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In European grassland landscapes, grazing and mowing play a key role for the maintenance of high-quality habitats that host important bird populations. As grasslands are also key resources for cattle feeding, there is a need to develop management strategies that achieve the double objective of production and biodiversity conservation. The objective of this study was to use a modelling approach to generate recognisable patterns of bird dynamics in farms composed of different land use proportions, and to compare their production and ecological dimensions. We developed a dynamic model, which linked grassland management to bird population dynamics at the field and farm levels. The model was parameterised for two types of suckling farms corresponding to contrasting levels of grassland intensification and for two bird species of high conservation value. A viability algorithm was used to define and assess viable management strategies for production and ecological performance so as to draw the shape of the relationship between both types of performances for the two types of farms. Our results indicated that, at the farm level, there was a farming system effect with a negative and non-linear relationship linking performance. Improving bird population maintenance was less costly in extensive farms compared with intensive farms. At the field level, the model predicted the timing and intensity of land use, maximising either production or ecological performance. The results suggested that multi-objective grassland management would benefit from public policies that consider levels of organisation higher than the field level, such as the farm or the landscape. [ABSTRACT FROM PUBLISHER]

Behaviour of nocturnal insects is routinely observed under red light, but it is unclear how the behaviour under red light compares to behaviour in complete darkness, or under a source of white light. Here, we measure movement behaviour of the nocturnal carabid beetle Pterostichus melanarius Illiger (Coleoptera: Carabidae) using camera recording under a near-infrared (nir), red or white radiation source. Red light significantly reduced movement speed in females similar to the effect of white light and different from nir. Also movement activity and pause length were affected by radiation source, with a significant difference between nir and white light, and with intermediate values in red light. The results presented here indicate that P. melanarius has different movement behaviour under the three radiation sources and suggest that nir rather than red radiation is most appropriate for measuring behaviour in total darkness. However, in the field total darkness is rare both because of natural light sources such as the moon and stars but increasingly also because of ecological light pollution, and therefore red light may still be of use for observing ecologically and practically relevant natural night-time behaviour. [ABSTRACT FROM AUTHOR]

