Granular temporal and spatial scale observations of conservation practices are essential for identifying changes in the production systems that improve soil health and water quality and inform long-term agricultural research and adaptive policy development. In this study, we demonstrate an innovative use of farmer practice survey data and what can be uniquely known from a detailed survey that targets specific farm groups with a regional focus over multiple consecutive years. Using three years of survey data (n = 3914 respondents), we describe prevailing crop rotation, tillage, and cover crop practice use in four Midwestern US states. Like national metrics, the results confirm dominant practices across the landscape, including corn-soybean rotation, little use of continuous no-till, and the limited use of cover crops. Our detailed regional survey further reveals differences by state for no-till and cover crop adoption rates that were not captured in federal datasets. For example, 66% of sampled acreage in the Midwest has corn and soybean rotation, with Illinois having the highest rate (72%) and Michigan the lowest (41%). In 2018, 20% of the corn acreage and 38% of the soybean acreage were in no-till, and 13% of the corn acres and 9% of the soybean acres were planted with a cover crop. Cover crop adoption rates fluctuate from year to year. Results demonstrate the value of a farmer survey at state scales over multiple years in complementing federal statistics and monitoring state and yearly differences in practice adoption. Agricultural policies and industry heavily depend on accurate and timely information that reflects spatial and temporal dynamics. We recommend building an agricultural information exchange and workforce that integrates diverse data sources with complementary strengths to provide a greater understanding of agricultural management practices that provide baseline data for prevailing practices.

There have been no systematic experiments conducted in Nevada's water-limited environment that examined the simultaneous benefits of soil health and feed value derived from cool-season cover cropping systems. The objective of this study was to determine the influence of different annual cool-season cover crop systems on above and belowground biomass production, plant tissue carbon and nitrogen, forage nutritive value (crude protein, acid, and neutral detergent fiber), relative feed value (RFV), and short-term soil health indicators under irrigation in a semi-arid environment. Treatments (cover crop systems) were a fallow (no cover crop), five monocultures of rye (Secale cereale L.), winter lentil (Lens culinaris Medik.), arrowleaf clover (Trifolium vesiculosum Savi), white sweetclover (Melilotus alba), forage kale (Brassica oleracea L.), and two three-species mixtures in 50-25-25 seeding ratios (CCM 1: rye, winter lentil, arrowleaf clover; CCM 2: rye, white sweetclover, forage kale). Cover crop systems were arranged in an RCBD with three replications. Plots were fall seeded in Reno, NV early October of each year (2020 and 2021) and terminated at the end of July of 2021 and 2022, respectively. Averaged across years, aboveground biomass production was lowest for the monoculture of winter lentil (4104 kg DM ha−1; SE = 1551) compared to all other cover crop systems (average = 7593 kg DM ha−1; SE = 1551). Biomass carbon produced was lowest for winter lentil (1717 kg ha−1; SE = 675) relative to all other cover crop systems (average = 3227 kg ha−1; SE = 675). The CCM 1 system had a greater C/N ratio (36.3) than CCM 2 and the monocultures of winter lentil, arrowleaf clover, and white sweetclover (average = 24.9). Belowground biomass did not differ among cover crop systems (average = 3161 kg DM ha−1; SE = 962). Crude protein concentration was similar among cover crop systems but the RFV was greatest for forage kale (RFV = 165; SE = 4.0) among all cover crop systems. Soil total N and organic carbon concentration did not differ among cover crop systems but soil K concentration was greatest under fallow (428 mg kg−1 soil; SE = 26) relative to all other systems (average = 345.6 mg kg−1 soil; SE = 26). Soil microbial community biomass was not altered by cover crop system or its interaction with year. While the short-term impact of the cover crop systems on soil health indicators was minimal relative to the fallow system, the overall results suggested that there is potential to integrate cover crops in Nevada's semi-arid environment under irrigation.

