Policy and technological constraints to implementation of greenhouse gas mitigation options in agriculture

A recent assessment of agricultural greenhouse gas (GHG) emissions has demonstrated significant potential for mitigation, but suggests that the full mitigation will not be realized due to significant barriers to implementation. In this paper, we explore the constraints and barriers to implementation important for GHG mitigation in agriculture. We also examine how climate and non-climate policy in different regions of the world has affected agricultural GHG emissions in the recent past, and how it may affect emissions and mitigation implementation in the future. We examine the links between mitigation and adaptation and drives for sustainable development and the potential for agricultural GHG mitigation in the future.We describe how some countries have initiated climate and non-climate policies believed to have direct effects or synergistic effects on mitigating GHG emissions from agriculture. Global sharing of innovative technologies for efficient use of land resources and agricultural chemicals, to eliminate poverty and malnutrition, will significantly mitigate GHG emissions from agriculture.Previous studies have shown that as less than 30% of the total biophysical potential for agricultural GHG mitigation might be achieved by 2030, due to price- and non-price-related barriers to implementation. The challenge for successful agricultural GHG mitigation will be to remove these barriers by implementing creative policies. Identifying policies that provide benefits for climate, as well as for aspects of economic, social and environmental sustainability, will be critical for ensuring that effective GHG mitigation options are widely implemented in the future.     

A Functional Land Management conceptual framework under soil drainage and land use scenarios

Agricultural soils offer multiple soil functions, which contribute to a range of ecosystem services, and the demand for the primary production function is expected to increase with a growing world population. Other key functions on agricultural land have been identified as water purification, carbon sequestration, habitat biodiversity and nutrient cycling, which all need to be considered for sustainable intensification. All soils perform all functions simultaneously, but the variation in the capacity of soils to supply these functions is reviewed in terms of defined land use types (arable, bio-energy, broadleaf forest, coniferous forest, managed grassland, other grassland and Natura 2000) and extended to include the influence of soil drainage characteristics (well, moderately/imperfect, poor and peat). This latter consideration is particularly important in the European Atlantic pedo-climatic zone; the spatial scale of this review. This review develops a conceptual framework on the multi-functional capacity of soils, termed Functional Land Management, to facilitate the effective design and assessment of agri-environmental policies. A final functional soil matrix is presented as an approach to show the consequential changes to the capacity of the five soil functions associated with land use change on soils with contrasting drainage characteristics. Where policy prioritises the enhancement of particular functions, the matrix indicates the potential trade-offs for individual functions or the overall impact on the multi-functional capacity of soil. The conceptual framework is also applied by land use area in a case study, using the Republic of Ireland as an example, to show how the principle of multi-functional land use planning can be readily implemented.     

Leaching of nitrogen in Swedish agriculture — a historical perspective

There is a need to examine long-term changes in nitrogen leaching from arable soils. The purpose of this study was to analyse variations in specific leaching rates (kg ha⁻¹ per year) and gross load (Mg per year) of N from arable land to watercourses in Sweden from a historical perspective. The start of the study was set to 1865 because information on crop distribution, yield and livestock has been compiled yearly since then. The SOIL/SOILN model was used to calculate nitrogen leaching. Calculations were done for cereals, grass and bare fallow for three different soil types in nine agricultural regions covering a range of climatic conditions. Results indicate that both specific leaching rates and gross load of nitrogen in the middle of 19th century were approximately the same as they are today for the whole of south and central Sweden. Three main explanations for this were (1) large areas of bare fallow typical for the farming practice at the time; (2) enhanced mineralisation from newly cultivated land; and (3) low yield . From 1865, i.e. the start of the calculations, N leaching rates decreased and were at their lowest around 1930. During the same period, gross load was also at its lowest despite the fact that the acreage of arable land was at its most extensive. After 1930, average leaching increased by 60% and gross load by 30%, both reaching a peak in the mid-1970s to be followed by a declining trend. The greatest increase in leaching was in regions where the increase in animal density was largest and these regions were also those where the natural conditions for leaching such as mild winters and coarse-textured soils were found. Extensive draining projects occurred during the period of investigation, in particular an intensive exploitation of lakes and wetlands. This caused a substantial drop in nitrogen retention and the probable increase in net load to the sea might thus have been more affected by this decrease in retention than the actual increase in gross load.     

