The Impacts and Causes of Land Fragmentation on Farm Productivity: Case Review of East African Countries

This report provides an overall assessment of land fragmentation problems in East Africa. Many parts of East Africa have become highly fragmented, putting development systems and activities in these areas at risk of complete collapse. Land fragmentation occurs when land gets converted for agriculture, industrialization, or urbanization, invaded by non-local plants, or enclosed for individual use and by subdividing farmlands into subsequent smaller units called parcels with varying average farm sizes. Fragmentation results from inappropriate agricultural development processes and ineffective land use planning that fails to recognize how farmland is used, and the importance of its interconnected areas. Insecurity of tenure and resource rights are key factors in making this possible. Land fragmentation is one of the key reasons why the ability of most resources in East Africa becomes scarcer, and those remaining become “privatized” by more powerful community members—keen to maintain their access to them. Such individualistic attitudes are new and disadvantage the poorest even further by affecting the traditional customary safety nets and agricultural outputs. Neither the government nor customary governance systems effectively protect resource access for the poorest. This review summary report identifies the key causes, measures, and implications, government interventions, and the common remedies to land fragmentation problems in the East African Countries of Kenya, Uganda, Rwanda, and Tanzania including neighboring Ethiopia, and the Sudan. The findings indicated from 2005 to 2015, the population kept increasing for all the named countries in East Africa with Rwanda and Uganda having a substantial increase in population density. The study review further explores the trend in the performance of agriculture by average farm sizes within the intervals of five years by highlighting their strong linkages and found that the average farm size has declined drastically, especially for Kenya. This can only mean that small farms kept becoming smaller and smaller and that there were more small-scale farmers. The results further depicted that the major and commonly cultivated food crops among the East African countries include maize, sorghum, rice, cassava, sweet potatoes, bananas, Irish potatoes, beans, peas, etc., with maize yields (Mt/ha) in 2003 for Uganda being the highest (1.79 Mt/ha) and the lowest in Rwanda (0.77 Mt/ha) respectively. Therefore, from the review results, recommendations are being made as to how the negative impacts of land fragmentation on agricultural productivity can be reduced or mitigated. One way is by community sensitization and awareness about the importance of land consolidation and its proposition on farm productivity.

Evaluating the Impacts of Human Activities on Diversity, Abundance, and Distribution of Large Mammals in Nimule National Park, South Sudan

Globally, human activities have a significant impact on the diversity, abundance, and distribution of large mammals in Protected Areas (PAs). These disturbances increase human pressure on biodiversity and species habitats, highlighting the need for conservation. This study aimed to assess the abundance and distribution of large mammals in different habitat types within Nimule National Park (NNP) and understand the impacts of human activities on them. Data on the abundance and distribution of large mammals and their respective habitat types were collected through line transect surveys. Human activity signs were observed and recorded along the transect lines. To estimate the impacts of human activities on the diversity, abundance, and distribution of large mammal species, as well as to identify any significant differences between them and their habitat types, the study utilized the Kruskal Wallis test, Polynomial multiple regressions, and diversity indices. The findings from the Shannon-Weiner and Simpson indices indicated that large mammal species were more diverse inside the park (H’ = 1.136;D = 0.570) compared to the buffer zone (H’ = 0.413;D = 0.171), with 85% (443 out of 510 samples) recorded within Nimule National Park. The species abundance showed a semi-balanced status (0.58). The diversity results among different habitat types revealed that large mammals were more diverse and highly distributed in both open woodlands (244) and dense woodlands (192), while riverine vegetation had the lowest diversity (8). Statistical tests demonstrated a highly significant difference at a 99% confidence interval (p-value = 0.01) between habitat types and identified species of large mammals. Additionally, the results highlighted the high abundance of Uganda kob (274), baboons (141), and warthog (57) across most habitat types, accounting for at least 75% of their distribution. The most prevalent human activities observed were cattle footprints (27%) and cattle dung (14%). Human footprints and tree cutting combined accounted for 9%, indicating the practice of livestock grazing, poaching, encroachment, and fuelwood collection by local communities. However, these activities did not appear to significantly impact the diversity, abundance, and distribution of large mammals in Nimule National Park. Therefore, it is crucial to foster shared responsibilities and engage relevant stakeholders in the management and conservation of large wildlife species. Regular community awareness programs should be implemented to cultivate a sense of ownership. Moreover, it is recommended that a comprehensive survey be conducted on the population status of all mammal species in Nimule National Park, including its surrounding Buffer Zone. Monitoring the impact of human activities on their behavior and habitats using satellite images should also be carried out at least every five to ten years.

