供给侧结构性改革推进四川省玉米产业转型发展策略

[目的]随着中国粮食产量的"十二连增",国内农业生产的主要矛盾也逐步由总量不足转向结构性矛盾,其中玉米产业面临的矛盾尤为突出,玉米产业结构调整是我国农业供给侧结构性改革推进中的首要任务。四川既是全国玉米生产的重要省份,也是玉米消费大省,如何推进玉米产业供给侧结构性改革、实现产业转型发展还有待于思考。[方法]文章从供需平衡、供给结构、供给效益和供给效率4个角度分析了四川玉米产业供给侧的特征,同时从要素供给、社会化服务和产业链3个方面分析了影响四川玉米产业发展的制约因素。[结果]四川玉米消费结构呈现多元变化,从口粮消费为主转变为以饲料、工业加工消费为主;草食畜牧业发展迅速,饲用作物需求量增大;农业科技支撑力度明显,玉米育种成就突出。[结论]提出从优化品种结构、推行种养循环、培育新型经营主体、拓展产业链等方面推进四川玉米产业的转型升级。     

Farm demand for quality potato seed in Indonesia

Seed is the one of the most costly components of potato production in developing countries. Since potato is a vegetatively reproduced crop, diseases such as viruses build up and yield declines as tubers are saved from one harvest for use as seed the next season. Replacing farm‐saved seed with clean seed is one means to increase yield, but information asymmetry between buyers and sellers on seed quality may restrict market supply of this input. In this article we develop a model of the seed market in which clean seed is treated as a capital good providing benefits over several seasons. To determine farm demand for clean seed, we conducted a survey of 182 potato farmers in the major potato growing areas of Indonesia to elicit their perceptions of seed quality from different sources, and derive farmers' “willingness‐to‐pay” for quality potato seed. Results indicate that the effects of information asymmetry on seed supply may be partially offset by the “reputation” of specialized seed producers. Nevertheless, marginal returns to disease‐free seed appear to significantly exceed marginal costs, indicating that improving supply of quality seed will contribute strongly to productivity growth in potato. We discuss several policy options to encourage supply and utilization of quality potato seed.     

我国玉米制种产业发展现状及战略选择

该文在分析我国玉米制种产业发展基本情况的基础上,提出了市场供需矛盾突出、基地合作关系不稳、效益下降导致企业兑付困难上访事件时有发生、市场秩序较为混乱等4方面主要问题。从持续发展动力不足、市场主体带动力不足、政府宏观调控力不足、缺乏养护导致地力不足等4方面分析了存在的主要原因。为推进我国玉米制种产业科学发展,从政策叠加、项目支撑、自然优势、市场转型4方面分析了玉米制种产业发展的重大机遇。从加快实施玉米制种基地规模化、机械化、标准化、集约化等"四化基地"建设、加快建立种业宏观调控体系、加快构建新型种业经营体系等三方面提出了对策建议。为有效落实对策建议,提出了永久制种田建设的概念、保护国家玉米制种战略资源的理念、开展轮茬作业实施目标价格补贴的措施以及健全我国种业宏观调控体系的途径等具体政策建议。     

Supplying trees in an era of environmental uncertainty: Identifying challenges faced by the forest nursery sector in Great Britain

In recent years, numerous articles have addressed management strategies aimed at assisting forests to adapt to climate change. However, these seldom take into account the practical and economic implications of implementing these strategies, notably, supply of forest plants and seed. Using semi-structured interviews with practitioners involved in the plant and seed supply chain in Great Britain, we highlight a series of practical and economic bottlenecks commonly encountered in the supply of locally sourced seed and domestically produced planting stock for native woodland and hedging markets. We find that adoption of alternative seed sourcing strategies, designed specifically to account for directional climate warming, is likely to exacerbate existing problems by adding further complexity to decisions nurseries make about tree species and seed origins to produce. The lack of long-term market predictability brought about by the current configuration of forestry grants and regulations and, in particular, the administrative systems for processing grant applications is identified as a major impediment to having a sustainable and competitive supply of home-grown and currently adapted planting stock. Finally, the time and effort it takes to supply healthy plants for native woodland creation projects deserves much wider recognition throughout the industry and will be crucial if planting objectives are to be met sustainably.     

