Greater London has a vibrant food scene comprising of many different types of urban and peri-urban ‘short food supply chains’ (SFSCs). This paper reports on exploratory research, which used examples of SFSCs from London to build a more detailed understanding of different types of urban SFSC and their relative performance compared to each other. To do this, we undertook a participatory sustainability impact assessment (SIA) in which local food system stakeholders were asked to rank the perceived impacts of five different urban and peri-urban SFSCs compared with the current ‘mainstream’ food supply system (defined as supermarkets retailing mass-produced, standardized food products). The SFSCs ranked were: (1) urban gardening (self-supply), (2) urban gardening (commercial), (3) community supported agriculture (CSA), (4) direct sale (on-farm) and (5) direct sale (off-farm). Results from the SIA showed that CSAs were regarded as delivering the highest overall social, economic and environmental benefits, followed by urban gardening (commercial), urban gardening (self-supply) and direct sales (off-farm). The lowest overall rating was for the supply chain direct sales (on-farm). All five SFSCs were ranked highest on the social aspects of sustainability. Following the participatory SIA of perceived sustainability, we next developed a questionnaire in order to test the feasibility of measuring the specific (rather than ‘perceived’) impacts of an urban SFSC. We applied the test at a community-led local food market in South London, where we conducted face-to-face interviews with all market stallholders (18 respondents) and a random sample of consumers (51 respondents). Results from the community-led market were similar to those acquired at the SIA workshop, with greater agreement about the social benefits of the market, compared with economic and environmental impacts. The results also suggest that producers underestimated consumers’ willingness to share the risks that the producers face and we identify this as an important aspect for future research. The paper concludes with reflections on the strengths and weaknesses of the SIA methodology.

This paper uses the framework of the Just–Pope production function to evaluate the impacts of climate change on yields of the rainfed Aman rice crop in Bangladesh. It analyses disaggregated district-level data on climate variables and Aman rice yield over a 48 year time horizon. The results reveal that changes in maximum temperatures have had positive and negative effects on yield in the linear and quadratic functional forms, respectively. However, the elasticity values in the variance function confirm that maximum temperature is risk-increasing for Aman rice while minimum temperature is likely to decrease yield variability. Rainfall has become risk-increasing for Aman rice. Based on three climate change scenarios, this paper also reveals that future climate change is expected to increase the variability of Aman rice yields. Finally, statistically significant dummies for different in-country climate zones require zone-specific adaptation policies to reduce the adverse impacts of climate change.

Manipulation of organic wastes and their composts as a source of organic matter (OM) and nutrients is imperative for sustainable agriculture. Further, the fortification of composts with chemical fertilizer enhances agronomic effectiveness of both by reducing the amount of fertilizer and improving the quality of compost. The present study aimed to explore the potential of organic and chemical nutrient sources with their optimal application and integration for sustainable wheat production. Accordingly, waste fruits and vegetables were collected, dried, ground and processed in a composting vessel. During the enriched composting, waste material (300 kg) was fortified with 30 kg N, i.e. 25% of the standard rate (120 kg N ha−1) of N fertilizer. Treatments for both greenhouse and field experiments using wheat (Triticum aestivum L.) included: control (without any compost or N fertilizer), compost (non-enriched), fertilizer N 120 (120 kg N ha−1), nitrogen-enriched compost (NEC), NEC+N 30 (30 kg N ha−1) and NEC+N 60 (60 kg N ha−1). Application rate of composts (non-enriched or enriched) was 300 kg ha−1 in the respective treatments. Phosphorus and potassium fertilizers were applied at 90 kg P2O5 ha−1 and 60 kg K2O ha−1, respectively in all treatments. The crop was grown to maturity, and data on wheat growth and yield attributes were recorded. Application of NEC significantly improved the growth, yield and N, P and K contents of wheat compared with compost and control treatments. The performance of NEC+N 60 was statistically similar to that of fertilizer N 120. Economic analysis also revealed the superiority of NEC+N 60 over other treatments in terms of net return and relative increase in income; however, the value/cost ratio was highest with NEC alone. For effective and economical use of N fertilizer, it is suggested to integrate N fertilizer at reduced rates with NEC. Through enriched compost, application rates can be decreased from tonnes to kilograms per hectare, and dependence on chemical fertilizer can be reduced to a certain extent. So the approach is farmer friendly as it lowers compost application rates, and is economically acceptable as it saves N fertilizer. It is also environmentally sustainable due the recycling of organic waste and possible reduction of N losses to the environment. Thus, the study has wide application in the global environment and fertilizer market.