(Re)assessing Climate-Smart Agriculture practices for sustainable food systems outcomes in sub-Saharan Africa:The case of Bono East Region,Ghana

This research paper assesses the reality of Climate-Smart Agriculture(CSA)practices’potential to promote the outcomes of sustainable food systems(SFS)within Ghana’s smallholding agriculture context.The study demon-strates that rural farmers generally perceive CSA’s contribution to‘food and nutrition security’and‘economic performance’as more important than CSA’s contribution to‘social equity’and‘environmental stewardship’.From a narrow perspective,the study demonstrates that farmers perceive CSA’s potential to‘prevent pest and disease outbreaks’and‘increase human capital information’as the most important contribution of CSA to SFS outcomes.In contrast,CSA’s potential to promote environmental stewardship is perceived as the least important among Ghana’s rural farmers.This enormity of displacement of smallholders’perceptions at large is motivated by de-mographic,socioeconomic and ecological factors.Moreso,the CSA for SFS outcomes narratives is driven by farmers’self-apprise,social networks and other local information dissemination agents.Furthermore,research findings suggest farmers’awareness of CSA practices and interventions is deficient owing to unmet training and information needs for approximately 82%of the CSA practices and interventions.This situation elucidates the dichotomy of CSA practices’narratives as tools for attaining food,nutrition security and economic performance to the detriment of critical issues such as increasing awareness and building farmers’capacity to engage with CSA practices while also managing socio-ecological trade-offs that emerge over time due to engagement with CSA.Critical(re)orientation is needed across the scale to drive CSA practices and interventions that confine cli-mate adaptation and food production practices within safe planetary boundaries without undermining social,economic,food and nutrition security needs.

Assessing Forest Cover Distribution, Species Diversity, and Richness of the Buffer Zone for Strategic Forest Management Planning for Nimule National Park, South Sudan

Natural forest ecosystems play an essential role in the conservation of biodiversity of many plants and animals by providing them with habitat and suitable environments. Studies have shown that biodiversity-protected areas reduce the loss and degradation of natural habitats to various wild species of plants. This study examined the forest resources in five subzones by conducting tree/shrub species inventory to be able to develop an effective forest management plan for the Buffer Zone Forest Reserve for the sustainable conservation of flora and fauna of Nimule National Park. This is with the view to identify the main tree and shrub species;assess the composition, distribution, and abundance of various tree/shrub species;to determine the species diversity as well as the richness of these areas in terms of growth and performance where DBH and heights of trees/shrubs in the circular sample plots were measured. The results revealed the overall mean DBH and H of 13.83 cm and 6.61 m respectively. The highest number of trees was obtained in subzone B followed by D, while the least were found in subzone A. The overall mean tree/shrub density was 0.83 tons/ha. The mean total basal area and volume per hectare were 3252.74 m2/ha and 46,540.82 m3/ha respectively. The overall species abundance and distribution indicate Combretum spp, Cedrella spp., Grewia mollis, Acacia Sieberiana, Ziziphus abysinica, and Acacia seyal were the most dominant species, with over 12 species richness at the deposition side of the River Nile, 13 species at the western side of the Nile, the Administration site shows only 7 species, the lowland of Mt. Gordon show over 14 different species, whereas over 10 species were found on the top of Mt. Gordon. The overall mean diversity indices and evenness of H’, D, and E depicted 2.507, 0.871, and 0.840 respectively. These results yielded are relatively moderate. Therefore, conservation efforts are very necessary to improve and maintain the quality of vegetation cover.

Determining the Effects of Selected Organic Fertilizer on Growth and Yields of Tomato (Lycopersicon esculentum: Var. Rio Grande Tomatoes) in Mundri West County, Western Equatoria State, South Sudan

Worldwide, the demand for agro-organic foods that are healthy, nutritious, and environmentally friendly is increasing dramatically across all nations among consumers. Tomatoes being one of the dietary requirements in almost every meal is not exceptional and its availability in the market all year round is very important to farmers as well as consumers because it is highly demanded as a vegetable par excellence;which is either eaten raw in salads, cooked or processed into liquid ingredients. This study investigates the impact of chicken, goat, and cow manure treatments on tomato plant growth response to height, leaf length, and width, as well as fruit yield. The experimental field trials were conducted over two planting seasons in Mundri West County. It followed a Complete Randomized Design (CRD) approach, consisting of four blocks. Each block contained three treatments replicated four times and a control group. The data of measured parameters from all 16 plots were subjected to one-way Analysis of Variance (ANOVA) using the Gen Stat 14th Edition software. The findings indicate significant differences (P < 0.05) among all the different organic manure applications on tomato plant growth parameters compared to the control group. Chicken manure resulted in the tallest tomato plants (30.1 and 37.9 cm), longest leaves (9.9 and 10.4 cm), and widest leaves (2.1 and 2.5 cm) in both seasons respectively. The study showed plots treated with chicken manure had a highly significant impact (P < 0.05) on the prevalence of aphids (1.0) and white flies (1.4) with the lowest value compared to those with cow and goat manure applied. Additionally, chicken manure led to the highest yields (39.30 and 49.49 tons/ha) in both seasons. Based on these findings, it can be concluded that using chicken manure effectively improves the performance of Rio Grande Tomatoes, and thus, farmers are encouraged to utilize chicken manure to maximize their tomato yields.