Crops emit a variety of volatile organic compounds (VOCs) that serve as attractants or repellents for pests and their natural enemies. Crop rotations, off-farm chemical inputs, and mechanical and cultural tactics – collectively called cropping systems – alter soil nutrients, moisture content, and microbial communities, all of which have the potential to alter crop VOC emissions. Soil legacy effects of diversified cropping systems have been shown to enhance crop VOC emissions in greenhouse studies, but how they influence emissions under field conditions remains virtually unknown. To determine the effect of cropping systems on plant VOC emissions in the field, air samples were collected from the headspace of wheat (Triticum aestivum L. Judee) grown in simplified wheat-fallow rotations or diversified wheat-cover crop rotations where cover crops were terminated by grazing cattle. Across two growing seasons, wheat grown in rotation with fallow emitted greater amounts of Z-3-hexenyl acetate and β-ocimene, key attractants for wheat stem sawfly (Cephus cinctus Norton), a major pest of wheat. While overall VOC blends were relatively similar among cropping system during the first growing season, emissions varied substantially in the second year of this study where wheat grown in rotation with cover crops emitted substantially greater quantities of volatile compounds characteristic of abiotic stress. Below-average precipitation in the second growing season, in addition to reduced soil water content in cover crop rotations, suggests that cropping system effects on wheat VOCs may have been driven primarily by water availability, a major factor limiting crop growth in dryland agriculture. While the specific mechanisms driving changes in VOC emissions were not explicitly tested, this work shows that agricultural practices applied in one growing season can differentially influence crop VOC emissions in the next through soil legacy effects, illustrating additional avenues through which cropping systems may be leveraged to enhance pest management.

Barley is one of the most consumed cereals, with many different cultivars available worldwide. Like other crops, its yield has been affected by climate change and soil degradation. This work proposes controlled-release protein-based matrices with incorporated zinc to improve barley seed germination and zinc content in the plant. Thus, the main objective of this study was to investigate the use of controlled-release protein-based matrices for massive crops, such as barley. Different barley cultivars of barley were studied: Barke, Golden Promise, Morex, WB-200, WB379, and WB-446. The seeds of each cultivar were also analyzed in order to explain the behavior of plants observed during the growth. To this end, the physico-chemical (FT-IR, Raman spectroscopy, and Zn concentration) and microstructural (SEM) properties of the different seeds were firstly evaluated to establish differences between the studied cultivars. In addition, the use of controlled-release soybean protein-based matrices without zinc (M) or with zinc incorporated (MZ) was evaluated as fertilizers in the different barley cultivars. In this sense, the use of these matrices as a zinc carrier improved seed germination and zinc content in the plants, indicating that the use of matrices improves the amount of zinc assimilated by the crops (up to 30 and 50% with M and MZ, respectively) and allows the proper root growth of all cultivars of barley. In conclusion, this article shows the potential of controlled-release protein-based matrices as substitutes for conventional fertilization.

As climate change and agriculture burden water resources globally, there is a need for more efficient water use including irrigation with recycled water in greenhouses. While research has proven that properly treated recycled water can be safe for use, many growers still express concern. Underlying most studies on growers' perceptions is the assumption that they understand recycled water the same way scholars and policy makers do—as municipally treated wastewater. We question this assumption and explore whether the ways in which growers conceptualize recycled water is associated with the ways they perceive its usability. Our findings reveal that growers define recycled water in four different ways—captured water, treated water, recirculation and in a general sense as ‘reuse’. These definitions do appear to suggest trends in the way recycled water is perceived by growers. While these definitions do not significantly affect growers' willingness to use, other factors such as prior experience using recycled water appear to be significant.