Socio-economic factors in soil erosion and conservation

Farmer decisions with regard to production and land use are strongly influenced by socio-economic factors. In the developed world, the role of agricultural subsidies, quotas and guaranteed prices is especially important. In the past there have been many examples of economic signals which led to unfortunate and unforeseen environmental consequences (‘perverse subsidies’), including soil erosion. The problems were neglected because of an emphasis on increases in productivity and the fact that many of the costs were hidden or were external to the farm and were borne by society. In recent years ‘agri-environmental measures’ have begun to reverse the trend towards environmental degradation.     

Environmental cross-compliance mitigates nitrogen and phosphorus pollution from Swiss agriculture

In 1993 the Swiss agricultural policy was revised with – amongst other goals – the objective of improving the environmental performance of agriculture. A voluntary agri-environmental scheme to promote integrated production (IP) was introduced. In 1999 the IP standards were integrated in cross compliance requirements and termed Proof of Ecological Performance (PEP). We evaluated the effectiveness of this policy in terms of reducing diffuse nitrogen (N) and phosphorus (P) pollution of ground and surface water. We combined monitoring schemes covering the reference period from before the introduction of IP/PEP (1990–1992) with the evaluation of cause/effect relationships in selected case-study areas. The evaluation showed an overall reduction of diffuse N and P pollution from agriculture even though some goals were not reached. Nitrate leaching declined, but only a 3–4 mg L⁻¹ reduction was observed rather than the intended decrease of 5 mg L⁻¹. The P pollution of surface waters from agriculture decreased by only 10–30% instead of 50%. The intended reduction of the nitrogen surplus of Swiss agriculture by 33% was not attained, but the P surplus of Swiss agriculture was more than halved. IP/PEP practices that improved N and P management included reduced N and P fertiliser inputs and pig and poultry feedstuffs with reduced N and P contents, both of which are a consequence of the requirement of equilibrated farm nutrient balances, as well as increased use of cover cropping and of conservation tillage systems.     

Adaptation of Russian agriculture to climatic variability: The role of federal and provincial policies

This paper draws on the example of Tyumen Province, a federal subject of the Russian Federation, to explore the role that policies play in hindering agricultural producers’ adaptation to climate change. Its objective is to contribute to a better understanding of maladaptation at the policy level. The discourse analysis method is used to explain perceptions of climate variability in Tyumen Province and its impact on agriculture. The document analysis method is used to assess agricultural policy in Tyumen Province and its implications for producers’ adaptation to climate change. The results suggest that although agricultural producers and policymakers are acutely aware both of climate variability and the resulting loss of agricultural output, provincial agricultural policy generally fails to encourage better adaptation by agricultural producers or to support their greater economic security. Instead, it primarily focuses on meeting food production targets and thus limits the producers’ own independent moves towards adaptation. The phenomenon of maladaptation at the policy level is discussed in consideration of the general public’s and the authorities’ awareness of climate change and climate variability, and the role of science in shaping this awareness.     

农业化学投入与农业经济增长脱钩关系研究——基于华东6省1市数据

论文选取华东6省1市2001—2014年的数据,分析了农业面源污染控制背景下的农业化学与农业经济增长的Tapio脱钩关系,并通过LMDI分解将农业化学投入增长的影响因素归结为规模效应、耕地效应和效率效应,最后对2014年华东6省1市农业化学效率状况进行K-means聚类。结果表明：农业面源污染控制背景下,农业化学与农业经济增长呈现出从扩张性负脱钩到相对脱钩,再到绝对脱钩的转变;农业化学投入物量的增加主要来自于耕地效应的作用,效率效应可以减缓农业化学投入物量的增长,规模效应的作用不明显;从空间格局的聚类结果上看,上海、江苏、浙江、福建、江西和山东的农业经济增长对农业化学品生产资料依赖程度较低,安徽省的依赖程度较高。总之,农业经济可以在农业化学化控制背景下得到持续增长,农业面源污染要得到进一步的控制,需要在采用多种农业增效手段、提高农业化学投入利用效率和采取差异化的区域农业化学投入减量控制政策着手。     

Methodological considerations for nitrogen policies in the Netherlands including a new role for research