The economic impacts of technology and climate change: New evidence from U.S. corn yields

Over the past century, U.S. farmers have been offered a steady stream of new agricultural technologies, and more recently, experienced climate change. Because these two events have been occurring simultaneously, identifying their separate effects is difficult, and misimputation is easy. This article explicitly examines the economics of technical change and the interaction between weather and technology as revealed in a half century of panel data on U.S. Midwest rainfed state‐average corn yields. Observed yields reflect two components: yield potential and damage to the potential caused by weather and pests. Yield potential is modeled as a stochastic production frontier where nitrogen fertilization, public corn research, and introduction and adoption of biotech corn seeds impact yield potential and excess heat impacts nitrogen productivity. The yield‐damage/damage‐control function permits biotech corn plants to abate adverse effects of weather and pest events. Results include the following: nitrogen use, public corn research, and biotech seed‐corn adoption increase yield potential; soil moisture stress reduces yield potential, and excess heat severely reduces nitrogen productivity. Biotech corn plants abate yield damage caused by soil moisture stress but not excess heat.     

Trade Reform and the Corn Market: Prospects for the World Trade Organization Negotiations on Agriculture

Government support and trade restrictions on agricultural commodities are among the most globally distorting protectionist policies. This is especially true with regards to corn. Vast production subsidies and import barriers, primarily within the European Union and China, have artificially inflated the global supply of this commodity, while restricting the available consumer markets. This impact is augmented by the preferential treatment granted in these countries to the production and importation of the best available substitute to corn, soybeans. Using an econometric model with commodity data over the past 20 years, this article predicts the likely impact of potential World Trade Organization (WTO) trade pacts on these corn trade distortions. Despite the WTO setback in Seattle, the vast global benefits resulting from agricultural trade liberalization in corn alone validate a continued push towards freer trade.     

Short supply chain participation and market performance for vegetable farmers in China

The fresh food supply chain in China has begun to reduce the number of intermediaries that connect producers and consumers. Using farm‐level data, this paper investigates the impacts of short supply chain participation on vegetable farmers’ market performance, including profits, productivity, production cost, price and price risk. The results show that the participation in a short supply chain is a profit‐maximising strategy and risk management tool for farmers. The increase in profit is attributed to productivity advantages, farm size expansion, and risk reduction rather than because of price premiums or cost savings. A policy implication is that short supply chain promotion has many benefits, but the government should be more concerned about the sustainability of short supply chains.     

Decompositions of corn price effects: implications for feed grain demand and livestock supply

This article examines how corn prices affect the demand for feed grains and the supply of livestock outputs. The differential approach to the theory of the multiproduct firm is employed to examine ex ante decisions about feed grain demand and livestock supply. The estimation results suggest that livestock producers have little flexibility in adjusting the demand for corn in response to an increase in corn prices. The substitutable relationship between corn and distillers’ grains contributes to alleviating pressures on feed costs in response to high corn prices. In addition, the estimation results highlight that the composition of livestock supply can be altered by changes in livestock prices. On the basis of the estimated elasticities, the decompositions of profit‐maximizing input demand are conducted to examine the effects of changes in corn prices on feed grain demand and livestock supply. The decomposition results reveal that an increase in corn prices reduces corn demand but raises the demand for distillers’ grains mainly due to the substitution effects of corn price changes. The decomposition results also show that an increase in the price of corn reduces cattle supply but raises the supply of chicken and pork due to the output relationships in supply.     

A model of the U.S. food system: What are the determinants of the state vulnerabilities to production shocks and supply chain disruptions?

