四川省重点生态功能区有机农业生产效率研究——基于三阶段DEA模型的实证分析

[目的]有机农业为我国农业绿色发展起到良好的带动作用,但我国有机农业发展中,西部贫困地区较为滞后。针对西部贫困地区有机农业生产效率进行定量分析,揭示影响有机农业生产效率的主要因素,旨在提高该地区有机农业生产效率,丰富区域视角下的有机农业生产研究。[方法]采用三阶段DEA模型对2014年四川省重点生态功能区有机农业生产效率进行量化分析,识别环境变量对有机农业生产效率的影响。[结果]环境因素和随机误差对四川省重点生态功能区有机农业生产效率产生了显著的影响。环境因素中,农民人均纯收入的增加有利于促使农机、耕地等资源的有效利用,但同时也导致化肥投入冗余增加;城镇化率的提高会降低耕地、劳动力、化肥、农药等使用效率,从而对有机农业生产效率产生不利影响;财政支出占GDP比重的增加有利于提高农机使用效率,但同时也导致化肥和农药投入冗余增加;粮食播种面积占耕地面积比重对有机农业生产效率产生了不利影响。剔除环境因素和随机误差的影响后,四川省重点生态功能区各县平均技术效率和规模效率有所下降,纯技术效率则略有提升。基于纯技术效率和规模效率,四川省重点生态功能区各县有机农业生产效率可分为"双高型""高低型""低高型"和"双低型"等4种类型。[结论]三阶段DEA模型有效剔除了环境因素和随机误差对有机农业生产效率的影响,估计的效率值更真实地反映了四川省重点生态功能区有机农业生产效率水平。针对四川省重点生态功能区各县有机农业生产效率的不同特征,应结合地方实际,通过扩大要素投入规模或改进要素配置效率和使用效率,提高有机农业生产效率。     

山西省农业温室气体排放探析

[目的]关注农业温室气体的排放,有利于农业生态文明建设。[方法]文章以山西省农业作为研究对象,运用实地调研和文献查阅法对山西省农业现状进行了分析、并运用农业系统的碳排放估算方法对2006—2015年的农业投入要素和畜禽养殖数量产生的碳排放进行了测算。[结果](1)山西省农业碳排放量呈现先上升后趋于稳定的状态,近年来农业碳排放总量维持在220万t左右,农业投入要素产生的碳排放比重从高到低依次为化肥、农膜、柴油、农药、灌溉和翻耕;(2)种植业碳排放最高的运城市约为36.359万t,排放最低的阳泉市为2.782万t,运城市是阳泉市的13倍;(3)畜禽养殖数量决定畜禽碳排放量的数值, 2015年山西省养殖业CH_4排放量最大的是晋中市,排放量达到4 260.56t,养殖业CH_4排放量最小的是阳泉市,排放量为387.51t,晋中市的排放量是阳泉市的11倍;(4)受自然资源、农业政策和当地经济发展状况的影响,山西省各地市的碳排放分布不均匀。[结论]建议农户采用低碳农业生产方式;政府鼓励适当的农业规模化生产、鼓励低碳生产技术的研发和使用,兼顾经济、生态和社会三方效益,合理发展低碳农业。     

Evolution and future direction of intensified agriculture in the central mid-hills of Nepal

Nepalese mid-hill farmers have shifted from a subsistence-based farming system to an intensified farming system. This paper attempts to describe the evolution of the process of agricultural intensification in the mid-hill region by examining external drivers, trends in fertilizer use, landholding, cropping patterns, irrigation and labour use in the years 1989, 1999 and 2009. Data were obtained by means of structured interviews, focus group discussions, key informant interviews and field observations. The study revealed that modern technology and the involvement of NGOs have facilitated the agricultural intensification process in three ways: (i) by providing access to technology without any financial cost to the farmer, (ii) by increasing the variety and number of crops and encouraging farmers to discontinue crops that had pest problems and (iii) by maximizing the use of chemical fertilizers to increase production. Results showed a significant increase in the application of urea and diammonium phosphate (DAP) and a decrease in the application of farm yard manure (FYM) and muriate of potash from 1989 to 2009 (p < 0.001). The average landholding of 0.76ha in 1989 was reduced to 0.63ha by 2009. The number of crops (rice, maize or millet) cultivated per year increased to at least three crops with the introduction of potatoes and spring rice; however, some crops such as sugarcane and tobacco were not continued as a result of pest problems. Increased nitrogen input could lead to increased N₂O emissions; therefore, a better understanding of nitrogen fertilization and quantification of N₂O emissions from intensified agriculture is urgently needed to assess the possible environmental impact of input intensification.     

