Supported by policy-makers and non-governmental organizations (NGOs), coffee farmer organizations obtain organic and Fairtrade certifications to upgrade their coffee and, thus, increase returns to their members. Whether this and other upgrading strategies fit into the business model of the cooperative and lead to success are often not considered. This research aims to identify similarities and differences between conventional and certified cooperatives and the resultant impact on farmers' incomes. We analyze the business models, upgrading strategies, and strengths, weaknesses, opportunities and threats (SWOT) of seven conventional, organic and Organic-Fairtrade certified coffee cooperatives and link these to members' coffee gross margins. We use data from over 100 in-depth qualitative interviews and a household survey of 327 cooperative members in northern Nicaragua. Results indicate that cooperatives often apply the same upgrading strategies despite very different business models and SWOT. There are also many commonalities of SWOT among cooperatives but no clear-cut differences between conventional, organic and Organic-Fairtrade certified cooperatives. The qualitative comparison of coffee gross margins among the cooperatives shows no clear income effect from participating in certified coffee production and certified cooperatives. It indicates, rather, dependence of gross margins on yield levels, the business model and upgrading strategies of the cooperatives. Upgrading through certification seems only successful with a suitable business model and other upgrading strategies. Policies should focus on (i) increasing as well as stabilizing coffee yields, and (ii) on the institutional framework of cooperatives by offering strategic support, credit access, external auditing of cooperatives and the establishment of a functional national coffee institute.

Agriculture in general and intensive animal production in particular can degrade the environment, especially as a consequence of the overuse of nutrients. Intensively grazed dairy systems, defined by the presence of foraging animals in the landscape, are often considered a more benign approach to dairy production with perceived smaller impacts due to the reduced requirement for manure disposal. However, grazing dairy cows contribute nutrients and pathogens in excreta, and sediment through landscape deformation. These impacts can dramatically increase in parts of the farm such as feeding, watering and sacrifice areas, laneways and night paddocks where animals are concentrated and spend a disproportionate amount of time. Other practices such as the disposal of dairy shed or dairy factory effluent and cultivation of fodder crops can also pollute the environment. A common approach to reduce nutrient, pathogen and sediment losses from dairy farms is to establish buffer zones in riparian areas that act as an interface between upland land use and waterways. This is generally done by fencing riparian areas to exclude stock and revegetating with understory and overstory species, with the aim of increasing infiltration, trapping sediment and decreasing contaminant losses from upland pastures. However, poorly designed and managed riparian areas may themselves contribute to further environmental degradation. Rarely is an integrated approach, including factors such as animal behavior and dairy farm management practices, as well as an analysis of landscape and riparian hydrology used in developing riparian management recommendations for individual farms. This paper reviews the threats posed by intensively grazed dairy systems, approaches to improve riparian zone management and recommends future research needs.

Soil testing strategies that include biologically based indicators in organic and alternative farming systems are needed in order to improve recommendations that balance production and environmental goals. In this study, soil samples were collected before and after soils were transitioned from conventional row crop production to organic management using rotations that varied in both their inputs and tillage intensity. Ley-, row crop- and vegetable-based farming systems were implemented using locally specific production practices. Subplots were imposed within each system to allow comparison of farming systems without amendment and with dairy manure- and compost-amendment. Soil analyses included standard chemical tests (0–15 cm) for available phosphorus, exchangeable potassium, calcium, magnesium, pH, total organic carbon (SOC) and total nitrogen (TN). Biological assays (0–15 and 15–30 cm) included particulate organic matter-C and -N (POM-C, POM-N), soil and POM C:N ratios, fluorescein diacetate (FDA) hydrolysis, potentially mineralizable N (PMN) and hydrolysable amino-N + NH4 (IL-N). Even though cropping and tillage intensity varied among systems (ley < row crop < vegetable), organic matter and nutrient reserves were not statistically different. Nutrient concentrations tested medium to high, even without compost or manure application. Labile fractions of soil organic matter were more enriched in the deeper sampling depth; whereby, POM stocks within the 15–30 cm depth increased by 20% on average compared to roughly 6% in the surface depth. This and observed changes in other properties demonstrate the multiple benefits derived from use of winter annual or perennial crops. Results from our analyses suggested PMN and POM have particular promise as metrics of change in commercial soil testing facilities to assist recommendations for amendments to balance production and environmental goals.

