Anaerobic Digestion of Agricultural Solid Residues

Abstract

Agricultural residues can be converted to methane-rich gas mixture. Anaerobic biomethane production is an effective process for conversion of a broad variety of agricultural residues to methane to substitute natural gas and medium calorific value gases. Methane generating bacteria (methanogens) and other microbes that help digest dying plants in anaerobic conditions. Agricultural solid residues (ASR) represent a potential energy resource if they can be properly and biologically converted to methane.     

农业生态环境质量综合评价指标体系构建及适宜度分析

通过构建宝泉岭垦区农业生态环境质量评价指标体系,共4层28个指标,采用层次分析法为评价指标赋权重,为垦区农业现代化发展提供有力保障.     

干旱灾害的识别途径

干旱和洪水一样，都是对人类及其社会危害极大的自然灾害，但相对洪水灾害来讲，国内外对干旱灾害的研究均很薄弱。针对这种情况，本文系统地归纳总结了干旱灾害的识别方法，以便为干旱灾害的研究和治理提供帮助。     

江苏省农村环境监测现状及“十四五”工作建议

农村生态环境保护是实现乡村振兴不可缺少的一环,是保障农业农村高质量发展的基础。基于"十三五"江苏省农村环境监测体系和2020年全省农村环境质量监测结果,分析了全省农村环境监测现状。指出,江苏省农村环境监测工作存在监测任务较重、基础信息获取难度较大、水环境监测代表性不足、监测指标单一以及对农业面源污染治理成效评估支撑不够等问题;提出,强化部门数据共享与信息整合、完善农村环境例行监测网络、构建农业面源污染监测技术体系、探索特色指标监测研究、加强农村环境监测人才队伍建设等"十四五"江苏省农村环境监测工作建议,以期摸清农业面源污染现状,为全省农村生态环境治理提供技术支撑。     

Opportunities and challenges for Common Agricultural Policy reform to support the European Green Deal

The Common Agricultural Policy (CAP) is the European Union's main instrument for agricultural planning, with a new reform approved for 2023–2027. The CAP intends to align with the European Green Deal (EGD), a set of policy initiatives underpinning sustainable development and climate neutrality in the European Union (EU), but several flaws cast doubts about the compatibility of the objectives of these 2 policies. We reviewed recent literature on the potential of CAP environmental objectives for integration with the EGD: protection of biodiversity, climate change mitigation and adaptation, and sustainable management of natural resources. The CAP lacks appropriate planning measures, furthering instead risks to biodiversity and ecosystem services driven by landscape and biotic homogenization. Funding allocation mechanisms are not tailored to mitigate agricultural emissions, decreasing the efficiency of climate mitigation actions. The legislation subsidies farmers making extensive use of synthetic inputs without adequately supporting organic production, hindering the transition toward sustainable practices. We recommend proper control mechanisms be introduced in CAP Strategic Plans from each member state to ensure the EU is set on a sustainable production and consumption path. These include proportional assignment of funds to each CAP objective, quantitative targets to set goals and evidence-based interventions, and relevant indicators to facilitate effective monitoring of environmental performance. Both the CAP and the EGD should maintain ambitious environmental commitments in the face of crisis to avoid further degradation of the natural resources on which production systems stand.     

Mitigation of two pyrethroid insecticides in a Mississippi Delta constructed wetland

Constructed wetlands are a suggested best management practice to help mitigate agricultural runoff before entering receiving aquatic ecosystems. A constructed wetland system (180 m × 30 m), comprising a sediment retention basin and two treatment cells, was used to determine the fate and transport of simulated runoff containing the pyrethroid insecticides lambda-cyhalothrin and cyfluthrin, as well as suspended sediment. Wetland water, sediment, and plant samples were collected spatially and temporally over 55 d. Results showed 49 and 76% of the study's measured lambda-cyhalothrin and cyfluthrin masses were associated with vegetation, respectively. Based on conservative effects concentrations for invertebrates and regression analyses of maximum observed wetland aqueous concentrations, a wetland length of 215 m × 30 m width would be required to adequately mitigate 1% pesticide runoff from a 14 ha contributing area. Results of this experiment can be used to model future design specifications for constructed wetland mitigation of pyrethroid insecticides.     