In organic farming the control of perennial weed species, in particular Cirsium arvense, can be a major concern for farmers, especially if there is no regulation through perennial forage production. To test whether the stubble cleaner (SC), an enhanced skim plow (PL), is as effective in the control of C. arvense and other weeds as conventional ploughing and perennial forage production, an organic field experiment was established. Three different tillage/crop rotation systems were compared: an SC system and a PL system, both in a cereal-based crop rotation and an additional PL system in a crop rotation that included a perennial alfalfa–grass mixture (PLALF). In the SC system, tillage was carried out solely with the SC, while in the PL and PLALF systems, ploughing was alternated with chiseling. In the fifth year, each main plot was divided into subplots, and seven different cover crop treatments were integrated into each of the three systems. The effects of the three systems and the cover crop treatments on weed cover and density, weed biomass, and weed diversity in the sixth and seventh year of the experiment are the subjects of this paper. The choice of cover crop species was of minor importance for weed control. The PLALF system was generally more effective in controlling C. arvense than the PL and SC systems. No significant differences between the PL and SC systems regarding the control of C. arvense could be identified in four of five assessments. The SC system had significantly higher total weed density than the PLALF and PL systems in both years. However, the differences in weed emergence between the PL and SC systems diminished until the assessment of weed cover and biomass in the main crops, when no significant differences between these two systems (2012) or no differences at all (2013) could be identified. Species richness was not significantly influenced by the tillage/crop rotation system in both years. Evenness and Shannon–Wiener index were significantly higher in the PLALF and PL systems than in the SC system on most assessment dates in 2012. In 2013 there was no clear trend regarding evenness and Shannon-Wiener index probably due to a hoeing operation.. In conclusion, for weed control, the choice of crop rotation was more important than the choice of tillage method, while for the diversity of the weed community, the choice of tillage method was more important than the crop rotation.

Weed competition, especially within the crop row, limits the productivity and profitability of organic crop production. Abrasive weeding, a mechanical alternative to hand weeding, uses air-propelled grits to control small weed seedlings growing within the crop row. Recent research has demonstrated the successful use of abrasive weeding to reduce weed competition and increase yields in organic maize (Zea mays), tomato (Solanum lycopersicum) and green and red pepper crops (Capsicum annuum), but the profitability of this weed control tactic has not been assessed. Our objective was to determine the profitability of abrasive weeding using empirical yield data from three previously published studies, a range of crop prices and revenues, and a range of costs for wages, grit applicator ownership, tractor use, abrasive grits, and fuel. Results suggest that abrasive weeding was not profitable in organic maize production, and may reduce net income by US$223–3537 ha−1 compared with inter-row cultivation alone for weed control. The cost of abrasive weeding in maize was largely dependent on the cost of abrasive grits and the cost to own a four-row grit applicator (US$736–2105 yr−1). However, abrasive weeding was less expensive than hand weeding, especially as the scale of production increased. Abrasive weeding was profitable in tomato and pepper crops and increased net mean income by US$12,251–33,265 ha−1. However, abrasive weeding was not 100% effective and hand weeding for weed-free conditions was always the most profitable approach to in-row weed management in vegetable crops. The profit potential of the hand-weeded, weed-free treatments demonstrates the importance of weed control in high-value specialty crops–even those grown in plastic mulch film. Despite the profit potential for hand weeding observed here, labor is increasingly difficult to source, retain and afford, and abrasive weeding offers a mechanical alternative with 66% less labor required. Further research is needed to improve the efficacy of abrasive weeding and to reduce the cost of abrasive grits and application.

Invasive species control management involves a large amount of plant material. The present work evaluated the allelopathic potential of the invasive species Ulex europaeus L. (Fabaceae) or ‘Gorse’ and its possible use as a bioherbicide, taking advantage of the extracted plant material after control measures, particularly needed in invaded areas. Specifically, we investigated the efficacy of dried plant material from U. europaeus in the control of the adventitious plants, Lolium multiflorum Lam. and Lolium rigidum Gaud., using the Avena sativa L. crop as a case study. We only used vegetative plant parts because it is essential to avoid the dispersion of U. europaeus with its use, especially in invaded areas. A greenhouse pot experiment was conducted, using activated carbon (AC). The target species (L. multiflorum, L. rigidum and A. sativa) were subjected to a mixture of organic substrate with U. europaeus mulch applied pre-emergence and a subsequent application of aqueous extracts from the mulch. Emergence, height and biomass of the target species were determined. After 2 months, we also tested a possible legacy effect of the substrate on the germination of the target species. We noticed a negative effect of U. europaeus mulch on the emergence of L. rigidum, which can be attributable to the allelopathic compounds released from U. europaeus mulch because the effect was non-significant in presence of AC. Conversely, no effect on L. multiflorum or A. sativa was produced by mulch treatments. Nevertheless, the combination of U. europaeus mulch and its extracts demonstrated a phytotoxic effect on the biomass of the crop species A. sativa, and a fertilizing effect on the weeds L. multiflorum and L. rigidum, which is why this use is discouraged. With our results we cannot recommend the use of U. europaeus as a bioherbicide in oat crops, but this study emphasizes the capability of U. europaeus to structure plant communities through the chemic- and bio-properties of its tissues that modifies the soil environment.