Ecosystem functions and services provided by soils depend on land use and management. The objective of this article is to review and synthesize relevant information on the impacts of no-till (NT) management of croplands on ecosystem functions and services. Sustainable management of soil through NT involves: (i) replacing what is removed, (ii) restoring what has been degraded, and (iii) minimizing on-site and off-site effects. Despite its merits, NT is adopted on merely ∼9% of the 1.5 billion ha of global arable land area. Soil's ecosystem services depend on the natural capital (soil organic matter and clay contents, soil depth and water retention capacity) and its management. Soil management in various agro-ecosystems to enhance food production has some trade-offs/disservices (i.e., decline in biodiversity, accelerated erosion and non-point source pollution), which must be minimized by further developing agricultural complexity to mimic natural ecosystems. However, adoption of NT accentuates many ecosystem services: carbon sequestration, biodiversity, elemental cycling, and resilience to natural and anthropogenic perturbations, all of which can affect food security. Links exist among diverse ecosystem services, such that managing one can adversely impact others. For example, increasing agronomic production can reduce biodiversity and deplete soil organic carbon (SOC), harvesting crop residues for cellulosic ethanol can reduce SOC, etc. Undervaluing ecosystem services can jeopardize finite soil resources and aggravate disservices. Adoption of recommended management practices can be promoted through payments for ecosystem services by a market-based approach so that risks of disservices and negative costs can be reduced either through direct economic incentives or as performance payments.

Trials in farmers' field(s) were conducted to study the usefulness of vermicompost (VC) produced from distillation waste of menthol mint (Mentha arvensis L. cv. Kushal) using earthworms (Eisenia foetida) in reducing the inputs of chemical fertilizers and improving soil health in menthol mint-based cropping systems. Results of the first trial conducted on menthol mint (sole crop) in the fields of 45 farmers clearly indicated that 75% of the chemical fertilizer inputs can be reduced by supplementing the fields with 5tha−1 of menthol mint VC leading to higher levels of profits to the farmers by significantly improving herb and oil yield (6.7 and 8.4%, respectively) compared to the full recommended dose of chemical fertilizers (NPK 75:60:60kgha−1). The second trial was conducted in the fields of six farmers adopting a menthol mint cropping system (mint–rice–wheat–mint) where significantly higher yields were recorded in plots supplemented with 5tha−1 of menthol mint VC+25% of the recommended dose of chemical fertilizers; an increase of 5.6–7.2% in mint oil and 6.6% in wheat yield over the plots receiving the full recommended dose of chemical fertilizers (NPK 75:60:60kgha−1). However, in the case of rice, the highest grain yield was observed within plots receiving the full recommended dose of chemical fertilizers. Data obtained on soil properties clearly showed that apart from enhancing the yields of crops, the integration of VC with chemical fertilizers considerably improved the soil fertility/sustainability status in terms of organic carbon, available N, P and K.

Since the early 1980s organic agriculture has undergone enormous growth and innovation in the US and throughout the world. Some observers have pointed to the US Department of Agriculture's 1980 Report and Recommendations on Organic Farming as having provided the catalyst for many of these developments. It is important, however, to understand how the evolving character of organic ideology during the 1960s and 1970s helped lay the foundation for moving organic agriculture onto the US governmental agenda in the early 1980s. We explore these and other contextual factors surrounding the USDA Report's release, including its methods, findings and recommendations, and both positive and negative reactions, as well as those factors that led to the Report's declining influence by the decade's end. The need for agricultural sustainability has played an important role in shaping, not only the path of organic agriculture in the US but also the overall politics of American agriculture. Legislative efforts to support organic agriculture have evolved along with this altered policy environment and are considered here within the broader context of the politics of sustainable agriculture. Next, we consider the organic industry's transition from a privately managed enterprise to the pivotal role now played by the federal government in the administration of the National Organic Program. Calls to move ‘beyond organic’ are also examined. Finally, we explore the impact of sustainable agriculture, agricultural research and farm structure upon the future of organic agriculture in the US. The politics within these three interrelated domains of public agricultural policy will likely bear heavily upon the future of organic farming and the organic industry as a whole.

