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[学术文献 ] 保障水与粮食安全的国际农业用水管理先进技术与经验 进入全文
中国知网
水与粮食安全是世界各国和相关国际组织持续关注的议题。受人口增长、耕地条件、水资源约束及气候变化影响，粮食安全问题需要通过持续改善提升现有灌排工程设施，发展新的灌排工程设施，应用先进管理技术和措施，以及改革管理体制机制等综合措施来解决。灌排系统是一个包含农业生产、生态及水资源循环过程的大系统工程，其中灌溉和排水对生态环境影响日益受到关注。在开展农业节水的同时要关注节水的尺度效应，在提高灌区灌溉水利用率的同时，需综合考虑灌排系统的水循环过程和水资源整体利用效率、效益及对生态环境的影响。研究总结了国际上保障水与粮食安全的农业用水管理先进技术与经验，包括世界灌排发展现状与趋势、挑战、对策和创新，以及基于蒸散发管理的节水概念、技术和措施等内容。
[学术文献 ] Drying-wetting cycles affect soil structure by impacting soil aggregate transformations and soil organic carbon fractions 进入全文
sciencedirect
Drying-wetting (DW) cycles influence the formation and breakdown of soil aggregates and consequently impact the physical protection of soil organic carbon (SOC). However, the interaction between soil structural dynamics and SOC fraction changes driven by DW cycles is still unclear. Herein, aggregation pathways were tracked by using rare earth oxides (REOs) as tracers. The recombined soil columns were subjected to different DW frequencies (0, 1, 2, 4 and 8 cycles) and two DW intensities (low intensity, Q1; high intensity, Q2). During a 56-day incubation, aggregate distributions, mean water diameter (MWD), REO concentrations, the contents of SOC and its fractions (particulate organic carbon, POC; mineral-associated organic carbon, MOC) were measured. The results showed that MWD markedly increased with DW frequencies regardless of DW intensities and was significantly related to the relative changes of 2–0.25 mm aggregates (P < 0.05). Based on transformation paths, DW cycles stimulated the breakdown of > 0.25 mm aggregates and the aggregation of < 0.053 mm aggregates, thus leading to the increasing formation of 0.25–0.053 mm aggregates. Soil aggregate turnover time was affected by DW intensities and extended with DW frequencies (P < 0.05). Soil aggregate turnover time was displayed in the order of < 0.25 mm aggregates < 2–0.25 mm aggregates < 5–2 mm aggregates. MOC concentration exhibited an increasing trend with DW frequencies. A higher loss of SOC under high DW intensity resulted from more exposure of POC through soil aggregate breakdown. POC concentration was sensitive most to the 2–0.25 mm aggregates turnover time. The structural equation model (SEM) revealed that DW cycles exerted remarkable effects on MWD by impacting SOC fractions and soil aggregate transformations. Overall, our findings suggested that soil aggregate breakdown and formation processes, rather than aggregate size distributions, were more of a concern when evaluating the effects of DW cycles on soil structural stability.
[科技报告 ] Innovation for Sustainable Productivity Growth 进入全文
OECD
Total support to the agricultural sector across the 54 countries covered by this report averaged USD 842 billion per year during 2021-23. Many of the countries covered by the OECD Agricultural Policy Monitoring and Evaluation report provide support to their sectors, using policies that include market price support (tariffs and other border measures, MPS) that changes the price farmers receive for their products, or via various forms of budgetary transfers, such as output or input subsidies, payments for environmental services, or general services such as infrastructure development.
[科技报告 ] Agricultural Policy Monitoring and Evaluation 2024 进入全文
OECD
This annual report monitors and evaluates agricultural policies in 54 countries, including the 38 OECD countries, the five non‑OECD EU Member States, and 11 emerging economies. It finds that despite some modest declines in recent years, support to agriculture has remained close to recent historical highs. While changes in support have been limited, agricultural policies have been both reactive and proactive, boosting the sector’s capacity to respond to current challenges while aiming to ensure that food systems are fit for purpose as future conditions evolve. This year’s report focuses on policies fostering sustainable productivity growth in agriculture. Governments are applying a large variety of approaches to improve productivity while preserving natural resources and reducing agricultural greenhouse gas emissions. The report notes, however, that clearly defined targets related to sustainable productivity growth and measurable indicators of progress are important to ensure that policies achieve their stated objectives. The report also notes that making more effective use of producer support to promote innovation and environmental sustainability on the farm, and refocusing overall support towards targeted R&D, can better leverage public spending to deliver public goods and sustainable productivity growth. In line with the 2022 OECD Agriculture Ministerial Declaration, the report identifies a seven-point policy agenda for making agriculture more sustainable, productive and resilient, and for improving the effectiveness and efficiency of agricultural support and markets.
[科技报告 ] The challenge of measuring and achieving sustainable agricultural productivity growth 进入全文
OECD
Overcoming the challenges facing food systems requires producing more with fewer inputs, while reducing the impact on natural resources. Sustainable agricultural productivity growth involves using innovative technologies and practices that increase productivity, while also reducing pressures on the environment. While the economic productivity of agriculture is fundamental to achieve the UN Sustainable Development Goal 2 of ending hunger, achieving food security and improved nutrition, and promoting sustainable agriculture, it is not enough. Agricultural activity growth also needs to ensure environmental and social sustainability.
[学术文献 ] 全球农业贸易规则演变与中国粮食安全战略 进入全文
中国知网
当前,全球农业贸易规则正从多边治理向多边—双边双重治理转换、由低标准治理向高标准治理提升、由边境规则向边境内规则拓展、由规则协调刚性向包容并蓄转变,这是全球地缘政治经济格局变动下国家竞争的结果。文章重点考察了农业贸易规则演变对中国粮食安全的影响。研究发现,农业市场准入规则加剧了粮食贸易逆差,投资规则可能诱发跨国公司在华垄断,高标准SPS规则降低了农产品竞争力,而知识产权保护、环境保护、电子商务、竞争中性等边境内规则对中国粮食安全产生了多重影响。在此基础上,文章从构建全球自由贸易区网络、主动对接和积极构建农业贸易规则、构建竞争有序的粮食市场体系、加强外商投资的引导与监管、加快培育国内粮食龙头企业、完善粮食安全应急保障机制等六个方面提出强化粮食安全的战略举措。