Agricultural policies and the emergence of cotton as the dominant crop in northern Côte d'Ivoire: Historical overview and current outlook

In most of sub‐Saharan Africa, where the agricultural sector experiences dismal performance and is characterized by a gloomy picture, the cotton sub‐sector in Côte d’Ivoire is often mentioned as a “success story” given the spectacular rise in the quantity of cotton production and the profile of the crop within the farming system. What are the historical and political antecedents of the development of cotton and the factors responsible for the feat accomplished in the midst of general failures in the same continent? To what extent can cotton be regarded as a “success story” and, what lessons can be drawn for agricultural development strategies based on the Ivorian case study? This paper traces the historical and socio‐political background of cotton development in Côte d’Ivoire and identifies key policy and institutional interventions that have influenced the rise of cotton production and its emergence as the dominant crop in the farming systems of the country. Four stages in Ivorian cotton development are identified: planning, take off, crisis and the renaissance phases. The study demonstrates how a combination of good planning, technological advancement and appropriate policy and institutional conditions have contributed significantly to the rise of cotton production and its influence on the agricultural economy of northern Côte d’Ivoire. The study also highlights how the sustainability of agricultural development has been impacted by domestic and international policies and political events over which smallholder farm families have little control, and can at best only respond to. Important questions about cotton development in Côte d'Ivoire are raised that need to be answered before the program can be categorized conclusively as a success story. The study shows that there are no quick fixes to agricultural development in the sub‐region. Rather, good planning and putting the necessary building blocks in place are important prerequisites. It is recommended that agricultural development efforts in the continent take cognizance of the complexity of the sector and address the inter‐relationships that exist among the technical, policy, market and institutional factors that combine individually and collectively to influence African agriculture.     

Inexact rough-interval two-stage stochastic programming for conjunctive water allocation problems

An inexact rough-interval two-stage stochastic programming (IRTSP) method is developed for conjunctive water allocation problems. Rough intervals (RIs), as a particular case of rough sets, are introduced into the modeling framework to tackle dual-layer information provided by decision makers. Through embeding upper and lower approximation intervals, rough intervals are capable of reflecting complex parameters with the most reliable and possible variation ranges being identified. An interactive solution method is also derived. A conjunctive water-allocation system is then structured for characterizing the proposed model. Solutions indicate a detailed optimal allocation scheme with a rough-interval form; a total of [[1048.83, 2078.29]:[1482.26, 2020.60]] would be obtained under the pre-regulated inputs. Comparisons of the proposed model to a conventional and an interval two-stage stochastic programming model are also conducted. The results indicate that the optimal objective function values of TSP and ITSP always fall into the range of , while they are sometimes out of the range of ; the optimal solutions of decision variables also present this feature. This implies the reliability of IRTSP in handling conjunctive water allocation problems.     

Landscape Planning for Agricultural Non–Point Source Pollution Reduction. II. Balancing Watershed Size,Number of Watersheds,and Implementation Effort

Agricultural non–point source (NPS) pollution poses a severe threat to water quality and aquatic ecosystems. In response, tremendous efforts have been directed toward reducing these pollution inputs by implementing agricultural conservation practices. Although conservation practices reduce pollution inputs from individual fields, scaling pollution control benefits up to the watershed level (i.e., improvements in stream water quality) has been a difficult challenge. This difficulty highlights the need for NPS reduction programs that focus efforts within target watersheds and at specific locations within target watersheds, with the ultimate goal of improving stream water quality. Fundamental program design features for NPS control programs—i.e., number of watersheds in the program, total watershed area, and level of effort expended within watersheds—have not been considered in any sort of formal analysis. Here, we present an optimization model that explores the programmatic and environmental trade-offs between these design choices. Across a series of annual program budgets ranging from $2 to $200 million, the optimal number of watersheds ranged from 3 to 27; optimal watershed area ranged from 29 to 214 km²; and optimal expenditure ranged from $21,000 to $35,000/km². The optimal program configuration was highly dependent on total program budget. Based on our general findings, we delineated hydrologically complete and spatially independent watersheds ranging in area from 20 to 100 km². These watersheds are designed to serve as implementation units for a targeted NPS pollution control program currently being developed in Wisconsin.     

碱性催化剂对农业废物液化产生生物油和气体的影响

采用热化学处理法对农业废物玉米秸秆和苹果渣进行处理,3种碱性物质Na2CO3、K2CO3和KOH作为催化剂,都能不同程度提高液化生物油收率、减少固体残渣收率.但碱性催化剂会降低气体收率,因而不适合作为以获得气体产物为目的的生物质气化试验的催化剂.就增加液化生物油收率方面而言,Na2CO3的催化效果最好,KOH催化效果次之,K2CO3的催化效果最差.