Cropping systems that include forage legumes and small grains in addition to corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] can achieve similar or higher crop productivity and economic return than simpler corn–soybean rotations. We hypothesized that this rotation effect occurs regardless of the crop genotype planted and the herbicide and cultivation regime selected for weed management. To test this hypothesis, we conducted a 3-year experiment that compared three cropping systems: a conventional 2-year corn–soybean rotation, a 3-year corn–soybean–oat (Avena sativa L.)/red clover (Trifolium pretense L.) rotation, and a 4-year corn–soybean–oat/alfalfa–alfalfa (Medicago sativa L.) rotation. Within each cropping system, two contrasting sets of management strategies were used: (i) genetically engineered corn with resistance to insect pests (Ostrinia nubilalis Hübner and Diabrotica spp.) plus the broadcast application of pre-emergence herbicides, followed in the rotation by a genetically engineered soybean variety with resistance to the herbicide glyphosate plus the post-emergence broadcast application of glyphosate; and (ii) non-genetically engineered corn plus the banded application of post-emergence herbicides, followed in the rotation by a non-genetically engineered soybean and banded application of several post-emergence herbicides. The two management strategies were identified as ‘GE’ and ‘non-GE.’ Corn yield was higher in the 3-year (12.51Mgha−1) and 4-year (12.79Mgha−1) rotations than in the conventional 2-year (12.16Mgha−1) rotation, and was also 2% higher with the GE strategy than with the non-GE strategy. Soybean yield was similar among rotation systems in 2008, but higher in the 3- and 4-year systems than the 2-year rotation in 2009 and 2010. Soybean yield was similar between management strategies in 2008, but higher in the GE strategy in 2009, and similar between strategies in the 3- and 4-year rotations in 2010. Increases in rotation length were accompanied by 88–91% reductions in synthetic N fertilizer application, and the use of the non-GE rather than the GE strategy was accompanied by a 93% reduction in herbicide active ingredients applied. Averaged over the period of 2008–2010, net returns to land and labor were highest for the 3-year rotation managed with either the GE ($928ha−1yr−1) or non-GE ($936ha−1yr−1) strategies, least in the 2-year rotation managed with the non-GE strategy ($738ha−1yr−1), and intermediate in the other rotation×management combinations. Our results indicate that more diverse crop rotation systems can be as profitable as conventional corn–soybean systems and can provide farmers with greater flexibility in crop management options.

Agriculture in the US Corn Belt is under increasing pressure to produce greater quantities of food, feed and fuel, while better protecting environmental quality. Key environmental problems in this region include water contamination by nutrients and herbicides emitted from cropland, a lack of non-agricultural habitat to support diverse communities of native plants and animals, and a high level of dependence on petrochemical energy in the dominant cropping systems. In addition, projected changes in climate for this region, which include increases in the proportion of precipitation coming from extreme events could make soil and water conservation in existing cropping systems more difficult. To address these challenges we have conducted three cropping systems projects in central Iowa: the Marsden Farm Cropping Systems experiment, the Science-based Trials of Row-crops Integrated with Prairies (STRIPs) experiment, and the Comparison of Biofuel Systems (COBS) experiment. Results from these experiments indicate that (1) diversification of the dominant corn–soybean rotation with small grains and forage legumes can permit substantial reductions in agrichemical and fossil hydrocarbon use without compromising yields or profitability; (2) conversion of small amounts of cropland to prairie buffer strips can provide disproportionately large improvements in soil and water conservation, nutrient retention, and densities of native plants and birds; and (3) native perennial species can generate large amounts of biofuel feedstocks and offer environmental benefits relative to corn- and soybean-based systems, including greater carbon inputs to soil and large reductions in nitrogen emissions to drainage water. Increasing biodiversity through the strategic integration of perennial plant species can be a viable strategy for reducing reliance on purchased inputs and for increasing agroecosystem health and resilience in the US Corn Belt.

