The goal of this study is to perform a comparative analysis of agroecological and conventional small coffee farms. We investigated 15 coffee farms in the East region of Minas Gerais, a Brazilian rural region, based on coffee production using a multicriteria analysis with economic, social and environmental factors. The results suggest that agroecological farms perform better than conventional farms in terms of sustainability, reduce labor intensity and improve income stability and the environmental impact, such as agro-biodiversity and forest cover. In particular, the results reveal that agroecological farms, though they have lower levels of coffee productivity than conventional farms, perform better in terms of income stabilization. This result depends on product diversification (such as agri-food products, vegetables or fruits) for local markets, which reduces farmer risks associated with coffee price volatility, improving both the local economy and local food security. Moreover, agroecological farms rely more on labor than capital. Overall, the results of this study reveal that agroecological systems support the socio-economic sustainability of the rural areas under study and suggest the potential of agroecology to boost sustainable development in the East Region of Minas Gerais. In short, the spread of agroecological systems could improve local employment conditions, reducing migration toward large cities and shanty towns in other parts of Brazil. Hence, agroecology systems can represent the main alternative to conventional production systems to improve the well-being and wealth of rural populations in developing countries. The analysis presented in this study is based on a specific case study, but the rural area under study has many similarities with other areas in Latin America regarding all aspects of economic, social and environmental sustainability. Finally, some agricultural policy implications are discussed.

Agriculture is a large source of greenhouse gas (GHG) emissions but changing management practices to those more beneficial to the environment could help mitigate climate change as long as they are economically and environmentally viable. This study examines the environmental (public) and economic (private) effects of adopting ten different beneficial management practices on a representative corn farm in Ontario, Canada. The study integrates changes in GHG emissions in carbon equivalents (CO2e) and changes in profit from changes in costs and revenues in two dimensions to reveal the scope and scale of different kinds of practices. 4R nitrogen management practices are smaller in scale compared to cropping practices and, therefore, have smaller potential costs and benefits. Land use changes, from practices including biomass, afforestation, crop rotation and cover cropping, have larger impacts on soil sequestration and carbon-equivalent GHG reduction, but with significantly greater costs. Seven practices were found to, at least partially, be economically and environmentally beneficial. The adoption of no-till and N-rate reduction is firmly positive, whereas the production of biomass has the largest potential economic and environmental gains. Crop rotation and diversification and cover cropping can be mutually beneficial, as can changing N-application practices. The use of inhibitors may be economically beneficial if yield gains outweigh purchase costs.

Since 1985, land retirement has been the primary approach used by the federal government for environmental protection of agricultural landscapes, but increasingly it is being supplemented by conservation initiatives on working lands. This shift logically supports agroforestry and other multifunctional approaches as a means to combine production and conservation. However, such approaches can be complex and difficult to design, contributing to the limited adoption in the USA. To understand and improve the integration of multifunctional landscapes into conservation programs, we worked with 15 landowners in a collaborative design process to build unique conservation plans utilizing agroforestry. We interviewed participants before and after the design process to examine the utility of a personalized design process, applicability of agroforestry to conservation programs and pathways to improve conservation policy. We found that landowners strongly preferred working in person for the design process, and being presented a comparison of alternative designs, rather than a single option, especially for novel systems. Agroforestry was seen as a viable method of generating conservation benefits while providing value to the landowners, each of whom stated they were more inclined to adopt such practices irrespective of financial assistance to do so. For conservation programs, landowners suggested reducing their complexity, inflexibility and impersonal nature to improve the integration of multifunctional practices that appeal directly to the practitioner's needs and preferences. These findings are valuable for conservation policy because they complement previous research theory suggesting the value of working collaboratively with landowners in the design of multifunctional landscapes. Personalized solutions that are developed based on the unique characteristics of the local landscape and the preferences of the individual landowner may be retained beyond a specified payment period, rather than being converted back into annual crop production.