基于生态系统服务改进的中国各地农业生态效率研究

[目的]为提高全国农业资源利用率,推动建立资源节约型与环境友好型的可持续"两型农业",对中国农业生态效率展开研究发现,农田生态系统服务是农业生产的重要产出,但在当前生态效率研究中未得到充分体现。文章通过量化农田生态系统服务价值,有利于权衡农产品供需关系,更好以农田生态系统给人类社会带来的福利为目标来开展农业生产。[方法]文章将生态系统服务价值作为期望产出之一,将全国划分为东部地区、东北地区、中部地区和西部地区的4个农业效率研究区域。运用非期望产出数据包络分析方法,计算2014年中国30个省(市、自治区)的农业生态效率,并分析其主要影响因素。[结果](1)中国农业生态效率整体水平良好,平均值为0.945,在空间上表现为东部东北西部中部的空间分布格局。(2)影响全国农业生态效率的关键因素为土地投入、机械投入、化肥投入和水资源投入。农业生态系统服务指标与农业生态效率呈正向相关。土地、农药、劳动力、机械、水资源、化肥、农膜和能源投入、农业产值及碳排放均与之呈负向相关。其中农药投入是最为显著的抑制因子,控制农药投入是提升全国农业效率核心因素。(3)中国农业生态效率空间分异格局是多层影响因素叠加而成,中国农业生态效率损失的原因主要在于资源要素消耗的过量与农业碳排放过多。[结论]中国农业生态效率整体上发展较好,但各省市的农业生态效率水平存在较大差异,仍有上升的空间。从投入产出冗余角度来看,目前中国农业生态效率损失的原因主要在于资源要素消耗的过量与农业碳排放过多。在发展中着重加大区域对农业土地的开发投入、推广机械科学技术、减少化肥等污染物投入与提高水资源的利用效率,发展用水技术,保障农业的可持续发展。     

基于种植结构调整视角的化肥减施对策研究

[目的]化肥过量使用是导致农业面源污染和农产品产地环境风险的重要因素。虽然已提前实现化肥使用量"零增长"目标,但"后零增长"时代,探寻巩固和推进化肥减施的有效对策仍是当务之急。[方法]文章运用灰色关联分析法与比较分析法,定量分析不同作物种植面积调整对化肥使用量的影响。[结果]化肥用量变化与果蔬类作物种植面积的调整密切相关。近年各省份化肥用量的变化趋势,也佐证了耗肥量大的果蔬类作物种植面积的消长,是助推我国化肥使用量增减变动的重要因素。[结论]种植业结构调整策略将成为控制化肥用量的重要途径,调减非优势区作物种植面积,构建生态友好型耕作制度,在生态脆弱地区开展休耕,综合运用国际农业资源和产品市场,保障短缺农产品供给等种植业结构优化措施,是推动化肥减量直接而有效的方式。同时,应注重转变传统施肥方式,推广化肥减施增效技术,强化绿色发展政策支持与引导,巩固化肥"零增长"成效。     

The attitude of grassland farmers towards nature conservation and agri-environment measures—A survey-based analysis

Grasslands have a multi-layer protection function for nature, biodiversity and climate. These functions can be fostered by an adapted management on grassland farms. Promoting nature protection alongside agricultural production is an aim of European agricultural policy. However, a number of studies indicate that existing Agri-environment measures (AEM) are not as effective as assumed, mainly because they are not sufficiently used by farmers. We investigated the view of grassland farmers on nature conservation and on existing AEM in four distinct regions on a west to east gradient in the North German Plain. We conducted a survey on 82 grassland farms inquiring basic farm data and asking questions on general agricultural issues and nature protection. The results indicate that the majority of all respondents is generally interested in nature conservation and believes it to be of concern for every farmer. In contrast, only a minority of grassland farmers is using the existing AEM to the full extend on their own farm. By applying the concept of farming styles, we classified farmers into four groups, namely Traditionalist, Idealist, Modernist, and Yield Optimizer. These farming styles groups differ in farm and management parameters, general attitudes towards agricultural issues, farming objectives and economic success. We found that in our survey the farming styles groups differ in their attitude towards nature conservation. However, they do not differ in the adoption of AEM and have different reasons for not taking part. We state that for a better implementation of AEM into agricultural practice a better communication, which is adapted to the different ways that farmers manage their farm and think and feel, is needed. Consequently, AEM need to be revised as well.     

