climatic conditions. In Zimbabwe N2O emissions were measured from maize plots, while in China emissions were measured from maize and winter wheat plots. In Zimbabwe the treatments were; (i) Control, (ii) 60 kg N ha-1 ammonium nitrate (NH4NO3), (iii) 120 kg N ha-1 NH4NO3, (iv) 60 kg ha-1 cattle (Bos primigenius) manure-N, plus 60 kg N ha-1 NH4NO3, (v) 60 kg N ha-1 cattle manure-N, and (vi) 120 kg N ha-1 cattle manure-N. In China, treatments were; (i) Control, (ii) 300 kg N ha-1 Urea, (iii) 92 kg N ha-1 Urea plus 65 kg ha-1 chicken (Gallus domesticus) manure-N, (iv) 100 kg N ha-1 Urea and (v) 100 kg N ha-1 control release Urea. Our results showed that under both temperate and tropical conditions, integrated nutrient management resulted in lower N2O emissions compared to inorganic fertilizers which had higher total and yield-scale N2O emissions. We conclude that by combining organic and inorganic N sources, smallholder farmers in both China and Zimbabwe, and other countries with similar climatic conditions, can mitigate agricultural emissions without compromising productivity.

Soil fertility management in organic sys- tems, regulated by the organic standards, should seek to build healthy, fertile soils and reduce reliance on external inputs. The use of nutrients from conventional sources, such as animal manures from conventional farms, is currently permitted, with restrictions, in the organic regulations. However, the reliance of organic agriculture on the conventional system is considered problematic. In light of this, the organic sector in Denmark has recently decided to gradually phase out, and ultimately ban, the use of conventional ma- nures and straws in organic agriculture in Denmark. Core focal areas for phasing out conventional nutrients are as follows: (1) amendments to crop selection and rotations, (2) alternative nutrient sources (organic wastes) and (3) increased cooperation between organic livestock and arable farmers. Using Denmark as a case, this article discusses the background and impli- cations of the strategy to phase out conventional ma- nure and straw, and explores possible solutions to the challenge of ensuring a sustainable nutrient supply to organic systems. Alternative strategies to ensure nutri- ent supply will require a tapestry of small solutions. One element of this tapestry is to review the volume and type of nutrient sources available in alternative, non-farm organic waste streams and consider their suitability for use in organic systems.

Soil fertility management in organic systems, regulated by the organic standards, should seek to build healthy, fertile soils and reduce reliance on external inputs. The use of nutrients from conventional sources, such as animal manures from conventional farms, is currently permitted, with restrictions, in the organic regulations. However, the reliance of organic agriculture on the conventional system is considered problematic. In light of this, the organic sector in Denmark has recently decided to gradually phase out, and ultimately ban, the use of conventional manures and straws in organic agriculture in Denmark. Core focal areas for phasing out conventional nutrients are as follows: (1) amendments to crop selection and rotations, (2) alternative nutrient sources (organic wastes) and (3) increased cooperation between organic livestock and arable farmers. Using Denmark as a case, this article discusses the background and implications of the strategy to phase out conventional manure and straw, and explores possible solutions to the challenge of ensuring a sustainable nutrient supply to organic systems. Alternative strategies to ensure nutrient supply will require a tapestry of small solutions. One element of this tapestry is to review the volume and type of nutrient sources available in alternative, non-farm organic waste streams and consider their suitability for use in organic systems.

Crop-based biofuels represent an environmental and political alternative to fossil fuels, as well as an important source of rural development income; as global biofuel markets continue to mature, however, their impact on food security remains controversial. This study investigates the effects of biofuel feedstock adoption by smallholders in the northwestern Cambodian province of Banteay Meanchey, a region undergoing rapid land use change following the formal end of the Khmer Rouge era in 1989 and subsequent rural resettlement. Remote sensing data combined with field interviews pointed to three discrete phases of land use change in this period: first, as a result of the establishment of new settlements (mainly subsistence rice production); second, via the expansion of cash crop cultivation into forested areas (mainly grown on upland fields); and third, due to the response of smallholders to a sharp increase in regional demand for cassava starch (grown exclusively on upland fields). The study found that agricultural expansion due to cassava growing was severe, but it was not the sole contributor to deforestation in the region. The exposure of smallholder economies to the volatile cassava market had severe consequences for livelihoods and food security. The paper concludes with a discussion of the probable impacts of the emerging cassava market on trajectories in land use, land ownership, and land access in rural Cambodia. The case looks at biofuel adoption in the context of other land use changes, but also provides evidence at the local scale of how a strongly market driven crop, in this case biofuel feedstock, can have striking environmental and socioeconomic consequences.

Soil fertility management in organic systems, regulated by the organic standards, should seek to build healthy, fertile soils and reduce reliance on external inputs. The use of nutrients from conventional sources, such as animal manures from conventional farms, is currently permitted, with restrictions, in the organic regulations. However, the reliance of organic agriculture on the conventional system is considered problematic. In light of this, the organic sector in Denmark has recently decided to phase out, and ultimately ban, the use of conventional manures and straws in organic agriculture in Denmark by 2021. Core focal areas for phasing out conventional nutrients are 1) amendments to crop selection and rotations, 2) alternative nutrient sources (organic wastes), and 3) increased cooperation between organic livestock and arable farmers. Using Denmark as a case, this article discusses the background and implications of the decision to ban conventional manure and straw, and explores possible solutions to the challenge of ensuring a sustainable nutrient supply to organic systems. Alternative strategies to ensure nutrient supply will require a tapestry of small solutions. One element of this tapestry is to review the volume and type of nutrient sources available in alternative, non-farm organic waste streams, and consider their suitability for use in organic systems.