Cow-calf systems utilise grazing of native grasslands for beef cattle propagation and constitute the principal livestock activity in the Pampas and Campos areas. Cow-calf system sustainability is questioned because of their low production levels and negative environmental impact. Ecological intensification has been proposed as a way out that constitutes an alternative to dominant discourses based on increasing external-input use. There is, however, a considerable gap between the availability of scientific knowledge to promote the ecological intensification of cow-calf systems and farmers' practices. This gap between scientific knowledge availability and farmers' practices can be made explicit, and its consequences for systems performance can be explored through a conceptual model. Conceptual models are tools to build a systems view of the interactions among the production system's state variables, farm management, and resulting system performance. In this paper, we develop a conceptual model of cow-calf systems on native grasslands of the Pampas and Campos regions to support the diagnosis and redesign of farm systems towards ecological intensification. We apply the conceptual model to analyse cow-calf systems in Uruguay, drawing on a survey among 250 Uruguayan livestock farmers. Using the model, we show that in Uruguay, the level of implementation of strategic, tactical, and decision-supporting techniques is low. Consequently, most farms have poor control of the grazing intensity and timing of main events in the production cycle. This results in ample room to improve the productive and environmental performance of most cow-calf farms in Uruguay. We distinguished three broad types of cow-calf systems based on the degree of implementation of techniques, the evolution of state variables throughout the year, and productive indicators. These types imply different departure points and strategies for a sustainability transition process. The conceptual model designed in this paper may support the cow-calf systems sustainability transition in the context of co-innovation processes by aiding the interactive diagnosis and redesign of farm systems., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Vegetables are commonly produced with high inputs of pesticides and fertilisers to boost production and meet cosmetic market standards. Yet, reports on the relationships between agrochemical inputs and crop productivity are scattered and an overview is missing. We assessed the relationship between pesticide and nutrient inputs and crop productivity for five vegetable crops in the south of Uruguay at field and farm level and explored the relation with farm resource endowment. We analysed crop yield and input use for tomato, onion, sweet potato, and strawberry with a dataset of 82 farms and 428 fields constructed between 2012 and 2017. Clear crop-specific patterns in pesticide and nutrient input levels were found, despite considerable variation across fields within the same crop. Strawberry and long cycle tomato had the greatest pesticide input regarding of the number of applications (20 and 18, respectively) and pesticide load (21 kg AI ha -1 ). Cumulative nutrient inputs were greatest for long cycle tomato (1127 kg ha -1 ). The relationships between inputs and yield were weak or non-significant, indicating inefficiencies and overuse of inputs, and there was no agronomical rationale for input use. We found substantial variation in management practices between fields and farms. In several cases, 21% of the fields and 17% of the farms producing onion, strawberry and tomato, attained relatively high yield levels with limited input levels. Yield and input use levels were not related to farm resource endowment. Our findings question the efficiency of the current high levels of pesticide and nutrient inputs in Uruguayan vegetable systems. The inputs may pose environmental and human health risks and in most cases did not increase yields. Learning from positive deviant farmers in combination with guided farm redesign, high-quality extension services, and use of context-specific knowledge and technologies may equip farmers to use more sustainable management practices., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Quantification of the movement of insects at field and landscape levels helps us to understand their ecology and ecological functions. We conducted a meta-analysis on movement of carabid beetles (Coleoptera: Carabidae), to identify key factors affecting movement and population redistribution. We characterize the rate of redistribution using motility μ (L2 T-1), which is a measure for diffusion of a population in space and time that is consistent with ecological diffusion theory and which can be used for upscaling short-term data to longer time frames. Formulas are provided to calculate motility from literature data on movement distances. A field experiment was conducted to measure the redistribution of mass-released carabid, Pterostichus melanarius in a crop field, and derive motility by fitting a Fokker-Planck diffusion model using inverse modelling. Bias in estimates of motility from literature data is elucidated using the data from the field experiment as a case study. The meta-analysis showed that motility is 5.6 times as high in farmland as in woody habitat. Species associated with forested habitats had greater motility than species associated with open field habitats, both in arable land and woody habitat. The meta-analysis did not identify consistent differences in motility at the species level, or between clusters of larger and smaller beetles. The results presented here provide a basis for calculating time-varying distribution patterns of carabids in farmland and woody habitat. The formulas for calculating motility can be used for other taxa.

In the last decade the multifunctional agriculture (MFA) concept has emerged as a key notion in scientific and policy debates on the future of agriculture and rural development. Broadly speaking, MFA refers to the fact that agricultural activity beyond its role of producing food and fibre may also have several other functions such as renewable natural resources management, landscape and biodiversity conservation and contribution to the socio-economic viability of rural areas. The use of the concept can be traced to a number of wider societal and political transformation processes, which have influenced scientific and policy approaches in different ways amongst countries and disciplines. This paper critically discusses various existing research approaches to MFA, both from natural and social sciences. To this aim different strands of literature are classified according to their focus on specific governance mechanisms and levels of analysis into four main categories of research approaches (market regulation, land-use approaches, actor-oriented and public regulation approaches). For each category an overview of the state-of-the-art of research is given and an assessment is made of its strengths and weaknesses. The review demonstrates that the multifunctionality concept has attracted a wealth of scientific contributions, which have considerably improved our understanding of key aspects of MFA. At the same time approaches in the four categories have remained fragmented and each has limitations to understand MFA in all its complexity due to inherent constraints of applied conceptualizations and associated disciplinary backgrounds. To go beyond these limitations, we contend, new meta-level frameworks of analysis are to be developed that enable a more integrated approach. The paper concludes by presenting the main lines of an integrative, transitional framework for the study of MFA, which analyses multifunctional agriculture against the background of wider societal change processes towards sustainability and identifies a number of key elements and research challenges for this.