Farmers struggle to combat uncertain climate issues while encountering pressure on conventional farming practices that lead to carbon emissions, water and soil pollution, and other environmental harms. A growing body of literature investigated circular economy and sustainable practices to support environmental-friendly agriculture activities while providing opportunities for farmers to improve their farm income. Therefore, a study synthesizing previous literature while identifying actual policy to boost farmers’ implementation of sustainable agriculture is worthwhile. Using the Systematic Literature Review analysis, this paper aims to identify farmers’ views on climate change adaptation and mitigation, challenges in implementing circular economy and sustainable practices, and policies to support farmers’ transition toward sustainable agriculture in developed and developing countries. We found that (1) farmers’ awareness of climate change, knowledge and skills are prominent for adapting and mitigating climate change in both types of countries, (2) farmland size, risks of income loss, and training and extension services influenced farmers’ adaptation and mitigation strategies for climate change in developing countries, (3) farmers in both types of countries experienced uncertainty in economic profits and legislative issues when adopting sustainable practices, while farmers in developing countries issued significant up-front expenses to acquire technology to adopt sustainable practices, (4) financial access and incentives through policy can be valuable to develop sustainable livelihoods, especially for farm households.

Diverse agricultural management practices are critical for agroecosystem sustainability, and cover crops provide opportunity for varied management and increased biodiversity. Understanding how cover crops fill open ecological niches underneath the trees, interact with weeds, and potentially provide ecosystem services to decrease pest pressure is essential for ecological agricultural management. The goal of this study was to test the weed suppression potential of two cover crop treatments with varied functional diversity compared to standard weed management practices in commercial almond orchards in California. Transect plant surveys were used to evaluate orchard plant communities under a functionally diverse seed mix including grasses, legumes, and brassicas, and a relatively uniform cover crop mix that included only brassica species. Winter annual orchard cover crops reduced bare ground from 39.3% of total land area to 15.9 or 11.4%, depending on treatment. Furthermore, winter cover crops displaced weeds with a negative correlation of 0.74. The presence of cover crops did not consistently affect weed community composition for low-richness weed communities found in California orchards. Diverse cover crop mixes more reliably resulted in increased ground cover across site years compared to uniform cover crop mixes, with coefficients of variation for ground cover at 49.6 and 91.5%, respectively. Cover crops with different levels of functional diversity can contribute to orchard weed management programs at commercial scales. Functional diversity supports cover crop establishment, abundance, and competitiveness across varied agroecological conditions, and cover crop mixes could be designed to address an assortment of orchard management concerns.