Factors influencing hybrid maize farmers' risk attitudes and their perceptions in Punjab Province,Pakistan

Hybrid maize farmers have to face diverse kinds of climate, biological, price and financial risks. Farmers＇ risk perceptions and risk attitudes are essential elements influencing farm operations and management decisions. However, this important issue has been overlooked in the contemporary studies and therefore there is a dearth of literature on this important issue. The present research is therefore, an attempt to fill this gap. This study aims to quantify hybrid maize farmers＇ perceptions of disastrous risks, their attitudes towards risk and to explore the impacts of various farm and farm household factors on farmers＇ risk attitudes and risk perceptions. The present study is conducted in four hybrid maize growing districts of Punjab Province, Pakistan, using cross-sectional data of 400 hybrid maize farmers. Risk matrix and equally likely certainty equivalent （ELCE） method are used to rank farmers＇ perceptions of four catastrophic risk sources including climate, biological, price and financial risks and to investigate farmers＇ risk aversion attitudes, respectively. Furthermore, probit regression is used to analyze the determinants affecting farmers＇ risk attitudes and risk perceptions. The results of the study showed that majority of farmers are risk averse in nature and perceive price, biological and climate to be potential sources of risks to their farm enterprise. In addition, analysis divulges that distance from farm to main market, off-farm income, location dummies for Sahiwal and Okara, age, maize farming experience, access to extension agent, significantly （either negatively or positively） influence farmers＇ risk attitudes and risk perceptions. The study delivers valuable insights for farmers, agricultural insurance sector, extension services researchers and agricultural policy makers about the local understanding of risks to hybrid maize crop in developing countries, like Pakistan, and have implications for research on farmers＇ adaptation to exposed risks.

Direct farm, production base, traceability and food safety in China

With the rapid growth of China＇s economy, rising demand for safety food has been accompanied by frequent food safety scandals. Given that China＇s farming is dominated by millions of small-scale farms, ensuring food safety is a major challenge facing the public and private sectors. The direct farm （DF） program, initiated in 2008, represents one of the government＇s major initiatives to modernize the distribution of fresh fruit and vegetables （FFV） and improve food safety. Under the DF program, participating national and international retailers are expected to establish more direct procurement relationships with farm communities. While it is often claimed that greater participation by retailers in the production and post-harvest processing implied the DF program will lead to improved quality, safety and traceability, systematic evidence remains elu- sive as existing studies are largely narrative, based on case studies, or theoretical inference. Little empirical evidence is available for a broader evaluation of the DF program. This paper aims to fill this gap by assessing the overall performance of a single retailer＇s DF experience with respect to the procurement and food safety of FFV. We use data from a survey of production managers of 35 DF production bases （PBs） spread across 11 provinces, 3 cities and 1 autonomous region in China. The results show a mixture of opportunities and challenges. On one hand, the DF program improves production practices and distribution channels of FFV produced on its PBs, thus facilitating the move of China＇s food system towards improved food safety compliance. On the other hand, significant heterogeneity in the traceability of food and the ability of DF to meet higher safety standards is evident both across major product categories and across household-operated vs. firm-operated PBs. The paper concludes with policy implications.

Maize production under risk:The simultaneous adoption of off-farm income diversification and agricultural credit to manage risk

Farmers in Pakistan continue to produce maize under various types of risks and adopt several strategies to manage those risks. This study is the first attempt to investigate the factors affecting the concurrent adoption of off-farm income diversification and agricultural credit which the farmers use to manage the risk to maize production. We apply bivariate and multinomial probit approaches to the primary data collected from four districts of Punjab Province in Pakistan. The results show that strong correlations exist between the off-farm diversification and agricultural credit which indicates that the use of one risk management strategy leads to another. The findings demonstrate that education, livestock number, maize farming experience, perceptions of biological risks and risk-averse nature of the growers significantly encourage the adoption of diversification as a risk management tool while farm size inversely affects the adoption of diversification. Similarly, in the adoption equation of credit, maize farming experience, farm size, perceptions of price and biological risks and risk attitude of farmers significantly enhance the chances of adopting agricultural credit to manage farm risks. These findings are important for the relevant stakeholders who seek to offer carefully designed risk minimizing options to the maize farmers.