Organic agriculture is being promoted in Iran to address environmental problems resulting from the use of chemical materials in agriculture. Despite many advantages of organic agriculture, the results of several case studies show that its adoption rate is still very low among farmers. The purpose of this paper is to review previous studies that investigated the main factors influencing and challenging the adoption of organic agriculture. The review included journal articles and conference papers from 2007 to 2012. The results show that Iranian farmers have strong motives for the adoption, yet face challenges in certifying, marketing, and accessing reliable technical information and credits. Given the review of factors that govern farmers' adoption of organic agriculture, key mechanisms for promoting farmers' adoption are discussed. Further research is needed to learn how to bring these mechanisms into play in Iran.

Traditional African vegetables have recently received considerable attention for their contribution to food and nutrition security and opportunities for enhancing smallholder livelihoods. Promoting the production and consumption of traditional vegetables is expected to enhance household nutrition among urban and rural households. The Good Seed Initiative (GSI) program promoted production and consumption of nutrient-dense traditional African vegetables in Arusha region in Tanzania to reduce malnutrition through diet diversification. We estimated the impact of promotion activities on households, women, and children's dietary diversity. The study used cross-sectional data from 258 and 242 households in intervention and control regions, respectively, and applied matching techniques and inverse probability weighting to control for unobserved heterogeneity and selection bias, which could otherwise bias the outcome estimates. We found that households benefiting from traditional vegetable promotion and demand creation activities had significantly higher dietary diversity of children under 5 yr and women in reproductive age. We found no significant impact of promotion activities on households’ dietary diversity. The policy implication is that scaling up promotional and demand creation activities to encourage consumers to grow and eat traditional African vegetables would be an important element in initiatives to increase dietary diversity, particularly for children under 5 and women in Tanzania.

With increasing urbanization and environmental degradation, urban landscapes are increasingly expected to provide a wide range of ecosystem services typically associated with rural areas, including biodiversity conservation and food production. Because residential landscapes constitute the largest single urban land use, domestic gardens have emerged as a topic of research interest and planning concern. The ecosystem services (or disservices) these landscapes provide, however, have not been rigorously measured, nor have tradeoffs between the services they provide been assessed. In this study, semi-structured interviews were conducted with 59 African American, Chinese-origin or Mexican-origin households with on-lot or vacant lot food gardens in Chicago. Crop plants and cultivated ornamental plants on the lot were inventoried and mapped at the species level. A total of 123 edible plant taxa from 25 families and 288 ornamental plant species from 85 families were identified, for a combined total of 387 species from 90 families. Cumulatively, the gardens of African American households were relatively rich in ornamental plant species and families, while those of Chinese-origin households had a depauperate flora. Crop plant richness was more even across sample types. Shade trees and a developed shrub layer were absent from most gardens, possibly representing a tradeoff in ecosystem services in favor of food production. The richness of the aggregate 2.1 ha of residential property inventoried in this study was comparable with or exceeded that of a 34 ha prairie remnant west of Chicago. However, only 35 (9.6%) of the inventoried species were native to the Chicago area.

While plains favorable to agriculture are still dominated by specialized and intensive agriculture, self-sufficient mixed crop-dairy farming systems increasingly attract policy makers' and scientists' attention. Owing to their limited use of purchased inputs, they can contribute to reducing the environmental impact of agriculture. Furthermore, self-sufficient farming tends to be linked with a search for autonomy in decision-making, i.e., farmers developing their own technical reference framework. Such farming systems can thus also contribute to alternative development pathways of rural territories. In this paper, we analyze how ten intensive mixed crop–dairy farms have progressively evolved toward more self-sufficient and autonomous systems. Through formalizing farmers' transition in action, we identified 34 tools that the farmers implemented making them reflect on their farming system, shift socio-professional networks, reorganize work routines, and steer the evolution of their production practices. For example, they created temporary pastures in crop rotation, introduced rotational pastures, observed their herds to adjust their feed and keep the animals in good health, and they limited expenditures to manage their cash flow. Which tools were used and when they were used depends on what is meaningful to them at various stages of the transition. Our analysis of transitions in action has three original features: it is centered on the transition as perceived by the actors who experience and manage it; it proposes a long-term conceptualization of the dynamics of farming systems, based on the farmer's initiative and creativity; and it highlights tools implemented by farmers during the transition to self-sufficiency and autonomy.