We adapt a Ricardian general equilibrium model to the setting of U.S. domestic agri-food trade to assess states’ vulnerability to adverse production shocks and supply chain disruptions. To this end, we analyze how domestic crop supply chains depend on fundamental state-level comparative advantages—which reflect underlying differences in states’ cost-adjusted productivity levels—and thereby illustrate the capacity of states to adapt to and mitigate the impacts of such disruptions to the U.S. agricultural sector. Based on the theoretical framework and our estimates of the model's structural parameters obtained using data on U.S. production, consumption, and domestic trade in crops, we undertake simulations to characterize the welfare implications of counterfactual scenarios depicting disruptions to (1) states’ agricultural productive capacity, and (2) interstate supply linkages. Our results emphasize that the distributional impacts of domestic supply chain disruptions hinge on individual states’ agricultural productive capacities, and that the ability of states to mitigate the impacts of adverse production shocks through trade relies on the degree to which states are able to substitute local production shortfalls by sourcing crops from other states.     

玉米论略

玉米是我国种植面积最大的粮食作物,是今后一个时期消费需求增长最快的粮食品种,同时也是未来满足我国粮食需求增长的主要粮食品种。玉米生产中存在的突出问题是生产稳定性差,受干旱影响较大,实用技术普及率和机械化水平低,种业发展水平低,但玉米生产发展的单产潜力大,扩大种植面积也有潜力。促进我国玉米产业发展要坚持立足国内实现基本自给,转变生产方式,优化区域布局,加大扶持力度,搞好加工业和进出口调控;大力推进良种研发应用,着力解决干旱问题,积极推进机械化,抓好主产区,减小产后损失,完善收储政策。     

收储制度改革背景下农户玉米种植调整行为研究基于优势产区与非优势产区423个农户调查数据对比

目的 为了解收储制度改革背景下农户玉米种植调整行为,从而对优化农业种植结构、保障玉米稳定供给的科学决策提供参考。方法 文章基于辽宁、吉林、黑龙江、内蒙古423个农户调查数据,通过建立有序多分类Logistic回归模型,将玉米种植优势产区与非优势产区样本农户的玉米种植调整行为进行对比分析。结果 研究发现不同产区农户玉米种植调整行为影响因素存在差异。在优势产区,农户新品种采用意愿、家庭劳动力数量、其他作物面积、玉米收入占比、生产者补贴标准满意度对玉米种植调整行为影响显著。在非优势产区,农户上一年种植面积、玉米收入占比、合作组织对玉米种植调整行为影响显著。结论 进一步完善生产者补贴机制,适当提高优势产区玉米补贴标准;加强玉米良种研发,实施“藏粮于技”战略;加强对农业经营主体的培育扶持,有效推动种植结构调整。     

Warming temperatures will likely induce higher premium rates and government outlays for the U.S. crop insurance program

Likely climate change impacts include damages to agricultural production resulting from increased exposure to extreme heat. Considerable uncertainty remains regarding impacts on crop insurance programs. We utilize a panel of U.S. corn yield data to predict the effect of warming temperatures on the mean and variance of yields, as well as crop insurance premium rates and producer subsidies. While we focus on corn, we demonstrate that the subsidy impacts are likely to carry over to other major program crops. We find that warming decreases mean yields and increases yield risk on average, which results in higher premium rates. Under a 1°C warming scenario, we find that premium rates at the 90% coverage level will increase by 39% on average; however, there is considerable statistical uncertainty around this average as the 95% confidence interval spans from 22% to 61%. We also find evidence of extensive cross‐sectional differences as the county‐level rate impacts range from a 10% reduction to a 63% increase. Results indicate that exposure to extreme heat and changes in the coefficient of variation are large drivers of the impacts. Under the 1°C warming scenario, we find that annual subsidy payments for the crop insurance program could increase by as much as $1.5 billion, representing a 22% increase relative to current levels. This estimate increases to 3.7 billion (57%) under a 2°C warming scenario. Our results correspond to a very specific counterfactual: the marginal effect of warming temperatures under current technology, production, and crop insurance enrollments. These impacts are shown to be smaller than the forecasted impacts under a commonly used end‐of‐century general circulation model for even the most optimistic CO₂ emissions projection.     

