Agronomy for Sustainable Development最新文献

Nitrification and nitrogen (N) immobilization are important pathways in soil N transformations, involving soil N loss and retention, respectively. The ratio of nitrification to N immobilization generally reflects the potential risk of soil N loss. However, little is known about the response of this ratio to anthropogenic carbon (C) and N inputs, but also climate and soil conditions. Here, we aimed to elucidate, for the first time, the impacts of chemical fertilizer and manure application on the ratio of gross nitrification to N immobilization by using ¹⁵N dilution technology, based on ten long-term fertilization trials spanning multiple climatic zones in eastern China. Results showed that manure application differentially increased gross N immobilization rather than nitrification compared to the chemical fertilizer treatment, leading to manure-induced decreases in gross nitrification to N immobilization ratio ranging from 1.2 to 93% across the sites. The decreased gross nitrification to N immobilization ratio in the manure treatment was mainly due to the increased ratio of bacteria to nitrifiers abundance. Manuring was more effective for a decrease in the gross nitrification to N immobilization ratio at sites characterized by high rainfall and low soil pH, as it prevented soil pH decline thereby favoring bacterial abundance and N immobilization. Consequently, manure application resulted in a substantial increase in soil total N accumulation, facilitated by increased microbial N immobilization that promoted microbial biomass. These findings suggest that substituting manure for chemical fertilizer in the areas with high rainfall and acidic soils promisingly reduces soil N loss risk, with positive consequences for soil N retention. This knowledge highlights the potential to reconcile soil N loss and fertility improvement through optimizing regional manure management, which offers valuable insights for the development of a tailored regional fertilization management strategy.

Increasing our understanding of farm resilience drivers to climate-related risks is critical for designing innovative farm systems, especially for smallholders that are highly vulnerable to climatic hazards and expected to follow a pathway toward sustainable development. However, the literature is fragmented on the concepts and methods to measure farm resilience. Moreover, quantitative assessments of options to enhance farm resilience to climate risks are scarce. Resilience can be defined as the ability of a system to recover, reorganize and evolve following external stresses and disturbances. Such definition can be applied to farm systems. In this study, we systematically reviewed how changes in resilience-enhancing attributes (reserves, openness, modularity, tightness of feedbacks and diversity) impacted farm performance and resilience to climate-related risks, with a specific attention to smallholder farms. Our analysis showed that reviewed studies assessed farm resilience using the agricultural and economic dimensions of performance, often excluding the socio-environmental dimensions. To assess performance, the average value of indicators was most commonly employed, sometimes combined with variability metrics or the probability of exceeding a critical threshold. Improving one resilience attribute increased one dimension of farm performance for a given metric in most of the studies, but some studies showed the opposite effect. The lack of comprehensive assessments exploring different attributes and their impact on several dimensions of performance using diverse metrics prevents a robust conclusion on how to improve farm resilience to climate-related risks. Therefore, we recommend to pay more attention to quantitative assessments of farm resilience, including a systematic investigation of the temporal variability of performance and the socio-environmental dimensions of performance. Finally, we emphasize the need to focus on the recovery of smallholder farms after a disturbance, with the goal of achieving growth in farm performance rather than simply reverting to their current state of food insecurity and poverty.

Contextualization of generic scientific knowledge to context-specific farmer knowledge is a necessary step in farmers’ innovation process, and it can be achieved using crop and farm models. This work explores the possibility to simulate a large number of scenarios based on farmers’ descriptions of their environment and practices in order to contextualize the discussion for each participating farmer. It presents a novel framework consisting of six actions divided in three phases, namely, phase I—reaching out to the farmers’ world: (i) project initialization; (ii) determination of the agronomical question anchored in farmers’ context; (iii) characterization of the environment, the management options, and the indicators to describe the system under consideration; phase II—within researchers’ world: (iv) crop model parametrization; (v) translation of model outputs into farmer-proposed indicators; and phase III—back to farmers’ world: (vi) exploration of contextualized management options with farmers. Two communication tools are created during the process, one containing the results of simulations to feed the discussions and a second one to create a record of it. The usefulness of the framework is exemplified with the exploration of soil fertility management with manure and compost applications for sorghum production in the smallholder context of Sudano-Sahelian Burkina Faso. The application of the framework with 15 farmers provided evidence of farmers’ and agronomists’ understanding of options to improve cropping system performance with better organic amendment management. This approach allowed farmers to identify and relate to the scenarios simulated, but highlighted interrogations on how to adapt the crop model outputs to particular situations. Though applied on issues related to tactical change at field level, the framework offers the opportunity to explore broader issues with farmers, such as farm reconfiguration.