Soil suppressiveness which is the natural ability of soil to support optimal plant growth and health is the resultant of multiple soil microbial components; which implies many difficulties when estimating this soil condition. Microbial benefits for plant health from repeated digestate applications were assessed in three experimental sites surrounding anaerobic biogas plants in an intensively cultivated area of northern Italy. A 2-yr trial was performed in 2017 and 2018 by performing an in-pot plant growth assay, using soil samples taken from two fields for each experimental site, of which one had been repeatedly amended with anaerobic biogas digestate and the other had not. These fields were similar in management and crop sequences (maize was the recurrent crop) for the last 10 yr. Plant growth response in the bioassay was expressed as plant biomass production, root colonization frequency by soil-borne fungi were estimated to evaluate the impact of soil-borne pathogens on plant growth, abundance of Pseudomonas and actinomycetes populations in rhizosphere were estimated as beneficial soil microbial indicators. Repeated soil amendment with digestate increased significantly soil capacity to support plant biomass production as compared to unamended control in both the years. Findings supported evidence that this increase was principally attributable to a higher natural ability of digestate-amended soils to reduce root infection by saprophytic soil-borne pathogens whose inoculum was increased by the recurrent maize cultivation. Pseudomonas and actinomycetes were always more abundant in digestate-amended soils suggesting that both these large bacterial groups were involved in the increase of their natural capacity to control soil-borne pathogens (soil suppressiveness).

Conventional cotton production has been associated with the extensive use of agricultural chemicals, leading to environmental and health problems, decreased effectiveness of pesticides and higher costs of production. Organic bans the use of most pesticides while providing premiums for growers, and therefore may be a beneficial alternative for growers. Unfortunately, there has been a paucity of research examining the specific practices used by organic cotton growers and the environmental aspects of those practices. This study surveyed organic cotton producers and processors to document specific approaches and techniques used in organic cotton production and processing, the environmental impacts of those techniques and challenges facing organic cotton growers. We discuss the environmental impacts of organic management techniques and methods for conserving water and reducing dependence on irrigation. We also highlight the challenges to organic production identified in the survey, including management for weeds, insects and diseases, genetic contamination of organic crops from genetically modified cotton, organic seed availability, climate change, chemical drift and marketing of organic cotton. Finally, we suggest that investing in research to produce higher-yielding organic varieties, improved methods for organic weed management, and supporting carbon-sequestering practices will improve conversion to organic production.

The sustainability of an agricultural field is largely influenced by crop growth habit and management practices such as tillage. Both strongly interact to shape ecosystem properties such as the fluxes and stocks of carbon and nitrogen. Recently, researchers have worked to develop perennial grain crops in order to enhance key ecosystem processes, such as carbon cycling and nitrogen fixation, with the use of perennial crops rather than traditionally used annual crops. In this study, we aimed to understand how soil disturbance combined with vegetation type [annual monoculture crops vs. perennial monocultures (intermediate wheatgrass (IWG)) vs restored native vegetation (RNV)] influenced the soil carbon and nitrogen dynamics. We collected soil samples at two depths (0–15 cm and 15–30 cm) from each vegetation treatment and incubated the soils in the laboratory for 120 days to determine the efflux of carbon and also analyzed the mineralization of both carbon and nitrogen. The results demonstrated the soils from the IWG had the greatest carbon flux, as well as carbon and nitrogen storage (annual monoculture < RNV < IWG). The differences in carbon flux, carbon and nitrogen storage from the IWG to the annual monoculture were 27, 40, 20%, respectively, while the IWG to the RNV was 11, 20, 10%. Shallow soil samples exhibited greater differences in all C and N comparisons between treatments compared to deeper soil samples. Taken together, our findings indicate that crop vegetation type and soil depth strongly influence carbon and nitrogen dynamics.