Proper sulfur management in winegrapes may potentially reduce both insecticide/miticide use and the human/social problems associated with sulfur's impacts on air quality and odors, particularly in wine tourism regions. Data from California's unique Pesticide Use Report (PUR) database, which records agricultural pesticide applications on all crops throughout the state, are used to determine if either winegrape grower's choice of sulfur formulation (dust only, wettable only, or a combination) or overall sulfur use rates (pounds per acre planted) correlate with annual miticide and insecticide use in Fresno and Madera (hotter–drier) and Napa and Sonoma counties (cooler–damper). Annual sulfur use has declined by 36–55% in these counties from 1993 to 2009. In 2000, the greatest number of growers in each county were combination users; wettable users were higher in Napa (38%) and Sonoma (34%) than in Fresno (24%) and Madera (10%); and dust-only users varied little (15–19%) across the four counties. Data for 2005 and 2009 showed similar trends. The use of high-toxicity insecticides in Fresno was 387% higher than in Napa–Sonoma in 2000, but was 25 and 8% lower in 2005 and 2009, respectively. In Fresno, wettable sulfur users used less high-toxicity insecticides; while in Fresno and Madera dust users used less lower-risk insecticides than combination or wettable sulfur users. No significant differences in insecticide use were evident between the three sulfur use categories in Napa–Sonoma (P = 0.97). On average, dust users in Fresno–Madera used more high-toxicity miticides than combination or wettable sulfur users in 2000. That trend decreased in the data for 2005 and 2009. Average miticide use in Fresno–Madera was higher than in Napa–Sonoma by 1349% in 2000, 1103% in 2005 and 146% in 2009. Higher sulfur use intensities among individual growers in Fresno–Madera were positively correlated with greater use of high-toxicity miticides in 2000 and 2005, but not 2009. The comparable results for Napa–Sonoma were less clear. Since PUR data represent statewide information on pesticide use decisions in real-world farming scenarios, it can complement data from field and laboratory studies. Expanding these analyses to compare pesticide use by individual growers across years, or to correlate pesticide usage with any published mite field surveys may shed more light on the enigmatic relationship between sulfur fungicide use and mite outbreaks in winegrapes.

Despite an overall growth rate of the organic farming sector in the European Union, a considerable number of farmers cease organic production each year. Given the commitment of many European governments to increase the size of their organic farming sectors, reducing the rate of withdrawals from organic production may be an easier option than attracting new farmers into organic farming. In order to reduce the rate of withdrawals, knowledge about those farmers is required. However, to date, little is known about farmers who adopt and subsequently abandon organic farming. This study attempts to fill this gap in the literature by comparing and contrasting the farm and personal characteristics of organic, former organic and conventional farmers. To this end, primary data from 596 Irish cattle and sheep farmers are utilized. Overall, the findings reveal significant differences between the three groups. More specifically, organic farmers are found to be the most environmentally aware farmers, who also rate information gathering as more important than the remaining two groups. Organic farmers are younger, better educated and more likely to be women than conventional farmers. Former organic farmers stand out to be the least risk averse group and also express lower environmental awareness than organic farmers. Conventional farmers are found to be the most profit oriented and least environmentally aware group. In addition, this group farms more intensely stocked enterprises than the remaining groups. The paper concludes with a discussion of some policy recommendations aimed at increasing the size of the organic sector.