Feasibility of using polypropylene ground cover upon consideration of long-term responses of sweet cherry nutrition and profitability

The impacts of synthetic polypropylene ground cover in the row area of sweet cherry (Prunus avium L.) trees (‘Regina’/’Gisela 6’) on soil nutrient availability, tree mineral nutrition and productivity, and economic returns were investigated on a Van Horn fine sandy loam soil at Hood River OR, from 2000 to 2007. Treatments included 2.44-m wide synthetic fabric ground cover made of black, woven poly-propylene over the row area of cherry trees (woven fabric), and no ground cover but with herbicide applications in the row area with the same width as the polypropylene ground cover (herbicide strip) – standard industry practice. This article reports the plant nutrition and soil fertility results of 2006 and 2007 and profitability and feasibility results of 2000 to 2007. Tree leaf nitrogen (N) concentrations were significantly higher with 9 to 14% increases using woven fabric compared with herbicide strip in 2006 and 2007. However, leaf sulfur (S) concentrations were significantly lowered with woven fabric in the two seasons. Woven fabric resulted in fruit with comparable quality and possible greater storability under enhanced fruit yields than herbicide strip in both years. Woven fabric was more profitable than herbicide strip based on an additional net present value of $2,606 ha-1 by the end of this study. Woven fabric had annual gross returns greater than annual costs in the fourth year after planting by $8,181 ha-1 relative to herbicide strip, and had cumulative net returns greater than total costs of all previous years in the sixth year after planting by $17,796 ha-1 over herbicide strip. However, to establish a sweet cherry orchard with woven fabric, the grower would spend an additional $4,332 ha-1 over herbicide strip. In conclusion, woven fabric is a profitable and sustainable in-row ground management alternative to herbicide strip for orchards from a long-term perspective.

Explaining farmers'reluctance to adopt green manure cover crops planting for sustainable agriculture in Northwest China

Green manure cover crops(GMCCs)planting has a potential for mitigating greenhouse gas emissions(GHG)in agroecosystems and provides important ecosystem services,thereby achieving the Sustainable Development Goals(SDGs)stipulated by the United Nations.However,the advantages of cultivating GMCCs on arable land are not widely recognized.For example,in the whole of China,the GMCCs planting area is less than 3.5%of total arable land.The aim of this study is to explore reasons for the low adoption rate of GMCCs planting.Using best–worst scaling(BWS)approach,farmers ranked their preferred conservation practices including three types of GMCC cropping systems.Taking Gansu Province in Northwest China as a case study,a survey with 276 farmers was conducted.The findings indicated that three factors are related to the low adoption rate of GMCCs:1)farmers preferred improving farmland irrigation facilities and substituting chemical fertilizers with organic rather than planting GMCCs;2)lack of awareness and understanding of government policy on GMCCs and limited access to training courses;3)financial support and subsidies from the government are insufficient.This study provides insights and strategic implications for policymakers on how to further promote GMCCs in the future.

Evaluation of Greenhouse Gas Emissions from and the Economic Efficiency of the ＂Hita City Biomass Recycle Center＂

Many biomass recycling facilities have been established in Japan, but its environmental efficiencies have been studied little. MIC has stated that these facilities do not work as well as expected. The environmental and economic efficiencies ofa biomass recycling center （representative of other recycling facilities） in Hita city are assessed here. The center was built to decrease the amount of waste needing to be disposed of, and is unusual in that it generates electricity using the methane produced. Electricity produced from biomass sells at a higher price than electricity sold by electricity companies in Japan, and this strongly affects the recycling center operation. The environmental efficiency of the recycling center was assessed using a lifecycle assessment method, and the economic efficiency was assessed from the amounts of greenhouse gases emitted and the running costs. As the result, it was clear that the recycling center emits about 20% of the greenhouse gases that were previously emitted. Treating biomass at the recycling center costs 1,356 yen per ton of biomass throughout the year. In conclusion, the recycling center decreases the environmental footprint of Hita city. The cost of decreasing greenhouse gas emissions is about 1,400 yen per ton of biomass.