The Netherlands has attempted to follow EU guidelines in developing national policies to reduce pollution of groundwater by nitrates originating from (over) fertilized agricultural land. The EU has not been satisfied with these policies and this is resulting in legal conflicts. National policies have focused on nitrogen budgeting and on fertilization rates, over-simplifying the crucial role of soils during the leaching of nitrates to groundwater. As an alternative, a dynamic approach using simulation modeling is introduced as is illustrated for a study area in the Netherlands. A number of considerations for future policy directions are suggested, including requirements for research: (i) promotion of research aimed at improving and maintaining nutrient use efficiency at farm level; (ii) promotion of joint learning experiences between farmers and researchers, where farmers’ organizations could act as “research consortia”; (iii) emphasis on site and time specific management (precision agriculture) in policy development, and provision of site-specific advice via modern information and communication technologies; (iv) clearer guidelines for groundwater monitoring procedures, including additional monitoring at greater depths and consideration of groundwater quality from an appropriate regional perspective; (v) groundwater monitoring should take place at locations selected according to specific hydro-geological characteristics, rather than being executed at random and (vi) clear goals that are defined within existing and future policies at EU and international level, should allow for regional differentiation in indicators; these being the outcome of negotiations between farmers or their representatives, policy makers and researchers.     

本溪县农业面源污染现状及防治对策

通过科学的调研数据,重点分析了本溪县农药、化肥和农膜造成的环境污染。调查结果表明,本溪县农药、化肥和农膜的大量施用,虽然可以提高农作物的产量,但也会对人、土地、水体和生物等产生诸多不利的影响,从而提出相应的治理对策。建议发展生态农业,加强监督管理,研究制定相应的污染控制政策与措施。     

西藏土地资源特点及其合理开发

西藏土地辽阔，但其宜农土地少而分布集中；宜牧土地数量大，但质量差异大；宜林土地质高量大；高寒干旱及难利用土地较广。这些特点决定了西藏农林牧生产的结构、规模和布局。目前土地开发水平低、商品性生产落后，部分土地有所退化，经济与生态效益均不高。因此，今后应加强科学管理、增加投入，深度开发与保护农林牧各类土地资源。提高现有耕地的单产水平；改良草地与建设人工草地，采育结合；保护森林等乃是促进西藏农业经济发展、改善农业生产条件与生态环境的战略方针和有效对策。     

现阶段我国耕地利用集约度变化及其政策启示

近年来,随着社会经济的快速发展和市场经济的不断完善,我国耕地利用中,农户利益最大化的个体追求逐步由耕地产出最大化向劳动力效益最大化方向发展,粮食生产对于农户的重要性在下降,导致我国粮食生产中耕地、资本和劳动力投入在1998年后出现下降趋势,北京、天津、上海、浙江、福建、江西、湖北、广东等省(市)区甚至出现耕地利用集约度总体下降的情况。耕地利用集约度的这一变化对我国粮食安全将产生深远的影响。文章在分析上述情况后认为,为实现我国粮食安全的国家目标,需要在耕地保护政策的基础上,进一步采取政策措施提高粮食生产的规模效益,以缓解粮食安全的国家目标与个体利益最大化的农户目标之间的冲突。     

农田保护经济补偿政策实施异质效应——基于DID模型的动态估计

论文以国内率先试点探索农田保护经济补偿政策的创新实践地区——成都和苏州为典型实证,基于2012和2015年两期农户动态跟踪调研数据,运用DID模型测量农田保护经济补偿政策实施异质效应及影响因素。结果表明：1）农田保护经济补偿政策的持续实施显著增加实践地区农民的政策满意度,激励农民参与农地流转,但对提升农民参与农田保护性耕作措施的作用较小。2）农田保护经济补偿政策实施成效具有显著异质性。2008年开始试点养老保障与农业补偿相结合的耕地保护基金政策的成都市,农户政策满意度的上升幅度相对较大。乡镇经济发达、长三角地区经济发展带重镇的苏州市,农户家庭生计多元,户均非农业收入占比达82.12%,较成都农户高2.66%,农地生计依赖较弱,补偿政策明显促进该区域农户参与农地流转,但农户农田保护积极性值却大幅下降。3）受访者的年龄、受教育水平、农田保护及功能认知、对农田保护政策关注程度、农业收入占比、家庭劳动力比例、调研村庄经济水平及受访村庄与最近城镇距离均会显著影响农田保护经济补偿政策实施成效。     