Conservation agricultural systems rely on three principles to enhance ecosystem services: (1) minimizing soil disturbance, (2) maximizing soil surface cover and (3) stimulating biological activity. In this paper, we explore the concept of diversity and its role in maximizing ecosystem services from managed grasslands and integrated agricultural systems (i.e., integrated crop–livestock–forage systems) at the field and farm level. We also examine trade-offs that may be involved in realizing greater ecosystem services. Previous research on livestock production systems, particularly in pastureland, has shown improvements in herbage productivity and reduced weed invasion with increased forage diversity but little response in terms of animal production. Managing forage diversity in pastureland requires new tools to guide the selection and placement of plant mixtures across a farm according to site suitability and the goals of the producer. Integrated agricultural systems embrace the concept of dynamic cropping systems, which incorporates a long-term strategy of annual crop sequencing that optimizes crop and soil use options to attain production, economic and resource conservation goals by using sound ecological management principles. Integrating dynamic cropping systems with livestock production increases the complexity of management, but also creates synergies among system components that may improve resilience and sustainability while fulfilling multiple ecosystem functions. Diversified conservation agricultural systems can sustain crop and livestock production and provide additional ecosystem services such as soil C storage, efficient nutrient cycling and conservation of biodiversity.

Integrated pest management (IPM) has been very successful in directing farming to a more environment-friendly production. It is a great tool for producers in transition to organic farming. However, the extent of its economic impact is not well understood by farmers. This study looks at the amount of savings and potential market profitability of using IPM in South Carolina collard production considering alternative scouting methods. Scouting is an essential part of IPM that is usually ignored. This analysis presents a comparative assessment of the merits of conventional sampling (CS) and binomial sequential scouting method (SSM). SSM is a recently developed scouting system for traditionally operated collard farms that is geared toward a more economical execution of scouting without forfeiting the effectiveness of the process. Financial analytical tools, specifically costs and returns methods and sensitivity analysis on prices, were utilized to determine the economic advantages or disadvantages of the two methods. Outcomes indicate that both scouting methods would result in cost savings if used on traditionally operated farms. Particularly, the cost savings per hectare generated from IPM with SSM [3.62% of total cost (TC) and 3.91% of total variable cost (TVC)] is higher than the cost savings from IPM with CS (2.91% of TC and 3.15% of TVC). The difference in cost savings between IPM with CS and IPM with SSM basically came from the less scouting time of SSM that entailed lower labor cost for the farm. Therefore, to attain maximum profitability potential, using IPM with the SSM is a better option. Some may conjecture that the cost savings were insignificant due to the low percentages in cost savings. However, its importance is evident at the potential savings per farm and at the aggregate/state level.

Sustainable intensification of smallholder farms in Africa is highly dependent on enhancing biological nitrogen fixation (BNF). Legume diversification of maize-based systems is a core example of sustainable intensification, with the food security of millions of farm families at stake. This study highlights the constraints and opportunities associated with the adoption of legumes by smallholder farmers in southern Africa. A two-part survey of households and farm fields (n=88) was conducted in the Ekwendeni watershed of northern Malawi. Participatory research and education activities have been underway for over a decade in this region, resulting in expanded uptake of a range of legume species as intercrops and in rotation with the staple maize crop. Farmer adoption has occurred to a varying extent for soybean (Glycine max), pigeon pea (Cajanus cajan), velvet bean (Mucuna pruriens) and fish bean (Tephrosia vogelii). Farmers, working with the project valued pigeon pea and other legumes for soil fertility purposes to a greater extent than farmers not working with the project. Legumes were valued for a wide range of purposes beyond soil cover and fertility enhancement, notably for infant nutrition (at least for soybean), insect control, and vegetable and grain production for both market and home consumption. Literature values for BNF in tropical legumes range up to 170 kg N ha−1 for grain and 300 kg N ha−1 for green manure species; however, our field interviews illustrated the extent of constraints imposed by soil properties on smallholder fields in Malawi. The key edaphic constraints observed were very deficient to moderate phosphorus levels (range 4–142, average 33 mg kg−1), and moderately acid soils (range pH 5.1–7.9, average 6.2). The per farm hectarage devoted to legume production relative to maize production was also low (0.15 versus 0.35 ha), a surprising find in an area with demonstrated interest in novel legume species. Further, farmers showed a strong preference for legumes that produced edible grain, regardless of the associated nutrient removal in the harvested grain, and did not sow large areas to legume crops. These farm-level decisions act as constraints to BNF inputs in maize-based smallholder cropping systems. Overall, we found that legume productivity could be enhanced. We documented the value of policies and educational efforts that support farmers gaining access to high-quality seeds, amendments for phosphorus-deficient soils, and promotion of multipurpose legumes that build soils through leafy residues and roots, as well as providing grain for food security and sales.