长江中下游城市群农业面源污染氮排放评价及调控

基于清单分析法和排污系数法,对长江中下游城市群农业面源污染氮排放现状进行了评价,并运用灵敏度分析和情景分析方法,模拟和比较了不同调控方案对区域未来氮排放变化的影响。研究结果表明,2011年长江中下游城市群4种污染源向水环境排放的氮总量共计128.27万t,其中,农业种植和畜禽养殖的排放比例分别为58.92%和33.53%,是该区农业面源污染的主要氮污染源。如果不加大对面源污染的治理力度,2011~2020年和2020~2030年长江中下游城市群农业面源污染氮排放量将分别增加16.29%和18.78%;如果采取相关减排措施,2020年和2030年4个城市群的农业面源污染氮排放量将分别比2011年削减15%和25%,并有利于实现区域农村经济增长与环境健康发展的双重目标。建议今后全区农业面源污染氮排放调控的重点在于逐步削减肥料投入、合理优化用肥结构、控制畜禽养殖规模扩张以及促进专业化养殖畜禽废物循环利用等,主要控制地区包括武汉城市圈内的潜江市、孝感市、黄冈市和鄂州市,长株潭城市群内的长沙市和湘潭市,鄱阳湖生态经济区内的南昌市和鹰潭市,以及皖江城市带内的六安市和合肥市。     

农户减少化肥用量和采用有机肥的意愿研究——基于洱海流域上游面源污染防控的视角

[目的]过量施用化肥导致水体富营养化是造成洱海流域上游面源污染的主要原因之一,调查分析农户减少化肥用量和采用有机肥的意愿有助于了解其调整施肥结构的行为。当前研究忽视了农户减少化肥施用强度和采用有机肥的意愿间的替代性,未能开展联立研究。[方法]基于洱海流域上游397个水稻种植户的问卷调查数据,通过Bivariate-Probit模型对农户减少化肥用量和采用有机肥两种意愿进行分析。[结果]年龄负向影响农户减少化肥量的意愿,农户对有机肥好处的认知正向影响其减少化肥量的意愿,农户参加农业社会化服务对其减少化肥用量和采用有机肥的意愿均产生正向影响,相比之下,对农户采用有机肥意愿的促进作用更大。[结论]引导农户参加农业社会化服务以及加强宣传和培训,提高农户对有机肥作用的认知可能是加强其减少化肥用量和增加有机肥施用量意愿的有效途径。     

南方水网地区“莲虾共作”立体种养生态农业模式——以湖北省鄂州市峒山村为例

文章以峒山村为例,对"莲虾共作"立体种养生态农业模式的内涵、技术流程、配套技术以及经济、生态和社会效益进行了系统的研究分析。"莲虾共作"模式以4年为一个轮换周期。莲田养虾系统和人工湿地一样具有净化水质、涵养水源,保护农田生物多样性等功能,使系统内物质能量得到高效利用,减少农药和化肥施用,有效遏制农业面源污染,同时产出质优、安全的莲籽、小龙虾等农产品。"莲虾共作"模式平均纯收入可达到5.72万元/hm2,比"稻虾共作"模式纯收入高出1/2以上。最后提了加强"莲虾共作"模式示范推广和编制技术规程的建议。     

Agricultural land-use change during economic reforms in Ghana

Land-use change is driven by many interrelated factors including national policies formulated in response to the forces of globalization. This study integrates remote sensing data with social surveys to identify the role of demographic, technology and market-related variables in cropland expansion during economic reforms in Ghana. Macroeconomic changes increased the commercial orientation of farming as the sources of food supply changed from import to domestic production. However interest rates liberalization increased the use of labor at the expense of fertilizer and other complementary inputs. Demographic variables were more important in explaining cropland change after structural adjustment. Public agricultural support services are required for sustainable market-induced agricultural change in Ghana.     

常州市农业可持续发展现状及其对策

随着农地制度的改革、农业投入和技术创新活动的加强,常州农业现代化建设取得了较快发展,但农用地面积不断减少、农业投入不足、农业产业化发展缓慢及农业生态环境恶化等问题影响和制约了常州的农业可持续发展,针对性地提出了加强农用地和生态环境的保护、调整和优化农业产业结构、重点扶持龙头企业和增加科技投入等措施,以实现常州农业可持续发展。     

Does sustainable intensification of maize production enhance child nutrition? Evidence from rural Tanzania

Food insecurity, child malnutrition, and land degradation remain persistent problems in sub‐Saharan Africa. Agricultural sustainable intensification (SI) has been proposed as a possible solution to simultaneously address these challenges. Yet there is little empirical evidence on if agricultural management practices and inputs that contribute to SI from an environmental standpoint do indeed improve food security or child nutrition. We use three waves of data from the nationally‐representative Tanzania National Panel Survey to analyze the child nutrition effects of rural households’ adoption of farming practices that can contribute to the SI of maize production. We group households into four categories based on their use of three soil fertility management practices on their maize plots: “Nonadoption”; “Intensification” (use of inorganic fertilizer only); “Sustainable” (use of organic fertilizer, maize–legume intercropping, or both); and “SI” (joint use of inorganic fertilizer with organic fertilizer and/or maize–legume intercropping). The results from multinomial endogenous treatment effects models with the Mundlak–Chamberlain device suggest that use of practices in the “SI” category is associated with improvements in children's height‐for‐age and weight‐for‐age z‐scores relative to “Nonadoption,” particularly for children aged 25–59 months. These effects appear to come through improvements in both crop income and productivity.     