对中国发展农业循环经济的思考

发展农业循环经济是实现农业清洁生产,农业资源可持续利用的有效手段,也是解决现代农业困境的必然选择。中国现阶段新型的农业循环经济发展模式包括白色农业发展模式,精准农业发展模式,有机农业发展模式。结合这些农业循环经济发展模式中国需要通过采取改革现行的财政预算管理制度,完善相关政策法规体系,培养农业经营者的素质,提高农业经营的组织化程度以及增强社会公众的环保意识这一系列措施促进农业循环经济的发展。     

中国亚热带东部丘陵山区农业自然资源开发策略

我国亚热带东部丘陵山区农业生产条件优越,但由于农业生产主要局限在耕地上,沟谷农业限制着整个农业的发展,一些农村仍处于贫困状态。本文通过对农业生产条件的综合研究和对沟谷农业的进一步分析,提出了充分利用自然资源,使整个山区致富的根本出路是:摆脱沟谷农业的束缚,发展生态农业生产和商品经济,壮大农村实力,农业生产走上良性循环的道路。     

农用地集约利用评价的新模型研究

作为农业大国,中国面临着农用地利用效率低下,耕地数量锐减的现状。如何缓解人地关系、 提高农用地集约利用效率是目前中国解决农用地问题的迫切需要。因此,开展农用地集约利用评价具有十分重大的意义。论文以陕西省为例,提出基于动态模糊神经网络的农用地集约利用评价模型,以克服传统方法学习过程慢,易造成规则灾难、 过度拟合等问题。为了提高评价的准确性,采用定性与定量相结合的方法挑选评价指标体系,剔除冗余程度高的评价指标:耕地平衡指数和单位面积劳动力人数。对动态模糊神经网络模型进行训练和测试,模型收敛结果良好,误差均不超过3×10^-16。为了便于分析评价结果,采用K-means方法将评价分值聚为四类,并与陕西省农用地集约度的空间分异(陕北、 关中、 陕南)实际情况对比。结果表明,采用新模型的评价结果与陕西省各地级市的实际情况相符,杨凌示范区的集约程度最高。最后,通过逐步回归分析得出,农用地集约度与农民人均纯收入呈显著正相关,其相关系数为0.74,高于人均GDP、 城市化水平,农民人均纯收入是影响农用地集约度的主要因素。     

水土资源匹配视角下中国省域农产品供需平衡分析及其政策启示

粮食安全关系到中国稳定与发展和国际贸易秩序。以省级行政区为基本单位,基于2016—2018年各省份常住人口、农产品消费量、农业数据及相关参数,采用生态足迹和水足迹评价方法,在只考虑食用和再生产消费且不考虑地区耕地质量差异的条件下,核算各省份农产品自给的水土资源需求,评价中国省域水土资源承载力状态。结果显示：（1）中国现有耕地资源总量可满足自身耕地总需求（前者是后者1.81倍）,但省际差异大,东部沿海省市耕地不足。（2）农业可用水资源总量亦可满足农业可持续生产需求,但区域严重不平衡,华北平原与宁夏水资源赤字严重,而青藏高原地区、长江以南省份农业可用水资源丰富。（3）水土资源空间不匹配制约了中国农业的粮食生产潜力,不考虑环境净化用水,水土资源匹配状态可满足全国粮食自给需求;但考虑环境净化用水,中国粮食难以实现自给,承载力赤字达33715.50万人。以资源环境可持续为导向,未来中国应从农业生产布局优化、农业结构调整、农业科技、产业与人口转移、农产品进口和农业国际合作等方面着手,解决中国农产品需求问题。     

基于经济发展阶段理论的土地利用变化研究——以广西江州区为例

土地利用在不同的经济发展阶段表现出不同特点。广西江州区属于我国西部经济欠发达地区,经济发展正处于工业化初期的起步阶段,土地利用变化特点主要表现为:以农业生产用地和生态用地竞争为主,耕地变化是土地利用变化的主要内容;建设用地低效、缓慢增长,农村居民点增长面积占较大比重;人均农村居民点面积逐渐增加。以1978-2002年的统计数据为基础,用主成分分析和回归分析相结合,对耕地面积变化的驱动力进行了研究,结果表明:人口增长、经济发展和土地管理使得耕地面积不断增长,收入和消费的提高以及农业产业结构调整导致耕地面积减少。发达地区的发展历程表明,经济高速发展必然引起农地快速非农化,江州区在土地利用中,必须注意节约用地,保护耕地,减少土地资源浪费,防止环境污染,实现区域土地的可持续利用。     

Adaptation to climate change: changes in farmland use and stocking rate in the U.S.