During the 20th century, American agriculture underwent dramatic changes. At the beginning, farms were more diverse, dependent on animal traction, on-farm inputs and income and, after initial land grants, nearly independent of government policy. However, external issues, such as government policies, mechanization, fossil fuel costs, increased consolidation and vertical integration of markets and increased societal awareness of the environment and concern with farming practices, have substantially altered the structure of agriculture. These external issues are significant drivers of agriculture and we grouped them into social/political, economic, environmental and technological drivers. Previous papers have examined specific effects of these drivers. Our objective is to examine how these drivers interact and influence today's agricultural systems. We developed four categories: (1) Commodity Crop Production, (2) Supply Chain Livestock Production, (3) Organic Production and (4) Extensive Livestock Production, to describe major current agricultural systems. These categories were developed as major and contrasting systems but do not represent all of American agriculture. Although it is not possible to predict the future, interactions among the various drivers will affect these systems differently. By examining multiple scenarios, we conclude the highly specialized systems (Nos. 1 and 2) are highly vulnerable to future changes, and that developing adaptive capacity is critical for dealing with new uncertainty. Sustainable agricultural systems will need balance among various domains to be able to adapt and survive. We suggest that the concept of dynamic-integrated agricultural systems may be the best way to meet this goal because of its ability to consider multiple goals and flexible producer decision-making.

In this research an alternative is proposed for viticulture producers that would allow them to maintain their income and prevent the abandonment of their agricultural activity. The proposed alternative is the production of organic wine with subsequent commercialization in the local market. The suitability of the alternative is measured by the acceptance of the product in local markets. This acceptance was determined through contingent valuation, which relates probability of purchase to willingness to pay (WTP). Since regional differences could exist for product acceptance, the preliminary hypothesis was formulated that the importance of the viticulture sector in the regional economy makes consumers value farm work more highly and pay more for sustainable agricultural practices. Two regions of Spain were taken into consideration because of the different weight of their agricultural activity: Castile-La Mancha and the Community of Valencia. A survey of 800 wine consumers was made (400 from each region) to determine WTP. From the results it was shown on the one hand that organizing organic wine in local markets can be a profitable alternative for wine producers and, on the other hand, consumers from regions where wine production shares a larger proportion of the regional economy are willing to pay more for organic wine.

The use of killed cover crop mulch for weed suppression, soil erosion prevention and many other soil and crop benefits has been demonstrated in organic no-till or zero-till farming systems in eastern US regions and in Canada. Implements have been developed to make this system possible by terminating cover crops mechanically with little, if any, soil disturbance. Ongoing research in the US northern Great Plains is being conducted to identify cover crop species and termination methods for use in organic zero-till (OZ) systems that are adapted to the crop rotations and climate of this semi-arid region. Current termination strategies must be improved so that cover crop species are killed consistently and early enough in the growing season so that subsequent cash crops can be grown and harvested successfully. Delaying termination until advanced growth stages improves killing efficacy of cover crops and may provide weed-suppressive mulch for the remainder of the growing season, allowing no-till spring seeding of cash crops during the next growing season. Excessive water use by cover crops, inability of legume cover crops to supply adequate amounts of N for subsequent cash crops and failure of cover crops to suppress perennial weeds are additional obstacles that must be overcome before the use of killed cover crop mulch can be promoted as a weed control alternative to tillage in the US northern Great Plains. Use of vegetative mulch produced by killed cover crops will not be a panacea for the weed control challenges faced by organic growers, but rather one tool along with crop rotation, novel grazing strategies, the judicious use of high-residue cultivation equipment, such as the blade plow, and the use of approved herbicides with systemic activity in some instances, to provide organic farmers with new opportunities to incorporate OZ practices into their cropping systems. Emerging crop rotation designs for organic no-till systems may provide for more efficient use of nutrient and water resources, opportunities for livestock grazing before, during or after cash crop phases and improved integrated weed management strategies on organic farms.

