Diversification of cropping systems has been proposed as a major mechanism to move towards sustainable cropping systems. To date, a diversification option that has received little attention is ...introduction of ley pastures into cropping systems, but the use of ley pastures is challenged by most future-oriented scenarios aiming to feed the world sustainably. In these scenarios, ruminant livestock feed only on permanent pastures, while cropping systems focus completely on production of crop-based human food. Diversification of cropping systems with ley pastures is thus compromised by knowledge gaps and future-oriented policy options. Here, we review ecosystem services provided by introducing ley pastures into cropping systems to increase sustainability of agriculture, discuss types of ley pastures and their management liable to promote these services, and raise future challenges related to introducing ley pastures into cropping systems. We conclude that (1) ley pastures provide a large set of input (soil conservation, nutrient provision and recycling, soil water retention, biological control of pests) and output (water purification, climate regulation, habitat provision for biodiversity conservation, forage production) ecosystem services of primary importance to cropping systems and society, respectively, as long as their spatial and temporal insertion within cropping systems is well-managed; otherwise, disservices may be produced. (2) To benefit from ecosystem services provided by ley pastures in cropping systems while limiting their disservices, it appears necessary to define a safe operating space for ley pastures in cropping systems. Moving towards this space requires changing plant breeding programs towards multiservice ley pastures, producing knowledge about emerging ways of introducing ley pastures into cropping systems (e.g., living mulch, green manure) and better quantifying the bundles of ecosystem services provided by ley pastures in cropping systems.
In response to the sustainability issues that agriculture faces in advanced economies, agroecology has gained increasing relevance in scientific, political, and social debates. This has promoted ...discussion about transitions to agroecology, which represents a significant advancement. Accordingly, it has become a growing field of research. We reviewed the literature on and in support of farm transitions to agroecology in advanced economies in order to identify key research challenges and suggest innovative research paths. Our findings can be summarized as follows: (1) Research that supports exploration and definition of desired futures, whether based on future-oriented modeling or expert-based foresight approaches, should more explicitly include the farm level. It should stimulate the creativity and design ability of farmers and other stakeholders, and also address issues of representation and power among them. (2) Research that creates awareness and assesses farms before, during or after transition requires more holistic and dynamic assessment frameworks. These frameworks need to be more flexible to adapt to the diversity of global and local challenges. Their assessment should explicitly include uncertainty due to the feedback loops and emergent properties of transitions. (3) Research that analyzes and supports farms during transition should focus more on the dynamics of change processes by valuing what happens on the farms. Research should especially give more credence to on-farm experiments conducted by farmers and develop new tools and methods (e.g., for strategic monitoring) to support these transitions. This is the first review of scientific studies of farm transitions to agroecology. Overall, the review indicates that these transitions challenge the system boundaries, temporal horizons, and sustainability dimensions that agricultural researchers usually consider. In this context, farm transitions to agroecology require changes in the current organization and funding of research in order to encourage longer term and more adaptive configurations.
This work focuses on the assessment of the potential environmental benefits associated with the diversity of organic fertilisers available in the AGRIBALYSE database. Under the eco-design ...perspective, the shift from mineral to organic fertilisation regimes must not be over simplified, as fertilisation of each crop has an effect on the whole crop rotation. This work contrasts the environmental impacts of conventional crop rotations with equivalent eco-designed ones, featuring partial substitution of mineral by organic fertilisers at a level that the current yield is maintained. Two eco-design strategies involving AGRIBALYSE were devised. The first consists of retrofitting existing single crop processes by replacing conventional fertiliser inputs with newly available residual organic fertiliser processes. The second consists of eco-designing agricultural systems (i.e. technical itineraries representing crop rotations or crop sequences) by partially substituting mineral with newly available residues-based organic fertilisers. In both cases, it is necessary to adjust the fertiliser-related direct field emissions accordingly. In the second strategy, large amounts of organic fertilisers are input to replace mineral ones (tonnes vs. kg), and therefore overall impacts (i.e. impacts across impact categories) increase considerably, yet this effect is minimised when considering the alternative waste disposal pathways associated with the mineral fertilisation strategy (i.e. mineral fertilisation + disposal of the amount of organic residues necessary to deliver an equivalent level of fertilisation). The expanded functionality of a cropping system consuming organic waste-derived fertilisers (i.e. fertilisation + organic waste disposal) should be considered in comparative LCAs.
•Eco-design of crop rotations demands an agronomic validation of fertiliser substitution.•The provision of organic fertilisers contributes marginally to impacts in most cases.•Exceptions occur when large inputs of energy-intensive organic fertilisers take place.•The expanded functionality of systems consuming waste-based fertilisers should be considered in comparative LCAs.