Chickpea (Cicer arietinum L.) is an economically and ecologically important food legume crop. Ethiopia has a large collection of chickpea germplasm accessions; but, it has not been extensively characterized for desirable sources of agronomic and symbiotic significance for use in breeding programs. A study was conducted at two locations (Ambo and Ginchi) in 2009/2010 to characterize and evaluate Ethiopian chickpea germplasm accessions for symbiotic and agronomic performance. One hundred and thirty-nine germplasm accessions were evaluated with 16 other genotypes including non-nodulating reference checks. Differences among genotypes, locations and genotype by location interaction effects were significant for a number of characters. A number of accessions better performing over the improved genotypes were identified for both symbiotic and agronomic characters. The amount of fixed nitrogen ranged from 13 to 49% in foliage, 30 to 44% in grain and 28 to 40% in total above-ground biomass. Grain yield performance varied from 31 to 70 g per 5 plants and seed size ranged from 82 to 288 g per 1000 seeds. For both symbiotic and agronomic characters, landraces were found to be overwhelmingly superior to introduced genotypes, except for seed size, where the best genotypes were all from exotic sources. The result indicated that Ethiopian chickpea landraces have better genetic potential for improving a number of symbiotic and agronomic characters over the varieties currently in use. Selection of best individuals within and among the accessions would be expected to be effective.

Organic grain cropping systems can enhance a number of ecosystem services compared with conventional tilled (CT) systems. Recent results from a limited number of long-term agricultural research (LTAR) studies suggest that organic grain cropping systems can also increase several ecosystem services relative to conventional no-till (NT) cropping systems: soil C sequestration and soil N fertility (N mineralization potential) can be greater while global warming potential (GWP) can be lower in organic systems that use animal manures and cover crops compared with conventional NT systems. However, soil erosion from organic systems and nitrous oxide (N2O, a greenhouse gas) emissions from manure-based organic systems appear to be greater than from conventional NT systems, though data are limited. Also, crop yields, on average, continue to be lower and labor requirements greater in organic than in both tilled and NT conventional systems. Ecosystem services provided by organic systems may be improved by expanding crop rotations to include greater crop phenological diversity, improving nutrient management, and reducing tillage intensity and frequency. More diverse crop rotations, especially those that include perennial forages, can reduce weed pressure, economic risk, soil erosion, N2O emissions, animal manure inputs, and soil P loading, while increasing grain yield and soil fertility. Side-dressing animal manures in organic systems may increase corn nitrogen use efficiency and also minimize animal manure inputs. Management practices that reduce tillage frequency and intensity in organic systems are being developed to reduce soil erosion and labor and energy needs. On-going research promises to further augment ecosystem services provided by organic grain cropping systems.

Ecologically based farming conserves and improves the soil resource and protects environmental quality by using organic or natural resources without the application of synthetic chemicals. Soil quality assessment indicates the ability of management systems to optimize soil productivity and to maintain its structural and biological integrity. Our objective was to evaluate the effect of ecologically based management on biochemical characteristics of soil [soil quality indicators (SQI)] as an assessment of soil quality. The study was conducted on an ecologically based farming enterprise established on gently sloping soils of Sharpsburg silt loam (fine montmorillonitic, mesic Typic Argiudolls) in Clay County, Missouri, which was previously under conventional corn and soybean production. The transition to organic farming began in 1995, which included a primary management strategy to restore soil organic matter consisting of the establishment of native prairie plants and the application of composted vegetative residues and litter from horse and laying hen operations. Soils were collected at 0–10cm depths from sites under organic production (orchard and vegetable), managed prairie/pasture and from adjacent unmanaged fields during 2003–2008 for soil quality assessment. Soil organic carbon (SOC) and water-stable soil aggregates were considerably increased by up to 60 and 72%, respectively, in organic production sites compared with tilled cropland by the fifth year of assessment. Organically managed systems and restored prairie sites significantly increased (P<0.05) soil enzyme activities compared with unmanaged grass and tilled cropland. For example, dehydrogenase and glucosaminidase activities increased by 60 and 73%, respectively, under organic vegetables compared with tilled cropland. Soil enzyme activities were significantly correlated with SOC content (r values up to 0.90, P<0.001). The results of the soil quality assessment suggest that ecologically based management successfully restored biological activity of silt loam soils previously under intensive conventional agriculture. The system practiced at the study sites illustrates how resources internal to the farm (i.e., composts) can be used to manage soil productivity.