The success of fair trade labels for food products imported from the Global South has attracted interest from producers and activists in the Global North. Efforts are under way to develop domestic versions of fair trade in regions that include the United States, Canada and the United Kingdom. Fair trade, which is based on price premiums to support agricultural producers and workers in the Global South, has enjoyed tremendous sales growth in the past decade. Will consumers also pay a price premium to improve the conditions of those engaged in agriculture closer to home? To address this question, consumer willingness to pay for food embodying a living wage and safe working conditions for farmworkers was assessed with a national survey in the United States. The question format was a discrete choice (yes/no) response to one of four randomly selected price premiums, as applied to a hypothetical example of a pint of strawberries. Multilevel regression models indicated that respondents were willing to pay a median of 68% more for these criteria, with frequent organic consumers and those who consider the environment when making purchases most willing to pay higher amounts. Although the results should be interpreted with caution, given the well-known gap between expressed attitudes and actual behaviors, we conclude that there is a strong potential market opportunity for domestic fair trade.

Global poverty and food insecurity continue to remain critical issues, especially in rural areas. Developing and fostering agricultural systems that not only require low to moderate amounts of economic capital and few external inputs but also maintain and enhance the resource base of production are key features of sustainable agricultural development. Sustainable agricultural development, including diversifying smallholder production to include livestock, is a pragmatic approach to address both rural poverty and food insecurity. Livestock play important roles in the lives of humans as converters, recyclers and banks of nutrients. Smallholders raise a diversity of livestock species and often raise multiple species simultaneously. High fecundity, diet flexibility and adaptability to a wide range of housing and management approaches are critical traits of livestock species well suited for producing meat for home consumption and marketing in the context of rural smallholders. Swine (Sus scrofa) and chicken (Gallus domesticus) meet many of these criteria and are well known livestock species. This paper examines the potential for a less common species of livestock, guinea pig (Cavia porcellus) to enhance food security and increase household income of rural smallholders. Although cultural acceptance of guinea pig as a source of nutrition and income is less ubiquitous than that of swine, chicken and other species, the biological, ecological and economic advantages of guinea pig deserve further examination by those working to alleviate global poverty and food insecurity.

Sweet pepper plants were grown in a greenhouse under three different cultivation methods (organic, integrated and conventional farming). During the crop cycle, plant growth and especially yield and fruit quality parameters were monitored to determine the effects of the different fertilization strategies. Plant fresh weight and total leaf fresh weight were progressively reduced, relative to the other treatments, in the organic treatment compared with the conventional, and at the end of the crop cycle these parameters were reduced by 32.6 and 35% respectively. This reduction in growth was directly correlated with plant nitrate concentration and, at the end of the study, nitrate concentration was reduced almost completely in the organic treatment. Despite the important effect on growth, no significant differences in total marketable yield were observed between conventional and organic farming, although integrated farming showed the highest yield in the extra and first class fruit categories. Organic farming increased antioxidant activity but reduced both chlorophylls and β-carotene. Fruit firmness, pericarp thickness, pH and total soluble solids content showed higher values with the organic method, but these differences were not significant with respect to the conventional method. Our results show the advantages of the organic fertilization, from both environmental and economic perspectives, if proper dosage is added to the crop and the demonstrated buffer capacity of these plants, with respect to maintaining yield under nutrient depletion at later stages of development, is taken into account.

Recent volatility in supplies and prices of natural gas and synthetic nitrogen (N) fertilizer suggests a need to develop and refine alternative strategies for supplying N to corn. In this study, conducted in north-eastern Iowa, we examined the use of red clover and alfalfa green manures as means of supplying N to a succeeding corn crop. Red clover intercropped with oat produced significantly more biomass and contained more N than alfalfa intercropped with oat. Tilling green manures in the fall or delaying tillage until the following spring did not have a consistent effect on green manure N content. Without N fertilizer, corn grain yield following oat–red clover and oat–alfalfa was 25–63% greater than following oat grown alone, but at the highest fertilizer rate (202 kg N ha−1), there was no difference in corn yield between oat–legume and oat-alone treatments. These patterns support the premise that legume green manure effects on corn yield were N-related. Red clover green manure had an N fertilizer replacement value for corn of 87–184 kg N ha−1; alfalfa supplied corn with the equivalent of 70–121 kg N ha−1. At a fossil energy cost for N fertilizer of 57 MJ kg−1 N, reducing synthetic N fertilizer applications to corn by 70–184 kg N ha−1 would represent a fossil fuel savings of 3990–10,488 MJ ha−1, equivalent to the energy content of 104–274 m3 of natural gas. These types of savings are likely to become increasingly important as fossil energy supplies become scarcer and fertilizer prices rise.