This paper examines possible adaptations to climate change in terms of pasture and crop land use and stocking rate in the United States (U.S.). Using Agricultural Census and climate data in a statistical model, we find that as temperature and precipitation increases agricultural commodity producers respond by reducing crop land and increasing pasture land. In addition, cattle stocking rate decreases as the summer Temperature-humidity Index (THI) increases and summer precipitation decreases. Using the statistical model with climate data from four General Circulation Models (GCMs), we project that land use shifts from cropping to grazing and the stocking rate declines, and these adaptations are more pronounced in the central and the southeast regions of the U.S. Controlling for other farm production variables, crop land decreases by 6 % and pasture land increases by 33 % from the baseline. Correspondingly, the associated economic impact due to adaptation is around ?14 and 29 million dollars to crop producers and pasture producers by the end of this century, respectively. The national and regional results have implications for farm programs and subsidy policies.     

北京农业地域功能空间分异及影响因素

北京减量提质发展背景下,农业地域功能主要体现在优质农产品生产、生态保护、高端休闲娱乐供给、新业态示范、产业链拓展与融合以及就业收入拉动等方面。以184个街道、乡镇为基本研究地域单元,测算了北京农业地域功能并剖析了空间分异特征。研究发现：北京农业地域功能空间分异与城市空间开发结构密切相关,总体上表现为自城乡结合部核心区、拓展区到远郊区呈圈层递增态势;城乡结合部拓展区农业地域功能衰退趋势显著,对城市空间开发的约束变弱;远郊区农产品供给、生态保护和就业安置等基本和传统功能较强而产业融合、新业态等高级与现代功能偏低,农业地域功能仍有较大提升空间。通过OLS基本回归和分位数回归发现,土地因素是影响北京农业地域功能的关键因素,其中区位因素决定农用地规模进而影响农业地域功能,房价因素通过加速农用地流转对功能最弱地区的农业地域功能具有明显抑制作用。非农产业对农业地域功能具有促进而非挤压替代作用。     

Effects of policy measures implemented in Denmark on nitrogen pollution of the aquatic environment

Since 1985, seven national Action Plans (AP) have been implemented in Denmark to reduce nitrogen discharges from point sources and nitrogen losses from agriculture. The instruments applied include regulations on point source discharges from waste water treatment plants, area-related measures, e.g. reestablishment of wetlands and afforestation and nutrient-related measures, e.g. mandatory fertilizer plans and improved utilization of nitrogen in manure. A national monitoring programme was launched in 1988 to monitor trends in nitrogen losses from point sources and diffuse agricultural sources. Four national indicators were defined: nitrogen discharges from point sources, nitrogen surplus in agriculture, nitrogen leaching from agricultural land and nitrogen concentrations and loads in surface waters. Since the introduction of mitigation programmes, discharges of nitrogen from point sources have been reduced by 74% (1989–2003), nitrogen surplus by 31% (1990–2003), and model calculated nitrogen leaching from the root zone on agricultural land by 33% (1989–2002). Trend analysis of total nitrogen concentrations and loads in 86 streams draining smaller agricultural catchments shows an average respective reduction of 29 and 32% (1989–2004). The change in model calculated nitrogen leaching varies between 28 and 44% as calculated for catchments within eight geo-regions covering most of Denmark. The average trend calculated for nitrogen concentrations measured in the same streams and geo-regions shows a reduction in total nitrogen concentration between 8 and 45%. The instruments and measures adopted in Denmark to regulate nitrogen losses from different pressures have therefore proven successful. The impact of the regulations are, however, not equally high in all geo-regions which is possibly related to delays in travel time in groundwater. Until now, the regulation has been performed on a national scale. A more regional or local approach is believed to be necessary in future to meet the demands of the EU Water Framework Directive.