Rice is traditionally cultivated worldwide under continuous flooding irrigation. However, in Mediterranean environments, there has recently been a decline in the area of rice cultivation in several producing regions where water supplies for this crop cannot always be guaranteed. Therefore, it is necessary to identify alternative crop management strategies that improve water-use efficiency in order to ensure the sustainability of rice production. It has been postulated that rice production under alternate wetting and drying (AWD) irrigation requires less water than flooding. However, the effects of the AWD system on rice yield components remain unclear, with different trends observed. It has been suggested that the soil properties are a crucial factor in this regard. In fact, drops in rice yields under AWD have been attributed to the low soil organic matter content. Consequently, the incorporation of organic amendments could offset this organic matter deficit, and the subsequent enhancement in rice productivity might also ensure its sustainability in areas where water availability is scarce. This study is the first to analyse how the soils properties, rice yields components, and water productivity were influenced by fresh and field aged biochar applied to rice soils under conventional flooding and AWD using two-threshold (mild and severe). The results showed that the transition from flood management to AWD management has had a significant impact on soil properties and rice yields, though this was dependent on the threshold. Consequently, yield losses occurred under severe AWD conditions in comparison to the flooded systems. Nevertheless, the use of holm oak biochar was found to enhance rice yields under AWD systems, particularly under severe conditions and following the field ageing process. Thus, the combined use of biochar and AWD may be a sustainable strategy to enhance water productivity, which is one of the main objectives in the rice crop.

Farm animals are often lumped together into a single “livestock” entity, reduced to the production of milk and meat and accused of being the cause of major environmental disruptions. However, livestock farming systems are highly diverse, and the functions of livestock encompass multiple dimensions. Based on the methods of comparative agriculture and the quantification of animal labor energy on farms, we explore the changing roles of livestock in a semi-arid area of southern India from the 1950s to the present day. We provide a typology of farms that reveals the evolution of agronomic, economic, food and power supply functions of livestock according to the social diversity of farms of the study area. This study provides key insights to nuance livestock debates: (i) livestock serves a wide range of functions beyond mere food production, (ii) livestock remains necessary for agricultural production despite most agronomic and power supply functions having been impaired by motorized mechanization and the use of synthetic fertilizers, (iii) crop-livestock integration has declined at farm level but has strengthened between farms at area level, (iv) livestock is neither an attribute of the rich nor the poor. This research, therefore, highlights the complexity of livestock farming systems. It combines historical, biophysical, social and ethnographic perspectives with descriptions of unique livestock-related practices that could improve the sustainability of agriculture.

On-farm research with farmer participation is promoted as a transformative approach that increases inclusivity and innovation within agricultural research, ultimately improving research quality and outcomes. However, little is known about the farmers who participate in on-farm research (i.e., research farmers) or how well these farmers represent the broader agricultural community, including farmers not involved in research (i.e., non-research farmers). This gap in knowledge raises questions about both the application and generalizability of on-farm research findings as well as the equitable distribution of on-farm research benefits among farmers. In this study, we examine how research farmers’ behavior and perceptions differ from non-research farmers using two online surveys among US row crop farmers, focused on cover crops (N = 211). We find that among farmers that have engaged in cover cropping, research and non-research farmers are demographically nearly identical; however, there are several significant differences between the two farmer groups’ perceptions, social networks, and on-farm management. Here, we show for the first time that research farmers perceive cover cropping practices as less challenging and are more willing to engage in innovative cover crop practices compared to non-research farmers. Research farmers also exchange farming information with more people and are more willing to share their farm data, compared to non-research farmers. Given these findings, we consider the practical and epistemological consequences of extending insights gained from working with research farmers to the broader agricultural population. Our results highlight potential implications for farmer communication and engagement strategies, especially among those farmers who are not typically involved with on-farm research activities.

Barley (Hordeum vulgare L.) is one of the most important staple crops grown to produce feed for animals worldwide as well as in Iran with considerable surface in the arid and frost-prone climates. The yield gap analysis is an important topic for researchers worldwide as it aims to identify the factors influencing the gap between actual and potential yields and to enhance food security. To date, almost no long-term assessments have been focused on the barley yield gap analysis for the arid and semi-arid environments, particularly categorizing yield gap. In the current study, we therefore calibrated the APSIM-Barley model for three irrigated barley cultivars, validated the model using 31 field experiment reports, and applied it to simulate long-term (1989 to 2019) yields under eight production levels in eight major barley growing locations of Iran (Arak, Hamedan, Kabudarahang, Marvdasht, Neyshabour, Sabzevar, Saveh, and Shiraz). This is the first time that barley yield gaps are categorized into unexploitable, agronomic, and non-agronomic ones in Iran. The results revealed a huge difference between potential and actual yields (on average, 5.4 t ha⁻¹ yield gap) across the studied locations indicating that the farmers could achieve only 38.6% of the potential yield. Yield gap values varied over locations and seasons. Unexploitable, agronomic, and non-agronomic yield gaps in the studied locations averaged 26.7%, 55.9%, and 17.4% of total yield gap, respectively. The major part of the agronomic yield gap in the studied locations was owing to water limitation, which accounted for ~ 40% of the agronomic yield gap, followed by other agronomic (30%), frost-limited (15.8%), cultivar-limited (13.7%), and sowing date-limited (10.4%) yield gaps. Our findings showed that by improving agronomic management practices, particularly water management and farmers’ non-agronomic conditions, the current yield gaps could be reduced considerably in arid and frost-affected locations.