Agricultural systems produce both detrimental and beneficial effects on soil quality (SQ). We compared soil physical properties of long-term conventional (CON) and alternative (ALT) cropping systems near Akron, Colorado (CO); Brookings, South Dakota (SD); Bushland, Texas (TX); Fargo, North Dakota (ND); Mandan (ND); Mead, Nebraska (NE); Sidney, Montana (MT); and Swift Current, Saskatchewan (SK), Canada. Objectives were to quantify the changes in soil physical attributes in cropping systems and assess the potential of individual soil attributes as sensitive indicators of change in SQ. Soil samples were collected three times per year from each treatment at each site for one rotation cycle (4 years at Brookings and Mead). Water infiltration rates were measured. Soil bulk density (BD) and gravimetric water were measured at 0–7.5, 7.5–15, and 15–30 cm depth increments and water-filled pore space ratio (WFPS) was calculated. At six locations, a rotary sieve was used to separate soil (top 5 cm) into six aggregate size groups and calculate mean weight diameter (MWD) of dry aggregates. Under the CON system at Brookings, dry aggregates (>19 mm) abraded into the smallest size class (<0.4 mm) on sieving. In contrast, the large aggregates from the ALT system abraded into size classes between 2 and 6 mm. Dry aggregate size distribution (DASD) shows promise as an indicator of SQ related to susceptibility of soil to wind erosion. Aggregates from CON were least stable in water. Soil C was greater under ALT than CON for both Brookings and Mead. At other locations, MWD of aggregates under continuous crop or no tillage (ALT systems) was greater than MWD under CON. There was no crop system effect on water infiltration rates for locations having the same tillage within cropping system. Tillage resulted in increased, decreased, or unchanged near-surface BD. Because there was significant temporal variation in water infiltration, MWD, and BD, conclusions based on a single point-in-time observation should be avoided. Elevated WFPS at Fargo, Brookings, and Mead may have resulted in anaerobic soil conditions during a portion of the year. Repeated measurements of WFPS or DASD revealed important temporal characteristics of SQ that could be used to judge soil condition as affected by management.

There are many economic, social and environmental reasons to reduce the occurrence of food that is wasted. As communities consider options for managing their food waste streams, an understanding of the volume, composition and variability of these streams is needed to inform the decision-making process and potentially justify the capital investments needed for separation and treatment operations. This more detailed inventory also allows for the estimation of embodied resources in food that is wasted, demonstrated herein for greenhouse gas emissions (GHGs). Pre- and post-consumer food waste was collected from four all-you-care-to-eat Campus Dining Services (CDS) facilities at the University of Missouri, Columbia over 3 months in 2014. During the study period approximately 246.3 metric tons (t) of food reached the retail level at the four facilities. 232.4 t of this food was served and 13.9 t of it (10.1 t of edible and 3.8 t of inedible), was lost as pre-consumer waste. Over the same time period, an estimated 26.4 t of post-consumer food waste was generated at these facilities, 21.2 t of the waste edible and 5.3 t of it inedible. Overall, 5.6% of food reaching the retail level was lost at the pre-consumer stage and 10.7% was lost at the post-consumer stage. Out of the food categories examined, ‘fruits and vegetables’ constituted the largest source of food waste by weight, with grains as the second largest source of food waste by weight. GHGs embodied in edible food waste were calculated. Over the study period an estimated 11.1 t CO2e (100-yr) were embodied in the pre-consumer food waste and 56.1 t were embodied in post-consumer food waste for a total of 67.2 t. The ‘meat and protein’ category represents the largest embodiment of GHG emissions in both the pre- and post-consumer categories despite ranking fourth in total weight. Beef represents the largest contribution to post-consumer GHG emissions embodied in food waste with an estimated 34.1 t CO2e. This distinction between the greatest sources of food waste by weight and the greatest sources of GHG emissions is relevant when considering alternative management options for food waste.