Potato production in several Mediterranean countries is focused on the ‘early’ crop type, and is generally associated with intensive applications of farming inputs. Here we report, for the first time, a comparison of crop performance between organic and conventional cultivation systems. Three cultivars were tested over two seasons (2007 and 2008) to record their phenology, yield and tuber chemical composition. The organic cultivation system was less productive than the conventional one across both years with respect to total yield, but in the season (2008) when late blight infection was not severe the difference was narrowed from 7% (Ditta) to 20% (MN 2-1577 S1). The Italian breeding clones (MN 1404 O5 and MN 2-1577 S1) deserve specific consideration due to their higher total yield and nutritional value (in terms of total protein and vitamin C content) under organic cultivation system than the cultivar Ditta. In addition, the organic farming produced tubers with a lower nitrate content, an important benefit in the context of human health. In conclusion, our results indicate that organic cultivation of ‘early’ potatoes can deliver acceptable agronomic and qualitative performances. However, the response of the ‘early’ crop potato to organic farming depends upon both seasonal conditions and cultivar choice. In particular, the selection of appropriate cultivars is one of the key aspects to optimize this environmentally friendly production system.

Conservation agriculture (CA) systems are based upon minimal soil disturbance; crop residue retention and crop rotation and/or intercrop association are increasingly seen to recycle nutrients, increase yield and reduce production costs. This study examines the effects of CA practices on crop productivity, profitability and soil quality under the conditions encountered by smallholder farmers in two farming communities from 2005 to 2011 in Malawi, as part of the contribution to remedy a lack of supporting agronomic research for these relatively new systems. The drier agroenvironment of Lemu of Bazale Extension Planning Area (EPA) is characterized by sandy clay loam soils and lower rainfall. Here, CA showed positive benefits on maize yield after the first season of experimentation, with highest increases of 2.7 Mg ha−1 and 2.3 Mg ha−1 more yield in CA monocrop maize and CA maize–legume intercrop, respectively, than the conventional tillage in the driest season of 2009/10. In the high rainfall environment of Zidyana EPA (characterized by sandy loam soils), substantial maize yield benefits resulted in the fifth season of experimentation. Farmers spent at most 50 days ha−1 (US$140) producing maize under CA systems compared with 62 days ha−1(US$176) spent under conventional tillage practices. In Lemu, both CA systems resulted in gross margins three times higher than that of the conventional control plot, while in Zidyana, CA monocrop maize and CA maize–legume intercrop resulted in 33 and 23% higher gross margins, respectively, than conventional tillage. In Zidyana, the earthworm population was highest (48 earthworms m−2 in the first 30 cm) in CA monocrop maize, followed by a CA maize–legume intercropping (40 earthworms) and lowest (nine earthworms) in conventionally tilled treatment. In both study locations CA monocrop maize and CA maize–legume intercrop gave higher water infiltration than the conventional treatment. Improvements in crop productivity, overall economic gain and soil quality have made CA an attractive system for farmers in Malawi and other areas with similar conditions. However, for extensive adoption of CA by smallholder farmers, cultural beliefs that crop production is possible without the ubiquitous ridge and furrow system and residue burning for mice hunting have to be overcome.