Agricultural extension and imperfect supervision in contract farming: evidence from Madagascar

This article tests whether agricultural extension and imperfect supervision—conflated here into the number of visits by a technical assistant—increase productivity in a sample of contract farming arrangements between a processing firm and small agricultural producers in Madagascar. Production functions are estimated which treat the number of visits by a technical assistant as an input and which exploit the variation in the number of visits between the contracted crops grown on a given plot by a specific grower, thereby accounting for district‐, grower‐, and plot‐level unobserved heterogeneity. Results indicate that the elasticity of yield with respect to the number of visits lies between 1.3 and 1.7.     

Using Multi-Criteria Decision Models to Assess the Economic and Environmental Impacts of Farming Decisions in an Agricultural Watershed

This paper reports on the integration of a farm decision model with a watershed biophysical model to evaluate the economic and environmental impacts of farming decisions in an agricultural watershed. A baseline, one uncoordinated and four watershed-level coordinated decision scenarios were evaluated and compared as alternative ways of managing the significant tradeoffs expected when multiple conflict management objectives exist. The four coordinated scenarios outperform the uncoordinated one in terms of economic returns and key environmental impacts. The study's findings contribute to the understanding of biophysical and economic processes in agricultural watersheds.     

The transformation of the Indian agricultural input industry: has it increased agricultural R&D?

Indian agricultural input industries have gone through a major transformation in the last 40 years. State owned firms grew during the Green Revolution and then stagnated or declined. Indian corporations that were protected from foreign competition are now exporters of agricultural tractors and pesticides. Foreign multinational corporations are rapidly increasing their role in the seed, pesticide, and tractor industries. Entry by large Indian firms and multinationals has increased competition in the input industries. Private agribusiness R&D in India grew from $23 million in 1985 to $250 million in 2009 in 2005 US dollars. This is the same time period as a transformation in the agricultural input industry, rapid growth in demand for agricultural inputs, breakthroughs in information technology and biotechnology, and changes in intellectual property rights. An econometric model was used to test whether the transformation of agricultural input industry was a major factor in the growth of R&D expenditure or not. This article analyzes a unique, firm level sales and R&D data set from the seed, pesticide, tractor, and fertilizer industries in 2000–2009. The estimated model indicates that agribusiness firms' R&D expenditures from 2000 to 2009 were positively related to variables associated with industry transformation such as firm size, ownership by multinationals, and declining industry concentration. The model also indicates that strengthening patent policy as well as growth in the size of research‐intensive industries like the seed industry contributed to the growth of agribusiness R&D in India.     

经济新常态下创新驱动型现代低碳农业发展研究*——以成都平原地区为例

[目的]在全球气候变暖,资源枯竭的背景下,发展低碳农业是农业可持续发展的迫切需求。文章通过分别计算种植业、畜牧业、农业生产用具碳排放量得出成都市近年来碳排放情况,为成都平原地区农业低碳经济发展提供研究与实践基础。[方法]选取2004—2015年科技发展财政投入数据与农业碳排放量,运用回归模型验证农业科技投入与农业碳排放量的关系,探究农业科技投入对农业减排的促进作用。[结果](1)成都市的种植业碳排放在40年整体呈下降趋势,主要原因是种植面积的减少;(2)化肥碳排放量在1999—2015年整体呈下降趋势,减排效果较为明显,农业灌溉碳排放量整体平稳下降而减少的势头还未放缓,其在未来仍具有较大的减排潜力;(3)农业机械的碳排放最小也最为稳定, 16年来一直保持在1.6万t左右,碳排放强度也在0.017 t/hm~2上下,可见成都市农业在21世纪初到目前的农业机械使用量基本稳定,对其依赖性较弱,有进一步减排的可能。(4)技术因素对减少农业碳排放具有驱动作用,并且随着技术资金投入的增加,减排工作会进入到"瓶颈",碳排放量减少的速度将逐渐放缓。[结论]通过理论分析与案例研究,发现技术、制度、文化与农业碳排放量的内在逻辑关系,为促进低碳农业发展,应从制度、技术、文化3个方面推动创新。     