Double-cropping winter rye cover crops (CC) with soybean in the North Central US could help with the global effort to sustainably intensify agriculture. Studies addressing the management of these systems are limited. Therefore, a field study was conducted from 2017 to 2019 in Central Iowa, US to evaluate winter rye CC biomass production, aboveground N accumulation, estimated economics, estimated within-field energy balance and estimated greenhouse gas (GHG) emissions under three N application rates (0, 60, 120 kg N ha−1) and three planting methods (pre- and post-harvest broadcast and post-harvest drilling). Averaged over N rates, all planting methods resulted in >5.0 Mg ha−1 year−1 rye aboveground biomass dry matter. Averaged over the 2-year study and compared with unfertilized treatments, applying 60 kg N ha−1 produced 1.1 Mg ha−1 more aboveground biomass (6.1 vs 5.0 Mg ha−1), accumulated 30 kg ha−1 more N in aboveground biomass (88 vs 58 kg N ha−1), and led to 20 GJ ha−1 more net energy. Biomass production was not significantly higher with 120 kg N ha−1 compared with the 60 kg N ha−1 rate. Even when accounting for an estimated 0.75 Mg ha−1 of above ground rye biomass left in the field after harvesting, more N was removed than applied at the 60 kg N ha−1 rate. The minimum rye prices over the 2-year study needed for double-cropping winter rye CC to be profitable (breakeven prices) averaged $117 and $104 Mg−1 for the 0 and 60 kg N ha−1 rates, which factors in estimated soybean yield reductions in 2019 compared with local averages but not off-site transportation. GHG emissions were estimated to increase approximately threefold between the unfertilized and 60 kg N ha−1 rates without considering bioenergy offsets. While environmental tradeoffs need further study, results suggest harvesting fertilized rye CC biomass before planting soybean is a promising practice for the North Central US to maximize total crop and net energy production.

The global population is projected to be enormous by the mid-21st century, whereas, most essential crops being sustained by the rain-fed agriculture are threatened by climate change. Therefore, the study investigated the projected near-future effect of rainfall variability on rot incidence and yam production in humid tropical Nigeria. Production data from the Food and Agriculture Organization and the Nigeria National Bureau of Statistics showed the significant increasing trend in the annual yam output. The field survey conducted in 2018 showed that the maximum percentage of rot incidence occurred in July. Climate Research Unit observational rainfall data from 1979 to 2018 showed the nonsignificant trend in the interannual rainfall variability; however, it showed low variability and a significant decreasing trend in the July rainfall. A pathogenicity test on yam samples confirmed rot by fungi, bacteria and nematodes as virulent pathogens, whereas, the nutritional qualities of the rotted yams were indicated. Monthly rainfall and rot incidence showed positive correlation (r = 0.84, significant at 99% from t-test). The positive characteristic impact values indicated that increase (decrease) in the monthly rainfall corresponds to increase (decrease) in the magnitude of monthly percentage rot incidence. Thus, the significantly decreasing rainfall reduced the quantity of rot incidence and consequently increased the annual yam production for the period. Selected CoOrdinated Regional Downscaling EXperiment-Africa models and the ensemble mean showed a good measure of agreement with observational rainfall in the historical experiments. The efficiencies of the bias-corrected outputs in the representative concentration pathway (RCP) 4.5 and 8.5 indicated improved ‘reasonable’ performances. Bias-corrected projections of the July rainfall showed an increasing trend in both the RCPs, which indicate a potential increase in rot incidence and the consequent decline in annual yam production. The findings are imperative in sustaining the global food supply.

Two solid state anaerobic digesters (SSADs), 15 L each, were set up for co-digestion of switchgrass with primary digestate of a liquid anaerobic digester (LAD) and the recirculating leachate. Both the LAD and two SSADs were operated at 50°C. The results showed that the bioreactors were not started up stably until day 16 and day 47 for reactors A and B, respectively. The supplement of LAD digestate or injection of sodium hydroxide (NaOH) into the recirculating leachate readily reinitiated the biogas production to normal daily high rates of the two individual SSADs, one on day 16 and the other on day 47. In contrast to reactor A, there was a longer lag phase for bioreactor B, however, it showed 46.2% [77.9 vs 53.3 L kg−1 volatile solid (VS)] more cumulative biogas yields, and higher reduction rate of total solid, VS, cellulose and hemicellulose of 29.5, 31, 40.6 and 15%, respectively, which was likely due to optimized pH and NaOH pretreated switchgrass during start-up period. Methane contents of biogas increased gradually and stabilized at 50% for both reactors, indicating a normal operation of anaerobic digestion lasted for at least 100 days. The determined parameters of digested residues met China organic fertilizer standard (NY 525-2012) except for high moisture and low total nutrient contents. Therefore, the product of SSAD has the potential value of organic fertilizer. It is concluded that the LAD digestate can be reused as inoculums by co-digestion with agricultural residues for biogas and organic fertilizer production in SSAD.