Traceability, Liability, and Incentives for Food Safety and Quality

Recent food scares such as the discoveries of Bovine Spongiform Encephalopathy and E. coli -contaminated spinach have heightened interest in food traceability. Here, we show how exogenous increases in food traceability create incentives for farms and marketing firms to supply safer food by increasing liability costs. We model a stylized marketing chain composed of farms, marketers, and consumers. Unsafe food for consumers can be caused by either marketers or farms. We show that food safety declines with the number of farms and marketers and imperfect traceability from consumers to marketers dampens liability incentives to supply safer food by farms.     

基于Nerlove模型的玉米供给反应研究*——以吉林省为例

［目的］吉林省是以玉米为主要粮食作物的产量大省,吉林省玉米生产在保障国家粮食安全方面发挥着重要的作用。2016年国家取消玉米临时收储政策,实行“价补分离”政策（既市场化收购+补贴）。在玉米价格逐步市场化的形势下,为探究吉林省玉米种植面积对价格变动的反应程度,［方法］文章利用1985—2015年吉林省玉米种植面积、玉米平均出售价格、玉米的物质成本投入、玉米与大豆的每667m2收益比值、玉米与水稻的每667m2收益比值的时间序列数据,通过运用Nerlove模型,测算吉林省玉米播种面积对价格、物质成本、与大豆和水稻的每667m2收益比值的供给反应。［结果］吉林省玉米的短期供给弹性为049,长期供给弹性为063,短期供给弹性和长期供给弹性均小于1,缺乏弹性,吉林省玉米种植面积对价格变动的反应较为迟钝。［结论］提出完善农业耕作制度,推进玉米目标价格制度改革,优化玉米收购市场结构政策建议。     

内蒙古奶源供给组织模式比较分析与目标模式研究

[目的]随着生产力的发展,各种新型奶源供给组织模式应运而生,这是生产发展的必然。[方法]文章在比较研究、案例研究和实证分析基础上,对当前内蒙古奶源供给组织模式的基本经营方式进行定性比较和定量的测量,分析了当前内蒙古乳品产业链奶源供给组织模式的6种基本经营方式。[结果]研究指出:当前内蒙古奶源供给的各种模式,这些组织模式均是经营者在生产经营中处于利益诉求理性选择的结果,其各具优劣势,但从无论从组织生产、利益分配、产业化程度、销售各个方面都能充分证明,合作社将成为内蒙古奶源供给组织的主要形式和目标模式。[结论]内蒙古"奶牛专业合作社"的奶源供给组织模式的完善和普遍推进还需长期努力。     

Can life cycle assessment be used to evaluate plant breeding objectives to improve supply chain sustainability? A worked example using porridge oats from the UK

The challenge for agricultural production in the 21st century is to produce sufficient high-quality food whilst minimizing impact. Life cycle assessment (LCA) can help by identifying the parts of a supply chain with the greatest environmental impact, and to determine which technologies – for example plant breeding – may be most appropriately employed to minimize negative impacts. A ‘plough-to-plate’ LCA of a porridge oat production chain was undertaken using data that corresponds to the inputs and outputs of an indicative supply chain. The greatest environmental impact of the porridge oats life cycle occurs in crop production and cooking. There are traits for oats that are available for manipulation by plant breeders, which can influence these areas; these include yield, nitrogen use efficiency and beta-glucan content. Therefore plant breeding may be a useful strategy for improving the sustainability of the crop. However LCA cannot be a definitive tool to guide plant breeding and therefore this approach needs to compliment others. Nevertheless this study highlights that porridge oat supply chain sustainability would benefit from an integrated effort stretching from the geneticist to consumer; a finding that is likely to be relevant to other food supply chains.     