超量灌溉对农田耕作区水土肥流失的影响

目前,对山区、丘陵区的水土流失情况及治理措施,已有相对成熟的研究,但对于平原农田耕作区的水、土、肥的流失与治理,则少见有研究资料与科研成果发布。而平原农田耕作区在暴雨或高强度灌水情况下,极易造成土壤水、土、肥的流失。文章针对上述情况,选取具有代表性的沧州枣粮间作地中壤质土作为试验材料,模拟不同降雨强度与施肥量下,土壤经水流冲刷后,观察水、土、肥的流失规律。通过模拟天然降雨过程,对土壤中水、土、肥流失的影响,探索出平原农田耕作区治理水土流失的一般规律,并提出保护地表免受雨滴打击、加大表层土壤贮水量等提高土壤入渗性能的治理措施。     

Peasant household modelling: Farming systems evolution and sustainability in northern Zambia

Chitemene slash-and-burn cultivation continues to be a dominating cropping system in northern Zambia even after the introduction of modern technologies such as hybrid maize and fertilizer. The rationale of farming systems evolution in northern Zambia where labour markets have been absent or highly imperfect, has been analyzed by goal programming based on the theories of Chayanov (1966) and Nakajima (1986). Carrying capacity estimation is incorporated in the models and discussed in relation to the sustainability of land use systems in the area. The major changes in agricultural technologies in northern Zambia during this century has been the introduction of cassava, maize and fertilizer technologies. Cassava has had the most significant impact since the land could support much higher population densities and since the dependence on the chitemene system no longer was critical for the survival of peasants. By switching from finger-millet to cassava as the main staple the peasants could reduce their total labour recquirement to meet their basic food needs by as much as 40%. The results also show that the maize-fertilizer technology has been unable to replace the chitemene system because economic incentives to continue the system exist as long as there is suitable woodland available. Nevertheless, the introduction of the maize-fertilizer technology may have resulted in reduced chitemene cultivation. The rapid expansion of maize production in northern Zambia from the late 70s to the late 80s depended critically on the government policy of equity pricing and input subsidisation. The models predicted that the removal of fertilizer subsidies would result in a dramatic reduction in maize production.     

Mixed farming in Africa: the search for order, the search for sustainability

This paper examines the interest in the development and promotion of mixed farming in sub-Saharan Africa. For over 70 years mixed farming has been a dominant model for agricultural development despite the limited success of many of the programmes which have specifically promoted it. It is suggested that the establishment of mixed farming as a strong development theme is related to its promise to address a range of environmental and social concerns, and in so doing, help create order out of a ‘chaotic’ African countryside. Mixed farming is again being highlighted with the more recent interest in sustainable, environmentally friendly agricultural systems. However, there is considerable evidence that African farmers have adopted a flexible principles-based approach to the use of component technologies commonly associated with the mixed farming model. This must be fully acknowledged, and the seduction of unitary models avoided, if agricultural research is to contribute efficiently to the development of more sustainable farming systems.     

耕地质量禀赋、社会分工对农户化肥减量技术采纳行为的影响——基于鄂豫两省样本农户的实证

目的 促进农户采纳化肥减量技术是保障农产品安全、治理农业污染和推动农业绿色发展的重要举措,文章旨在探究耕地质量禀赋与社会分工对农户采纳化肥减量技术的影响及其内在逻辑。方法 基于湖北和河南两省700户农户的微观调研数据,利用Ordered Probit模型分析了耕地质量禀赋与社会分工对农户化肥减量技术采纳行为的影响。结果 （1）耕地质量禀赋对农户化肥减量技术采纳行为具有显著正向影响,耕地质量禀赋每增加一个单位,化肥减量技术采纳率将提高25%,土壤越肥沃,灌溉条件越便利,通机耕路的耕地,农户越会采纳化肥减量技术。（2）耕地质量禀赋越好,则农户更愿意参与横向分工,促进其采纳化肥减量技术,中介效应为0.062,且纵向分工能明显缓解质量禀赋较差耕地对农户化肥减量技术采纳的负向影响。（3）耕地质量禀赋对小农户采纳化肥减量技术具有显著正向影响,且社会分工增强了耕地质量禀赋对小农户化肥减量技术采纳行为的促进作用,而耕地质量禀赋对大农户化肥减量技术采纳行为没有显著影响。结论 因此,多渠道提升农户耕地条件,全方位推进农业社会分工,对不同规模农户采取差异化的激励和引导策略,均是推广化肥减量技术的有效途径。