Diversification of agricultural systems in order to integrate off-farm activities, like tourism, is a way to improve the overall system resilience while shaping a project that is eco-friendly as well as socially relevant. However, creating and maintaining such an integrated agritouristic system requires finding a way to organize individual and collective management of activities and commons in order to articulate the founding goals and values with day-to-day functioning. Current modeling tools are limited in the number of aspects they can integrate because of data requirement and because of the high number of dimensions that it involves. In this study, we characterize a case study of integrated agritourism possible pathways leading to a target corresponding to the founding socio-ecological goals of its stakeholders. We propose to build an innovative exploratory model representing the socio-ecological dynamics of an integrated agritouristic system following the qualitative and possibilistic Ecological Discrete-Event Network (EDEN) framework. The model outputs revealed that pathways leading to the target exist and can be more or less straightforward. However, the ability to reach the target can also be lost after a few steps due to a set of biophysical reactions and management decisions affecting sensitive states. Some of these pathways ultimately lead to an agritouristic system that could be considered fully functional but unable to fulfill the socio-ecological goals of its stakeholders. A form of path dependency emerges from these results: transitions involving one or a subset of activities can lead the whole system towards an irreversible and undesirable pathway. It results from a high level of interdependency between the activities. Identifying such lock-in effects can be a first step towards co-constructed path-breaking.

Wheat cultivar mixtures provide a more complex and functional cropping system than monocultures. Their functionality may result in the delivery of agroecosystem services. However, research on cultivar mixture performance has mainly been done in controlled environments. Greenhouses and laboratory experiments do not account for environmental or agronomic factors that may influence the polyculture’s functionality. To fill this research gap, we set up a novel strip-split-block experimental design with three factors (wheat treatment, tillage, and fertilization) in a field long-term trial. We assessed the performance of the modern wheat cultivar Florence-Aurora and the traditional cultivars Xeixa (Triticum aestivum L. subsp. aestivum) and Forment (Triticum turgidum L. subsp. durum) monocultures and their mixture in providing aphid and weed control and promoting crop yield under contrasting tillage practices (moldboard ploughing vs. chisel ploughing) and fertilization (farmyard manure applied or not applied). We analyzed aphid abundance, number of aphids per tiller, parasitism rate, weed abundance and richness, and crop yield. Additionally, we examined wheat establishment, cover, phenology, and height for cultivar characterization. We observed that soil management practices affected some aspects of the cropping system. The wheat cultivars differed in their aphid susceptibility and weed suppression ability, with Florence-Aurora being less suppressant to weeds and more prone to aphid infestation. Most remarkably, our study shows for the first time that mixing wheat cultivars with distinguished traits enhances associational resistance for aphid and weed control. These benefits were specifically important under high weed infestations generated by reduced tillage. Moreover, the yield of Florence-Aurora monoculture and the mixture was found to be influenced by tillage and fertilization. Our study underscores how soil management practices impact the functionality of cultivar mixtures. This emphasizes the need for further field research to better understand the complexity of farming conditions that influence the delivery of agroecosystem services by cultivar mixtures.

In temperate Europe, agroforestry practice is gaining interest due to its potential to enhance carbon (C) sequestration and mitigate greenhouse gas (GHG) emissions in agriculture. To date, the effects of agroforestry on the spatial and temporal dynamics of soil carbon dioxide (CO₂) and methane (CH₄) fluxes are still poorly quantified. Here we present a systematic comparison of soil CO₂ and CH₄ fluxes between agroforestry and monoculture cropland systems for the first time, based on two-year field measurements at three sites on different soils in Germany. Each site had an adjacent alley cropping agroforestry system and monoculture, and the agroforestry was established on former monoculture croplands 1 to 11 years prior to this study. We found that area-weighted soil CO₂ emissions from agroforestry (3.5−8.1 Mg C ha⁻¹ yr⁻¹) were comparable to monocultures (3.4−9.8 Mg C ha⁻¹ yr⁻¹), whereas area-weighted agroforestry generally had higher soil CH₄ uptake (0.4−1.3 kg C ha⁻¹ yr⁻¹) compared to monocultures (0.1−1.2 kg C ha⁻¹ yr⁻¹). Seasonal variations of soil CO₂ and CH₄ fluxes were strongly regulated by soil temperature and moisture, and the spatial variations were influenced by soil texture. Our results suggest that conversion of monoculture cropland to long-term alley cropping agroforestry system could be considered as a sustainable agriculture practice for its great potential for mitigating CH₄ emissions.