Agricultural Systems最新文献

CONTEXT

Understanding the dynamics of potential yields, actual yields, and their drivers is vital for developing sustainable agricultural management practices. Previous studies on rice in China, focusing on either limited experiments, limited driving factors, or short-term periods, reached inconsistent conclusions.

OBJECTIVE

We tried to investigate annual dynamics of rice potential yields, actual yields, and their gaps to distinguish the contributions of climate and technology to yield increases in major rice cultivation areas across China.

METHODS

Herein, using valuable field trials from 1981 to 2018 across 205 agro-meteorological stations and the crop model CERES-Rice, we explored the spatiotemporal trends of rice yields and quantitively separated the contributions of various factors to yield increases across mainland China.

RESULTS AND CONCLUSIONS

A contrasting trend in potential yields was observed, with a decline in the Middle and Lower Reaches of the Yangtze River (MLRYR, −22.4 kg ha⁻¹ y⁻¹) and an increase in the Northeastern China Plain (NECP, 20.0 kg ha⁻¹ y⁻¹). Despite varying regional trends, the national yield gap narrowed to 27 % in 2018. Technological advances were the primary drivers (37.3 kg ha⁻¹ y⁻¹) of yield increases in most areas compared to climate impact (−2.6 kg ha⁻¹ y⁻¹). Particularly in the MLRYR, technological improvements have offset the negative impacts of climate change. Cultivars improvement contributed (14 %–22 %) more than water and fertilizer management did in the main rice-producing regions.

SIGNIFICANCE

Our findings discover the evolving patterns of potential rice yields across China and the underlying drivers, providing scientific evidence for hindering rice yield stagnations by cultivars improvements and field management optimizations.

CONTEXT

Vertical Farming Systems (VFSs) are considered an evolutionary jump in humanity's quest for a reliable, sustainable and healthier food supply, and their design and implementation require bringing multi-stakeholder together to achieve values co-creation. However, there is a lack of the qualitative and quantitative analysis from the perspective of multi-stakeholder's value exchange to explain the complex need relationships among related VFSs and their multi-stakeholder and a lack of the research on VFSs needs (VFSs-N) from the strategic issues view to consider the balance of conflicting needs.

OBJECTIVE

To transform stakeholder needs into stakeholder requirements and capture the comprehensive and consistent VFSs requirements (VFSs-R) list.

METHODS

This paper proposes an approach integrating stakeholder value network (SVN) and strategic issue management (SIM). This study offers a systematic framework to get a VFSs-R list. The SVN is employed for structuring a four-step needs analysis process and viewing multi-stakeholder direct and indirect need relationships as value exchanges for qualitative and quantitative analysis. Integration of stakeholder relationships and SIM is presented to reveal additional insights into the balance of conflicting VFSs-N and reduce the dimensionality of the complex relationships in SVN by issue networks (IN). In addition, based on the above analysis results, needs-to-requirements transformation can be achieved by adding identity (ID), name, description, and rationale.

RESULTS AND CONCLUSIONS

When the framework was applied to the multi-stakeholder needs and requirements analysis of the Robotic Vertical Farming Systems (RVFS) project. We can get 52 needs including 3 conflicting needs and eventually analyse and balance the needs to get a RVFS-R list of 13 well-formed and prioritized requirements.

SIGNIFICANCE

These research results can help the designer identify the relatively more important requirements, whether direct or indirect, and assist the VFSs projects achieve value co-creation among stakeholders.

Context

The agricultural sector has a high potential to reduce greenhouse gas (GHG) emissions. One promising measure is to promote the longevity of dairy cows, as the resulting reduction in replacement heifers reduces the overall GHG emissions of the dairy sector.

Objective

In this study, we analysed the effects of a voluntary policy programme to promote the longevity of dairy cows in Switzerland. We forecasted the effects on agricultural production (milk and meat) and GHG emissions for the Swiss agricultural sector. This voluntary direct programme was implemented by the Swiss government in 2024.

Methods

We used an interdisciplinary method and a data approach that combined several data sources and models. We implemented herdbook data on changes in milk yield and veterinary costs with an increasing number of lactations in a bio-economic farm optimisation approach. The use of an agent-based modelling framework allows the consideration of heterogeneous farm responses to the voluntary direct payment programme, which incentivises an increase in productive life of dairy cows. The results of the agent-based model were then implemented in the GHG model SAGE. Four policy scenarios were simulated. They considered two levels of direct payments (low and high) for the voluntary longevity programme and two fattening strategies for those calves no longer needed for cow replacement (4- and 10-month calf fattening). The results of the longevity scenarios were compared with a reference scenario without these direct payments.

Results and conclusions

Our results show a policy scenario with a high level of direct payments and a 4-month calf fattening strategy has the highest GHG emission reduction potential in Swiss agriculture

(−1.71 % of total agricultural GHG emissions and 998 CHF/t CO₂ equivalent). However, a lower level of direct payments combined with a 4-month calf fattening strategy is more cost-effective with regard to GHG emission reduction (−1.69 % of total agricultural GHG emissions and 471.5 CHF/t CO₂ equivalent). The other scenarios show lower GHG reduction potential and lower cost effectiveness. We find the voluntary direct payment programme has high wind-fall effects because the payments are not linked to changes in longevity but are distributed as long as the average number of lactations of a cow herd is three or more.

Significance

This study is the first to analyse a voluntary policy programme that incentivises farmers to extend the productive life of their dairy cows. Furthermore, both environmental and economic impacts are estimated with a novel mixed modelling approach.