This study examined energy, greenhouse gas emission and ecological footprint analysis (EFA) of chickpea and lentil cultivation with different mechanization production systems. In lentil production, except for tillage operations, other operations are performed manually and the remaining straw is burned in the field; while in chickpea production, most of the agricultural operations are mechanized and residues are collected, baled and transferred to the warehouse for animal feed. In this paper, for the first time, some of the sustainability indicators are investigated and compared in two different legume production systems. Energy productivity and net energy for chickpea and lentil production were calculated at 0.036, 0.161 and 2373 and 5900 MJ per hectare, respectively. The CO2 emission and ecological carbon footprint were 173 kg CO2−eq and 0.15 global hectare for lentil and 484 and 0.87 for chickpea production. Totally, due to excessive consumption of diesel fuel and lack of proper management, the social cost of emission from straw baling in chickpea production (27.65 dollars per hectare) was higher than burning straw in lentil production (8.77). Multi-objective genetic algorithm results showed the potential of minimizing diesel fuel and fertilizer consumption and no chemical for chickpea production. Overall audition results of two different production systems revealed that traditional lentil production is more sustainable. Therefore, implementations of modern agricultural practices alone are not enough to achieve sustainability in agricultural production systems.

With the adverse effects of climate change becoming more prominent, more effective strategies for reducing the increase in atmospheric CO2 levels are required for mitigating further climate change. Increasing use of renewable energy by farmers motivated to practice agroforestry is one natural solution for reducing those climate change impacts. Unfortunately, climate change mitigation through agroforestry has been inhibited by a lack of scientific validation. In this paper, we ascertain factors that motivate African cocoa farmers to use agroforestry practices for enhancing food production as well as for mitigating climate change. We analyzed data collected from 120 farmers from the Oyo state of Nigeria through descriptive and regression analysis statistical tools. We found that access to information (β = 0.23, t = 2.18) and extension service (β = 0.23, t = 2.27) was associated with greater willingness of farmers to participate in agroforestry whereas negative attitudes (β = −0.29, t = −3.21) were associated with a lower involvement of cocoa farmers in agroforestry practices. We conclude that effective climate change mitigation programs need to do more to motivate farmers to adopt agroforestry practices by increasing their understanding of the benefits to be derived from carbon markets and by providing them with the necessary tools for employing these practices for climate change mitigation and more sustainable food production.

Farmers, particularly small farmers, are on the frontlines of climate change. In Oregon's Southern Willamette Valley, a needs assessment was conducted of small farmers in 2017, where questions related to climate change risks, attitudes toward adaptation and climate beliefs were assessed. Out of all the respondents (n = 123), the majority (70%) believe that climate change is occurring, and is caused mostly by human activities. The majority (58%) also strongly agree with the statement that they will have to change practices to cope with increasing climate variability in order to ensure the long-term success of their operation. Another 52% of these respondents indicated that they have already taken action to respond to climate change on their farms. However, only 32% of respondents agreed with the statement that they have the knowledge and skills to deal with weather-related threats to their operation. While this work is preliminary and not comprehensive, our findings suggest that these small farmers are concerned about climate change, readily accept the science as compared to other farmer groups in the USA, and are looking for additional tools and resource to increase their confidence in responding to the challenges they will face as a consequence of climate change.