The rising demand for local, organic bread wheat (Triticum aestivum L.) in the northeastern USA may be an economic and agronomic opportunity for organic dairy producers. Bread wheat must produce adequate grain yields and crude protein (CP) levels to be profitable as a food crop and must complement the on-farm production of high-quality dairy feed. A field study evaluated bread wheat and perennial forage performance in five 3-year crop sequences all ending in a perennial legume/grass forage. The sequences differed by wheat type (winter or spring) and the crop prior to wheat: (1) corn silage (Zea mays L.), (2) soybean (Glycine max L.) or (3) one-year-old perennial forage. Wheat sequences were compared with a sequence of two years of corn silage followed by a new perennial forage seeding and with a continuous perennial forage control. Winter wheat spike density, wheat aboveground biomass and nitrogen uptake were always greater than spring wheat. Wheat grain yield and CP were strongly affected by wheat type, with winter wheat having greater yield but lower CP than spring wheat. At one site-year, winter wheat CP was 15 g kg−1 higher following perennial forage than following corn. Only spring wheat met the bread flour industry standard for CP. Newly established perennial forage following wheat had higher yields and legume composition in both years, along with higher projected milk yields in one year, than the continuous perennial forage. Three-year net revenue based on off-farm sales were on average US$ 741 ha−1 higher for sequences with winter wheat than those with spring wheat, and were equal to the perennial forage control. Rotations that included wheat would likely be more competitive if straw were sold or used on the farm, or, if topdressing practices or varietal choice were used to increase grain protein levels of winter wheat.

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.

One of the greatest challenges in crop science worldwide is to generate a balance between crop production and environmental preservation. Agroforestry systems present promising strategies for balancing environmental health and crop production. The aim of this study was to evaluate yield components and the juice quality of five sugarcane crop years cultivated in the understory of Aleurites fordii, in two intercropping systems and a monocropping system. A field experiment was conducted from November 2011 to June 2016 in the city of Frederico Westphalen—Rio Grande do Sul, Brazil. Information generated in this study confirms the viability of the cultivation of sugarcane in agroforestry systems, and provides information for farmers which can be used to assist in the planning of more ideal agroforestry arrangements. Agroforestry systems should consider the benefits of both forest and cultivated plant species. In this study, A. fordii trees had greater growth in the intercrop II system; however, this system promoted reductions in sugarcane yield components due to the lowest relative amount of solar radiation intercepted by sugarcane plants. For sugarcane production, the use of an intercropping system with 12 × 12 m2 arrangements should be prioritized, because it promotes greater sugarcane yields when compared with 6 × 6 m2 intercropping systems; however, significant differences were not observed when the system (12 × 12 m2) was compared with the monocropping system for most of the analyzed variables. This study sought to provide new sustainable alternatives for farmers in order to increase the diversification of rural properties and maintain the preservation of existing agroecosystems.

Agriculture plays a central role in providing food security and essential goods globally. Producers must consider and manage risk to ensure that the production system and its associated individuals are capable of enduring unexpected and disruptive events. Analyzing the different types of risk and accompanying uncertainties that growers experience can be essential to better reflect and understand the realities of their circumstances, but these concepts are not always accounted for in the adoption process. Drawing on the importance of risk and uncertainty, this study aims to assess the different types of risk and uncertainties involved in the risk decision-making process of the processed raspberry industry, where plastic mulch is a new production technique. Semi-structured interviews were conducted with participants involved in the use, research, outreach, manufacturing, and distribution of plastic mulch, specifically polyethylene (PE) mulch and soil-biodegradable mulch (BDM). Findings indicate that risk can be present in various forms including production, price, and hidden risks, with production and price risks being the most significant to all participants. When accounting for overall risk, PE mulch was considered riskier to industry representatives but less risky to growers and most research and outreach specialists. BDM was considered risky due to the uncertainties about durability, degradability, and the unknown impacts on the environment if BDM fragments do not degrade readily. The application of PE mulch and/or BDM can be beneficial for the raspberry production systems but will require time for additional research and effort to disseminate information to a wider agricultural audience.

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.