The potential contributions of exogenous organic matters (EOMs) to soil organic C and mineral N supply depend on their C and N mineralization, which can be assessed in laboratory incubations. Such ...incubations are essential to calibrate decomposition models, because not all EOMs can be tested in the field. However, EOM incubations are resource‐intensive. Therefore, easily measurable EOM characteristics that can be useful to predict EOM behaviour are needed. We quantified C and N mineralization during the incubation of 663 EOMs from five groups (animal manures, composts, sewage sludges, digestates and others). This represents one of the largest and diversified set of EOM incubations. The C and N mineralization varied widely between and within EOM subgroups. We simulated C and N mineralization with a simple generic decomposition model. Three calibration methods were compared. Individual EOM calibration of the model yielded good model performances, while the use of a unique parameter set per EOM subgroup decreased the model performance, and the use of two EOM characteristics to estimate model parameters gave an intermediate model performance (average RMSE‐C values of 32, 99 and 65 mg C g−1 added C and average RMSE‐N values of 50, 126 and 110 mg N g−1 added N, respectively). Because of the EOM variability, individual EOM calibration based on incubation remains the recommended method for predicting most accurately the C and N mineralization of EOMs. However, the two alternative calibration methods are sufficient for the simulation of EOMs without incubation data to obtain reasonable model performances.
Both dilute and concentrated vinasse can be spread on agricultural fields or used as organic fertilizer. The effects of different characteristics of the original raw material on the biochemical ...composition of vinasse and their C and N mineralization in soil were investigated. Vinasse samples were obtained from similar industrial fermentation processes based on the growth of microorganisms on molasses from different raw material (sugar beet or sugar cane) and vinasse concentration (dilute or concentrated).
The nature of the raw material used for fermentation had the greatest effect on the nature and size of the resistant organic pool. This fraction included aromatic compounds originating from the raw material or from complex molecules and seemed to be quantitatively related to acid-insoluble N. Samples derived from sugar beet were richer in N compounds and induced greater net N mineralization. The effect of evaporation varied with the nature of the raw material. Concentration led to a slight increase in the abundance of phenolic compounds, acid-insoluble fraction, and a slight decrease in the labile fraction of vinasses partly or totally derived from sugar beet. The effect of the dilute vinasse from sugar cane was greater. The concentrated vinasse had a smaller labile fraction, induced N immobilization at the beginning of incubation, and exhibited greater N concentration in the acid-insoluble fraction than the dilute vinasse.
A methodology is presented to assess the sensitivity of a complex model involved in integrated assessment and modeling approaches to spatial factors. The application considers the ...spatially-distributed agro-hydrological model TNT2, and its sensitivity to soil characteristics and their spatial distribution (soil pattern). The final goal is to identify soil input data that require more accurate description (measurement) and the relevant spatial resolution for soil information. Based on methods commonly used for non-spatially-distributed models (Morris method and a fractional factorial design with ANOVA), the proposed approach is innovative in the way that spatial input factors are considered in the global sensitivity analysis. The global sensitivity analysis is performed in three steps (i) screening among soil input data to identify those that most affect model outputs, (ii) quantifying the sensitivity of TNT2 to the dominant soil input factors and their interactions when considering a single soil and (iii) incorporating the soil pattern into the global sensitivity as an explicit input factor. The results indicate differences in the hierarchy of influential input factors between the screening and quantitative methods. The model's low sensitivity to spatial patterns provides recommendations for further field sampling campaigns. The hierarchical approach developed in this paper is based on sensitivity analysis methods with relatively low computational demand. The approach is generic and applicable to any complex spatial model.
•A methodology is applied to analyze the sensitivity of a model to spatial inputs.•Influence of the spatial distribution of soil properties on model outputs is discussed.•Results provide insights for further field sampling campaigns and model development.
In a context of economic and environmental concerns in agriculture, legumes appear to be suitable alternative crops to diversify current cropping systems and reduce their dependence on synthetic ...nitrogen (N) fertiliser and protein from imported soya bean. However, legume-based cropping systems may increase N losses through nitrate leaching if the N available from legumes does not coincide with subsequent crop requirements. To help agricultural advisers manage N in these systems, we adapted the decision-support system Syst’N®, designed to assess N losses in cropping systems, to simulate three annual and one perennial legume crops: pea, faba bean, soya bean and lucerne. To this end, we adapted and simplified existing submodels of legume functioning to include them in Syst’N, to keep the latter simple. We adapted the submodels “BNF” (i.e. biological N fixation) from the STICS model and “dormancy” from the CropSyst model. We also added the ability to enter the flowering date to improve predictions (improvement in N fixation’s rRMSE from 57% to 41% and EF from 0.57 to 0.77). The equations and associated parameter set developed for the four legume crops yielded satisfying predictions of crop biomass (rMBE = 9%, EF = 0.82, rRMSE = 39%) and N content (rMBE = 5%, EF = 0.76, rRMSE = 37%). These performances support the philosophy of Syst’N® that requires minimising the number of additional parameters for users when representing new crops or processes.