The Chapter discusses the efficiency of nutrient and energy use in organic farming, regarding the pressing need to make efficient use of natural resources. Nutrient recycling, the use of adapted plant varieties and energy-saving through the ban of synthetic nitrogen fertilizer are organic farming practices that enhance resource efficiency.

Certified organic agriculture stipulates a range of principles and standards, which govern farmer practices. The recent global expansion of organic agriculture has raised new challenges for organic agriculture, particularly whether management practices in organic farms are subject to the forces of conventionalisation. We studied changes in agroecological practices in certified organic farms in China, Brazil and Egypt. The study takes departure in the conventionalisation hypothesis and the analysis is framed using organic and agroecological principles. The study focuses on agroecological design principles, inherent to organic agriculture, of diversity in crop production, pest, disease and weed management, and soil fertility management. The research design was as a multiple case study of five cases in China, Brazil and Egypt. We show that the adoption of organic agriculture has induced fundamental changes in organic farmer management practices, although agroecological practices of organic farmers do not fulfil organic principles. The forces of conventionalisation exert a strong influence on changes in organic farmer practices. Organic ‘niche’ market crops with a high-value influence organic farmers’ management decisions, particularly regarding the prioritisation of diversity in the cropping systems for agroecological purposes. The farming systems have therefore not undergone major changes of their cropping patterns. Furthermore, there was a general heavy reliance upon input substitution for pest and soil fertility management. This study thus presents new data and a novel analysis of the implications at the farm scale of the global expansion of organic agriculture, and the influence of conventionalisation on farmers practices.

This Study was undertaken to evaluate the effect of organic certification to the livelihoods of rural organic farmers in Uganda. It was taken in two villages; Bwaziba and Lusanja of Luwero district in central Uganda. In each village both the treatment and control group (the certified and non-certified organic farmers) were sampled. Exporting companies were interviewed on certification issues and their outgrowers. Information about organic farmers was also collected from various institutions. Participatory Rural Appraisal exercise (matrix ranking) was used to determine the reasons why farmers grow organically, the benefits and challenges the farmers faced in organic agriculture and certification. This was followed by administration of 120 survey questionnaires to the two farmer¿s household based on random sampling from the list of farmers provided by the exporting companies. Face-to-face semi-structured interviews with prepared interview guides were then conducted with purposively sampled study households. In addition two certifying bodies (IMO and UgoCert) currently operating and have office in Uganda were interviewed. Data collected was analyzed and some statistical tests were run to show the level of significance differences between the two households. The research shows that there are significant differences in some of the livelihood components of both certified and non certified household before and after certification. Certified organic farmers benefit from the sales of their organically certified products which are sold into the international market through their activity as contract farmers (outgrowers) to different exporting companies. High certification cost, inability of the exporting companies to purchased all the organically grown crops by farmers and the incessant changing of standards requirements are among the challenges of organic certification as obse

The need for enhancing food production and availability in underprivileged regions of the world requires the attention of scientists. This paper explores the possibilities for rethinking Agricultural Research for Development (AR4D) in the light of new challenges characterized by a high degree of scientific uncertainty and associated with intense political differences of interest. New challenges that particularly influence food production in underprivileged regions include global climate change, globalisation of food chains, and emerging low-carbon energy systems. We argue that by applying the people-centred Sustainable Livelihoods Approach as a research paradigm in AR4D, researchers may be more successful in producing knowledge that is useful to entrepreneurial smallholder farmers. Without such rethinking, traditional scientific approaches and logic may limit the contribution that agricultural AR4D can make toward the achievement of the Millennium Development Goals of halving extreme hunger by 2015 and improving the livelihoods of all.

Increased demand for certified organic products has led to an increase in the number of certified organic farms in developing countries. Knowledge of farmer nutrient management practices on certified organic farms in developing countries is limited. Thus, the aim of this study was to investigate the impact of the adoption of certified organic agriculture on farm nutrient flows and nutrient budgets, and evaluate to which degree organic farms comply with organic principles relating to nutrient management. The study is based on five case studies of different types of certified organic farming systems in Brazil, Egypt and China. Farm nutrient flows and nutrient budgets for nitrogen, phosphorous and potassium were created for each farm. Four of the five organic systems studied had nutrient surpluses on the farm budget. The surpluses were of varying magnitude. The main difference between organic and nonorganic farm nutrient flows was the replacement of mineral fertilizers with organic inputs. However, the magnitude of nutrient flows were generally similar for organic and non-organic farms. Certified organic farms with positive nutrient budgets had a heavy reliance on external inputs. Continued high dependence on an external supply of nutrients, which typically originate from mineral sources, poses a significant challenge to organic farmers’ fulfilment of the principles of organic agriculture.

The article argue that the livelihood approach is relevant for Research in sub-saharan African food systems, which must address post-sustainability challenges and increase developmental returns

maintains the focus on salience, legitimacy, and credibility in the research.