Promoting smallholder seed enterprises: quality seed production of rice,maize, sorghum and millet in northern Cameroon

Food and Agriculture Organization of the United Nations (FAO) conducted two projects in Cameroon on strengthening rice, and sorghum, maize and millet seed production by smallholder seed enterprises (SSEs). Farmer groups (respectively, 25 SSEs and 114 SSEs) were formed or strengthened and trained. Sixty-six selected lead farmers were trained on the administering and managing of revolving funds. The groups were then linked to the Extension Service (for continuous technical advice), Agriculture Research for Development Institution (continuous supply of needed seed), National Seed Service (seed certification) and to financial institutions (financial support). The results obtained showed that 60 and 59.6 per cent, respectively, of the groups sustained their activities two to three years after the projects ended. Total certified rice seed produced increased to 800 tonnes (t) against 267t at the beginning. For the other cereal project, the total certified seed produced was 719.2t against 497t at its beginning. The use of quality seed rice together with good agronomic practices increased yields (up to 8.0t/ha against a scant 2t/ha before). All interviewed farmers stressed that the seed business was profitable and helped achieve higher living standards and diversify their activities. Seasonal incomes were more than US$1,783.31. Finally, both FAO projects helped generate farmers' income to about US$2,114.871, produced 447,954t of cereal grain and thus improved food security and alleviated poverty. The Cameroonian success could be repeated elsewhere.     

Determinants and impact of sustainable land management (SLM) investments: A systems evaluation in the Blue Nile Basin,Ethiopia

Ongoing debate over water management along the Blue Nile and land degradation in Ethiopia emphasizes the need for efficiency gains in agricultural production through sustainable land management (SLM). However, previous SLM studies overlook the tradeoffs involved in maintaining SLM investments over time. We address this limitation by combining a household survey that evaluates the economic impacts of SLM investments and maintenance, with a hydrological model that explores location‐specific infrastructure effects. We then use a multi‐market model to evaluate the impacts of alternative SLM investments on agricultural production, prices, and incomes over time. Analysis suggests SLM investments must be maintained for at least seven years to show significant increases in value of production, and that terraces on moderate and steep slopes are most effective in increasing agricultural yields. However, the benefits of terracing do not outweigh the cost of foregone off‐farm labor opportunities, nor compensate for lower agricultural prices from increased supply. Thus, SLM investments must be paired with other input and infrastructure investments, as well as subsidies for initial labor costs, in order to incentivize adoption and long‐term SLM maintenance.     

Recent weather fluctuations and agricultural yields: implications for climate change

We summarize recent statistical analyses that link agricultural yields to weather fluctuations. Similar to other sectors, high temperatures play a crucial role in predicting outcomes. Climate change is predicted to significantly increase high temperatures and thereby reduce yields. How good are such models at predicting future outcomes? We show that a statistical model estimated using historic US data on corn and soybean yields from 1950 to 2011 is very capable of predicting aggregate US yields for the years 2012–2015, where 2012 was much hotter than normal and is expected to become the new normal under climate change. We conclude by discussing recent studies on the implication of predicted yield declines with a special focus on adaptation and commodity prices.     

The new economic geography of land use change: Supply chain configurations and land use in the Brazilian Amazon

In this paper we present a framework for understanding regional land use processes by incorporating the concept of agglomeration economies into agricultural frontier theory. We show that agricultural firms can obtain positive externalities from locating in close proximity to other agricultural firms, leading to agglomeration economies. Agglomeration economies lead to high levels of competition and diversity within a local agricultural supply chain and influence local prices, information flows, and private enforcement of environmental institutions. We use the theory of agglomeration economies to understand the development of soybean production in two counties along the Santarém-Cuiaba (BR-163) highway in the Brazilian Amazon: Santarém, Pará and Sorriso, Mato Grosso. We conclude that differences in environmental and land tenure institutions influenced the occurrence of agglomeration economies in these two counties, which in turn affected the total factor productivity of soy in each region. In particular, the supply chain became extremely competitive and diverse in Sorriso where few environmental regulations existed, while environmental restrictions reduced the diversification of the supply chain in Santarém. The presence of a soy agglomeration economy in Sorriso spurred innovation, increased productivity, and led to extremely rapid soy expansion in that county, while the monopolistic supply chain in Santarém reduced producers’ access to land and capital and impeded soy expansion.