CONTEXT

Quality vegetable seed has the potential to significantly impact nutrition security in sub-Saharan Africa, as the region has the world's lowest per capita production and consumption of vegetables. Moreover, seed companies might have an important role to play, as in Asia, vegetable production and consumption increased rapidly following the expansion of the private seed sector. However, market-driven seed sector development remains contentious, with some celebrating technological advancements and others raising concerns.

OBJECTIVE

This paper contributes to seed systems literature by focusing on the role of vegetable crops and diversity within the private sector. It explores the heterogeneous character of the private sector by studying how different business models of leading vegetable seed companies jointly contribute to sector development in sub-Saharan Africa.

METHODOLOGY

Eighteen in-depth interviews were conducted with leading vegetable seed companies operating in the region. Qualitative tools were selected to translate individual company data into general findings; while thematic analysis was used to pinpoint a private sector perspective and ideal-type analysis was used to construct business model typologies.

RESULTS AND CONCLUSIONS

The results show that seed companies collectively view seed sector development as a linear trajectory involving public and private investments to enable farmers to adopt increasingly advanced seed types, especially hybrids. In this trajectory, different companies take on different roles based on specialization in seed system functions: variety development, seed production, seed dissemination, and seed use. The coexistence of and collaboration between different (private) actors in the vegetable seed sector contribute to plurality and interaction in line with an integrated approach to seed sector development. However, it is not a static condition as company roles evolve with expanding business models in terms of seed system functions and market segments.

SIGNIFICANCE

A general objective of (national) seed policies is to increase farmers' access and choice in terms of quality seed of improved varieties. Seed sector development interventions can enhance inclusivity by focusing on viable and innovative business models for niche markets in terms of farming systems and crop types.

CONTEXT

Environmental policies are increasingly relying on digitalization to improve efficiency. However, there is still a lack of knowledge on farmers' attitudes toward digitally-based environmental policies.

OBJECTIVE

This paper contributes to the literature by providing quantitative insights on farmers' attitudes in such contexts, focusing on the use of digital technologies for the implementation of results-based agri-environmental policy.

METHODS

The analysis focuses on the case study of the implementation of innovative, digitally- and results-based agri-environment and climate schemes in two Mediterranean agri-systems: Mediterranean oak savannah (dehesa) and sloping olive groves (SOG). The assessment relies on a latent class analysis using survey data from a large sample of southern Spanish farmers. In addition, a Step-3 model was used to identify determinants of farmers' class membership.

RESULTS AND CONCLUSIONS

The results show a high degree of heterogeneity in farmers' attitudes, with three different classes of farmers identified: proactive, skeptical, and reluctant farmers (membership probability of 0.62, 0.25, and 0.13, respectively), basically showing positive, mixed, and negative attitudes toward using digital technologies in environmental policies. Class belonging is determined by farm and farmer characteristics (especially the farm's main agri-system, family labor use, and farmer's education level and age), farmer attitudes (toward environmental results and their certification), and specific agri-system features (economic dependence).

SIGNIFICANCE

The results are useful for better tailoring digitally-based agri-environmental policies; the diverse costs and benefits that different farmers can expect from the introduction of digital technologies in policy implementation and monitoring should be carefully considered.

CONTEXT

In Ireland, a national Bovine Viral Diarrhoea (BVD) eradication programme has been effective in reducing national prevalence and has recently been approved by the European Commission. In anticipation of achieving freedom, there is an ongoing discussion regarding appropriate strategies post-eradication to monitor for continued freedom from Bovine Viral Diarrhoea Virus (BVDV) infection of the national cattle sector.

OBJECTIVE

The objective of this study is to evaluate the trade-off between the performance of different testing protocols and their associated costs in monitoring BVDV post-eradication in the national cattle sector. By assessing various testing strategies, including bulk tank milk (BTM) testing, first lactation check tests (FLCT), abattoir tests, and youngstock check test (YSCT), the aim is to provide informed input for implementing a long-term sustainable monitoring strategy.

METHODS

In this study, we apply alternative testing protocols to a modelled cattle population in County Kerry, a region with a bovine population considered to be representative of the entire Irish population. The analysis incorporates combinations of Bulk Tank Milk (BTM) testing First Lactation Check tests (FLCT), abattoir tests, and Young Stock Check Testing (YSCT). The YSCT, which focuses on high-risk herds by collecting blood samples from young, homebred animals between nine and 18 months of age, was a key component of the analysis.

RESULTS AND CONCLUSIONS

All tested protocols are capable of timely detection of a BVDV outbreak, with detection times of less than one year. Our results highlight the impact of reducing herd coverage by YSCT on post-eradication surveillance for BVDV freedom. By evaluating the trade-off between increased costs and shortened time to detection, this study provides valuable insights for selecting an appropriate monitoring policy in post-eradication programmes.

SIGNIFICANCE

The findings of this study offer guidance on balancing costs and detection efficiency in monitoring BVDV post-eradication. Understanding the implications of different testing strategies can aid policymakers in making informed decisions to ensure the continued freedom from BVDV in the national cattle sector. All tested protocols are capable of detecting a BVDV outbreak in a timely manner, with detection times of less than one year. However, our results quantify the impact reducing herd coverage by YSCT within a possible post-eradication surveillance programme for BVDV freedom. We evaluate how more herds covered by young stock sampling shorten the time to detection, but at an increased cost. The trade-off between increase in costs per shortened time to detection provides guidance to choose an adequate policy to implement monitoring of disease freedom in national post-eradication programmes.