The Ricker model extended with a linear term was used to model the dynamics of a potato cyst nematode population on different potato cultivars over a wide range of population densities. The model accounts for contest and scramble competition and between-year carryover of unhatched eggs. Contest competition occurs due to the restricted amount of available root sites that are the feeding source of the female nematode. Nematodes not reaching such a feeding site turn into males and do not contribute to a new generation. Scramble competition results in a decrease of the number of eggs per cyst at high densities due to the decrease in the food supply per feeding site. At still higher densities, the size of the root system declines; then dynamics are mostly governed by carryover of cysts between subsequent years. The restricted number of three parameters in the proposed model made it possible to calculate the equilibrium densities and to obtain analytical expressions of the model's sensitivity to parameter change. The population dynamics model was combined with a yield-loss assessment model and, using empirical Bayesian methods, was fitted to data from a 3-year experiment carried out in the Netherlands. The experiment was set up around the location of a primary infestation of Globodera pallida in reclaimed polder soil. Due to a wide range of population densities at short distances from the center of the infestation, optimal conditions existed for studying population response and damage in different cultivars. By using the empirical Bayesian methods it is possible to estimate all parameters of the dynamic system, in contrast to earlier studies with realistic biological models where convergence of parameter estimation algorithms was a problem. Applying the model to the outcome of the experiment, we calculated the minimum gross margin that a fourth crop needs to reach in order to be taken up in a 3-year rotation with potato. An equation was derived that accounted for both gross margin changes and nematode-related yield loss. The new model with its three parameters has the right level of complexity for the amount and type of collected data. Two other important models from the literature, containing five and 10 parameters respectively, may at this point turn out to be less appropriate. Consequences for research priorities are discussed and prediction schemes are taken in consideration.

In different parts of the world, there is an urgent need for redesigning and innovating farming systems. Such a process may be supported by model-based explorations that enable ex-ante evaluation of a broad range of alternatives. Since a variety of viable patterns of farm development exists related to farm resource endowment and farmer's strategy, model-based explorations should be able to capture the existing variation in resource endowment and strategies in order to have impact on strategic farm management. In this paper, we present an overview of the model-based explorative method based on the MILP model Farm Images, applied to explore options for sustainable development of vegetable farms in Canelón Grande, Uruguay. The method is used to gain insight into the impact of current farm resource endowment on the possibilities for sustainable development and on the resource use efficiency at farm scale. We maximized farm income for 128 different farm types in an environment-oriented scenario and in an income-oriented scenario. Farm types were defined by combining 4 farm sizes, 2 labor endowments, 4 irrigation endowments, 2 soil quality combinations and 2 mechanization levels. The results demonstrate a strong impact of farm resource endowment on possibilities for sustainable development, as well as synergy between labor, land and irrigated area on resource-use efficiency at farm scale. Farms with 10ha of land or less, representing 47% of the farms in the Canelón Grande region, could only achieve a family income higher than the average income of Uruguayan families when the irrigated area was ca. 40% of the farm area. The achievement of environmental targets was less costly in terms of income on farms with a low rather than high labor availability per unit area and on farms with irrigation facilities.

In 1-year experiments, the final population density of nematodes is usually modeled as a function of initial density. Often, estimation of the parameters is precarious because nematode measurements, although laborious and expensive, are imprecise and the range in initial densities may be small. The estimation procedure can be improved by using orthogonal regression with a parameter for initial density on each experimental unit. In multi-year experiments parameters of a dynamic model can be estimated with optimization techniques like simulated annealing or Bayesian methods such as Markov chain Monte Carlo (MCMC). With these algorithms information from different experiments can be combined. In multi-year dynamic models, the stability of the steady states is an important issue. With chaotic dynamics, prediction of densities and associated economic loss will be possible only on a short timescale. In this study, a generic model was developed that describes population dynamics in crop rotations. Mathematical analysis showed stable steady states do exist for this dynamic model. Using the Metropolis algorithm, the model was fitted to data from a multi-year experiment on Pratylenchus penetrans dynamics with treatments that varied between years. For three crops, parameters for a yield loss assessment model were available and gross margin of the six possible rotations comprising these three crops and a fallow year were compared at the steady state of nematode density. Sensitivity of mean gross margin to changes in the parameter estimates was investigated. We discuss the general applicability of the dynamic rotation model and the opportunities arising from combination of the model with Bayesian calibration techniques for more efficient utilization and collection of data relevant for economic evaluation of crop rotations.