•The decision-support system Syst’N® was adapted to simulate diverse legume crops.•Submodels of legume functioning were adapted and simplified to keep Syst’N® simple.•The ability to enter the flowering date to improve predictions was added.•Predictions of soil water and N content were less accurate.
The forms and presence itself of farming in coastal territories changed profoundly in the 20th century. By contrast with other interface farming systems, such as mountain or peri-urban farming, ...coastal farming has rarely been studied as such and has not, until now, been considered as a useful category to describe and analyse production systems. The aim of this article is thus to address the relevance of such a categorization, using empirical data collected in Brittany (France) as well as contextual indicators, but also by carrying out a systemic qualitative-quantitative analysis, questioning the forms, depth and continuity of marine influence on farming activities at the local scale. We show that specific traits of coastal farming do indeed exist. A greater diversity of farming systems exists in coastal strip than inland at the regional scale. Four configurations of coastal farming were identified, which result from distinct dynamics and combinations of urbanization and environmental pressures on agriculture. But these specific features cannot be revealed without a comprehensive and historicized approach of its interactions with the coastal zone as a territory, rather than a biophysical milieu. These configurations are characterized in the typical spatial extent of coastal farming and spatial patterns of the transition to inland farming (gradient, discontinuities).
•Coastal farming is a relevant category of analysis of farming systems.•A greater diversity of farming systems exists in coastal strip than inland at the regional scale.•Four configurations of coastal farming emerge from distinct combinations of urbanization and environmental pressures.•Qualitative-quantitative analysis integrating time, is required to capture the complexity of coastal-farming configurations.
In response to criticism of current specialized and input-intensive agriculture, diversified farming systems (DFS) have increased in popularity. The most advanced forms of DFS include perennial ...components (e.g., perennial crops, trees), functionally different plants and livestock, and landscape heterogeneity. These characteristics make it more difficult to assess DFS in agricultural sciences, which have focused to date mainly on low-diversity systems. We provide an overview of the main methodological issues involved in assessing DFS, and their potential solutions. We identify five key methodological challenges for assessing DFS: i) combining conceptual frameworks from different disciplines to develop a holistic view of DFS multi-performance; ii) characterizing DFS structure from a functional perspective to define the relevant spatial extent to assess them; iii) considering DFS ontogeny i.e. the time required for DFS to establish, reach maturity and achieve a dynamic steady state when assessing their performance; iv) aggregating and mapping multiple performance indicators to integrate the range of products and services generated by DFS and to reveal potential synergies and antagonisms; v) defining and characterizing the reference systems used to compare DFS, as systems might differ in history, composition, management, soil-climate, and sociotechnical conditions. These challenges underline the need to overhaul assessments in agricultural sciences (e.g., agronomy, animal science, economics, ecology) to identify whether, and under what conditions, DFS are relevant and sustainable options for farmers. They also come with available options for researchers to proceed with this overhaul.
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•Diversified farming systems use agrobiodiversity in space and time to generate ecological processes replacing external inputs.•We discuss the main methodological challenges involved in assessing diversified farming systems.•We question the reference framework and indicators used and their spatial and temporal extents.•We recommend in-depth reflection about the reference systems or thresholds chosen for interpretation.•We recommend a complete overhaul of the methods used to assess diversified farming systems.
The organic compositions of five different sludges and their residues obtained by neutral detergent extraction (NDF) were characterized by pyrolysis-GC/MS, and the composition of their “soluble” ...fractions was deduced. These organic characteristics were used to explain the observed mineralization when the sludges were added to a soil under controlled conditions.
Certain of the biochemical compounds revealed by pyrolysis-GC/MS, such as N-containing compounds, ketones and polysaccharides, were common to all five sludges, but in different proportions. Lignin-derived products were, in contrast, only present in two sludge samples, and were especially abundant in the sludge composted with green wastes and wood pieces. Aliphatic compounds and acids probably originating from lipids were only observed in some of the pyrograms. Although the compositions of the different NDF varied, some global trends were apparent. The sludge NDF pyrolysates contained compounds originating from lignins, cellulosic and non-cellulosic material. Some of the proteins and peptides evidenced by pyrolysis in the total sludge remained after extraction in some residues, although they were expected to be solubilized in neutral detergent. The soluble residue consisted mainly of simple sugars, proteins, peptides and lipids. However, the solubilization of some specific compounds varied with the global composition of the sludge. No specific recalcitrant compounds could be evidenced in the neutral detergent extract.
Relationship were established between relative abundance of some compounds and C and N mineralization rates: C mineralization rate after 14 days of incubation was correlated with the cumulated relative areas of (ketones
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aliphatics
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acids), C mineralization rate at day 168 with those of (phenol
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benzene) and N mineralization rate with those of ketones, and N-containing compounds.
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