Declining nutrient densities of crops in the past 50–70 years have been attributed to unsound agricultural practices and plant breeding focus on yield rather than quality. Few studies have quantified the soil and nutritional quality of grains in organic and conventional farms and reported results are scarce and inconsistent. The Rodale Institute's Farming Systems Trial (FST) was established in 1981 to quantify the effects of long-term organic and conventional grain cropping systems and tillage practices. A 2014 study to quantify effects on the nutrient density of oat grains was integrated into three systems within the long-term trial: organic manure-based (MNR), organic legume-based (LEG), and conventional synthetic input-based (CNV), split between tilled (T) and no-till (NT) practices. Oat grains with hulls removed were analyzed for minerals (n = 24), vitamins (n = 24), amino acids (n = 24) and proteins (n = 24), while soil samples to a depth of 10 cm were analyzed for elemental minerals, and total carbon (C), nitrogen (N) and sulfur (S). Organic systems increased six out ten soil minerals whose concentrations were influenced by cropping systems: aluminum (Al), iron (Fe), chromium (Cr), calcium (Ca), barium (B) and strontium (Sr). All essential amino acids were greater in oat grains under LEG systems compared with other systems except lysine, histidine and methionine. Both LEG systems also increased 12 out of 13 non-essential amino acids in oat grains. Total oat N, C and S required for amino acid synthesis tended to be greater in organic systems. Soil N, C and S were highly correlated with total oat amino acids under organic systems compared to CNV. Organic LEG had significantly greater vitamin B1 than MNR and CNV. These results suggest that nutrient concentrations of oat grains were greater in organic systems compared to CNV systems, and the increase could be partially explained by the long-term soil management differences between the systems.

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.

In order to increase ecological horticulture in Sweden, it is necessary to increase productivity while reducing working hours. To improve the relevance of research results as a base for such transitions, a Participatory Learning and Action Research (PLAR) group was added to a conventional research project that aimed to find options for using green manure as a multifunctional tool in vegetable production. The project consisted of four work packages looking at different aspects of a system of interest defined by researchers. The PLAR group sought to evaluate the agronomic outcome of the conventional research outputs but came to add qualitative experience of using the different manuring methods tried. The article reports on the evaluation of the PLAR activities as well as on issues of cooperation and understanding The difficulties and constrains that arose revealed the limitations of conventional research as a means for supporting ecological horticulture transitions, but using PLAR as an ‘add on method’ is also shown to be inadequate for helping producers effect the transitions required. Discussion on the robustness of the data generated and the stability of the approach show the importance of using approaches that are fit for practice when extending research to develop ecological horticulture to include participation with practitioners. Moving from conventional research approaches to trans-disciplinary approaches is not easy and includes the need to relate the contextual knowledge of farmers to the abstract knowledge of scientists.

Biochar is considered a promising option for the development of sustainable agroecosystems, due to its diverse agronomic and environmental benefits. In this context, the aim of this study was to carry out a bibliometric analysis on biochar research in Brazil within an agricultural context, including investigating the raw materials most employed for its production in the country. The analysis was conducted based on a search for scientific articles (peer-reviewed papers) at the Web of Science database (WoS Core Collection) from 2003 to 2020 specifically in Brazil. A performance analysis was carried out by applying a descriptive and metric approach concerning research constituents (authors, institutions, countries and keywords) and science mapping to clarify scientific collaborations and cognitive and intellectual structure patterns regarding the biochar domain in Brazilian research, using the VOSviewer software. The obtained studies were also analyzed individually to classify the different raw materials employed in biochar production. A total of 261 scientific articles met the screening criteria, indicating that the beginning of biochar publications in Brazil took place in 2003, increasing until 2015 and peaking in 2021. Institutions and authors with the highest publication contributions were the Brazilian Agricultural Research Corporation (EMBRAPA) (Novotny E.), São Paulo University (USP) (Cerri C.) and Federal Lavras University (UFLA) (Melo L.). The United States, Spain, Australia, Germany and the Netherlands present the most collaborations on biochar research with Brazil. The biochar domain was highly associated with the following keywords: biochar, pyrogenic carbon, pyrolysis, charcoal, immobilization, black carbon, soil fertility and soil and characterization. Raw materials of plant origin were the most employed in biochar research in Brazil, with wood residues being the most studied and residues originated from the sugar-energy industry (straw, bagasse and filter cake) identified as exhibiting high potential for future studies. Poultry litter is the most promising animal waste for biochar production, while the use of biosolids can be innovative, contributing to the consolidation of biochar as an option for serious urban waste sanitary management problems.