Research has shown that agricultural professionals are one of the major influences on farmer adoption of agricultural innovations. Genetic engineering and organic farming represent two vastly different innovations in agriculture, and both assert to have important sustainability outcomes. This paper presents the views from a telephone survey of agricultural scientists, extension officers and academics in Australia (n=185) on the barriers to further adoption of organic farming and agricultural genetic engineering, as well as exploring where they obtain their information about the two innovations. Many professionals believe that market issues (in terms of small market size and the extent that consumers are willing to pay premiums) will limit the size of farmer adoption of organics in Australia, while on-farm issues (in terms of production difficulties and pest and disease problems) are named as the second largest barrier to further adoption. On the other hand, professionals from the targeted sample, who were more knowledgeable about organic farming, named information needs and lack of government support as the major barrier facing further diffusion of organic farming. In contrast, public attitudes and negative media portrayal are named as the largest barrier facing further adoption of genetic engineering in Australia. The uncertainty surrounding the research into genetic engineering (and the lack of long-term research) is believed to be the second largest barrier facing further diffusion of genetic engineering while market problems are seen as the third largest barrier.

This study evaluated the most significant physical, chemical and biological soil properties from a group of organic olive farms located in a typical olive-growing area of Andalusia, Spain, after 5 or more years since the shift from conventional to organic farming, and compared soils with those in nearby undisturbed (U) natural areas. Two soil management systems implemented in these organic olive farms to control weeds, tillage (T), characterized by non-inverting-shallow tillage in spring, and mechanical mowing (M), were compared and evaluated against the U areas. Organic olive orchards showed similar productivity (average fruit yield of 3130 kg ha−1 yr−1) as the conventional, rain-fed olive groves in the same area, with no significant differences due to soil management systems. Soil properties in the olive orchards (i.e. texture, pH, organic carbon (C), organic nitrogen (N), C:N ratio, cation exchange capacity (CEC) and exchangeable potassium) were in the suitable range for olive farming in both soil managements, although organic C and N, saturated hydraulic conductivity and available water-holding capacity (AWC) of the soil were lower than in the U areas. A principal component analysis (PCA) for soil properties in topsoil (0–10 cm depth) distinguished the T from M olive orchards and U areas, and determined organic C and N as the most significant soil properties to characterize them. Average values of soil organic carbon (SOC) stocks for the surface layer (0–10 cm depth) were 18.6, 59.3 and 67.8 Mg ha−1, for T and M soil management systems and U areas, respectively. This indicates that the sustainability of organic olive orchards could be significantly improved by shifting to M soil management to decrease soil erosion and depletion of SOC.

According to the United States Census, California is the most urban state in the nation. Although there are many outstanding examples of urban farms in California, in general, urban agriculture (UA) has been slower to gain momentum here than in some other states with large urban populations. Over the past several years, urban agriculture's popularity in California has begun to escalate, with strong emerging interest in San Francisco, San Jose, Oakland, San Diego, Los Angeles and other metropolitan communities. One challenge for urban farmers and municipal decision makers engaged with UA in California has been limited availability of relevant information and technical assistance. A new project team at the University of California Cooperative Extension, part of the Division of Agriculture and Natural Resources (UC ANR) is working to develop web-based educational resources that will be grounded in a needs assessment that is currently underway. The needs assessment includes a literature review, an internal survey of UC ANR personnel, and community clientele interviews. This paper will report on preliminary findings and analyses of the needs assessment, particularly how UC ANR personnel are engaged with UA, and what tools they think would best serve urban farmers. We suggest implications for those involved with UA, such as personnel of land-grant universities, local governments and non-profits seeking to address the needs of urban farmers in an environment of constrained resources.

Weeds are a major obstacle to successful crop production in organic farming. Producers may be able to reduce inputs for weed management by designing rotations to disrupt population dynamics of weeds. Population-based management in conventional farming has reduced herbicide use by 50% because weed density declines in cropland across time. In this paper, we suggest a 9-year rotation comprised of perennial forages and annual crops that will disrupt weed population growth and reduce weed density in organic systems. Lower weed density will also improve effectiveness of weed control tactics used for an individual crop. The rotation includes 3-year intervals of no-till, which will improve both weed population management and soil health. Even though this rotation has not been field tested, it provides an example of designing rotations to disrupt population dynamics of weeds. Also, producers may gain additional benefits of higher crop yield and increased nitrogen supply with this rotation design.