This paper presents a novel approach to multi-criteria sustainability performance assessment of horticultural crops. The crops are ranked by the decision-making method ELECTRE IV with environmental, energy and technological criteria. In total eight indicators are taken into consideration and calculated based on primary data collected from over 260 farms in northern Iran. Additionally, Data Envelopment Analysis is used to calculate the technical efficiency and potential for energy saving by different management of the production units. The novel contribution of this study is the comparison of several horticultural products (oranges, kiwis, persimmons and tangerines), when most of the previous studies have focused on one product. Moreover, novel calculations of the carbon footprint are presented for oranges, tangerines and persimmons. This paper also includes the first study on the environmental impact of persimmon fruit's production. The obtained results show that energy efficiency for orange, tangerine, kiwi and persimmon products: 1.1, 0.84, 0.53 and 1.22, respectively. In each hectare of kiwi orchards, the amount of CO2 emissions of 1219 kg and the ecological footprint of 3.21 hectares have been calculated, which is statistically significant compared to orange, tangerine and persimmon. The chemical and fuel inputs have the greatest potential for reducing energy consumption in the studied products. Results of ELECTRE IV showed that kiwi is the most sustainable selection for the studied region followed by orange, persimmon and tangerine, respectively. Kiwi has also relatively low technical efficiency. This means that this product has the greatest potential for a reduction of energy consumption, while maintaining the same amount of crop. It is recommended to include the development of kiwi orchards in the policies of Guilan, but with more careful management of the production inputs.

Kernza® intermediate wheatgrass (Thinopyrum intermedium) is a novel perennial grain and forage crop with the potential to provide multiple ecosystem services, which recently became commercially available to farmers in the USA. The viability and further expansion of this promising crop require understanding how it may fit the needs of farmers’ livelihoods and the structure of their farming systems. However, no prior research has studied the perceptions and experiences of Kernza growers. The goals of this research were to understand why farmers grow Kernza, how Kernza fits into their systems and identify challenges for future research. We conducted in-depth interviews with ten growers in the North Central USA during the summer of 2017, who accounted for a third of the Kernza farmers in the USA at the time. All farmers had a positive attitude toward experimentation and trying new practices, and they were interested in Kernza for its simultaneous ecological and economic benefits. Kernza was marginal in terms of area, quality of fields and resources allocated in the farm systems, which also meant that farmers maintained low costs and risks. Growers utilized and valued Kernza as a dual-use crop (grain and forage), sometimes not harvesting grain but almost always grazing or harvesting hay and straw for bedding. Weeds were perceived as a challenge in some cases, but Kernza was valued as a highly weed-suppressive crop in others. Farmers requested information on optimal establishment practices, assessment of forage nutritive value, how to maintain grain yields over years, weed management, markets and economic assessment of Kernza systems. These results agree with other cases on sustainable practices adoption showing that engaging farmers in the research process from the beginning, identifying knowledge gaps and testing management alternatives are critical for the success and expansion of novel agricultural technologies.

Much of the global population lacks access to basic public sanitation, energy and fertilizers. Micro-scale anaerobic digestion presents an opportunity for low-cost decentralized waste management that creates valuable co-products of renewable energy and organic fertilizer. However, field-based assessments of system performance and clearly articulated guidelines for digestate management and field application are needed. Feedstocks and effluent from seven digesters in Kampala, Uganda were monitored for standard wastewater and fertilizer metrics including indicator organisms (Escherichia coli and fecal coliform), chemical oxygen demand (COD), biological oxygen demand (BOD5), total Kjeldahl nitrogen (TKN), total phosphorous (TP), heavy metals, pH, temperature and total solids (TS) over 2 yr. Results reveal that digester effluent does not meet standards for wastewater discharge or international safety standards for field application. Data indicate that digestate could be a suitable source of fertilizer (TKN = 1467 mg L−1, TP = 214 mg L−1) but poses issues for water quality if not managed properly (TS = 26,091 mg L−1, COD = 3471 mg L−1 and BOD5 = 246 mg L−1). While effluent from the digester contained pathogen indicator organisms (fecal coliform = 8.13 × 105 CFU/100 ml, E. coli = 3.27 × 105 CFU/100 ml), they were lower than the influent concentrations, and lower than reported concentrations in drainage canals. All digestate samples contained little to no heavy metals suggesting effective source separation. Data suggest that micro-scale biogas systems have potential to improve waste handling and meet standards associated with fertilizer application with proper post-digestion treatment.