Estimating Urban Households’ Willingness-to-Pay for Upland Forest Restoration in Vietnam

Increased urbanization coupled with increased reliance of urban communities on rural areas for ecosystem service provision is a challenge faced by many nations. The ability of urban households to directly support restoration efforts in surrounding rural regions represents an underappreciated funding stream for ecological restoration. This study explored the willingness of urban households to support forest restoration in Vietnam. We surveyed 211 households (HHs) in the capital city Hanoi, Vietnam. A Maximum Likelihood Estimator (MLE) model allowed us to obtain the parameters of our model and quantify mean Willingness-to-Pay (WTP) for a program of forest restoration in addition to identifying factors influencing the decision of WTP. Generally, over forty percent of the households surveyed are willing to pay for forest restoration and the mean value of WTP is 37,830 VND ($1.73) per household per month. WTP depends on endogenous and exogenous factors including level of education, income, female-to-male ratio in the household, attitude toward payment for monthly electricity consumption, and awareness of payment for environmental service. Our results suggest that urban household’s demand for forest restoration is real, and represents an untapped source of restoration funding. Policy-makers should take actions to apply charges on water bills to turn this potential into reality for restoration projects in Vietnam if the benefits from restoration outweigh the costs based on our findings.

Economic Valuation of River Conservation towards International Tourists’ Preferences and Willingness to Pay for Ecofriendly Services of Hotel Industry: A Case Study of Namxong River in Vangvieng District, Laos

Using choice experiment, the objective of this study is to estimate international tourists’ preferences and willingness to pay for ecofriendly services which related to river and natural environment conservation of hotel industry in Vangvieng, a popular tourist town in Lao PDR. We used the mixed logit to take into account of preference heterogeneity by allowing coefficients to be normally distributed and assumed to vary among individuals. The result shows that all ecofriendly practices offered in this study are significantly preferred by tourists. Income, age, and education did not have significant effect on the probability of choosing ecologically friendly practices of hotel and attributes to support the ecotourism of the area;however, this study provides important information that female tourists are more receptive to a new alternative. These findings do not only support the provision of good and green services in Vangvieng Town, but will also be useful for policy maker to enhance the sustainability of ecotourism in Laos.

Testing the Adding up Condition in Demand Systems

A test of the adding up condition in demand systems is crucial for determining whether a share format is admissible when the number of sample goods is smaller than the number of commodity choices available to consumers. This test requires the estimation of a demand system in a quantity format. It cannot be performed when a demand system is specified in share format. The share specification of any demand system is like a straight jacket: once worn, it forces the error covariance matrix to be singular and the adding up condition to hold whether or not the data generating process warrants it. The empirical verification of the adding up hypothesis uses a five-commodity sample selected from the Canadian Family Expenditure Survey with 4847 observations. Three specifications are considered: AIDS (Almost Ideal Demand System), QUAIDS (Quadratic AIDS) and EASI (Exact Affine Stone Index). The hypothesis is rejected in all three cases with a high level of confidence.

Estimation of CARA Preferences and Positive Mathematical Programming

The purpose of this paper is to combine the estimation of output price risk and positive mathematical programming (PMP). It reconciles the risk programming presented by Freund with a consistent estimate of the constant absolute risk aversion (CARA) coefficient. It extends the PMP approach to calibration of realized production outputs and observed input prices. The results of this specification include 1) uniqueness of the calibrating solution, 2) elimination of the tautological calibration constraints typical of the original PMP procedure, 3) equivalence between a phase I calibrating solution and a solution obtained by combining phase I and phase II of the traditional PMP procedure. In this extended PMP framework, the cost function specification involves output quantities and input prices—contrary to the myopic cost function of the traditional PMP approach. This extension allows for a phase III calibrating model that replaces the usual linear technology with relations corresponding to Shephard lemma (in the primal constraints) and the marginal cost function (in the dual constraints). An empirical example with a sample of farms producing four crops illustrates the novel procedure.

Variable Rate Technology and Cotton Yield Response in Texas

Variable Rate Technology （VRT） takes within-field variability into consideration and aims to match resource application to crop requirement. Even though Texas is the most important cotton producing state in the US, the rate of VRT adoption is very low here. Hence, analyzing the factors influencing the adoption and providing a regional estimate of the impact of VRT adoption on cotton yield is very important. This study used the 2009 Southern Cotton Precision Farming Survey to analyze the farm and farmer characteristics affecting the adoption of VRT among Texas cotton farmers and to empirically estimate the impact of adoption of VRT on cotton yield in Texas. A two-stage least square procedure with a logistic regression model in the first stage and a multiple linear regression model in the second stage was used to analyze the data. The study revealed that there are significant regional differences in adoption pattern within the state of Texas; and the farmers from the coastal region, where there is higher within-field variability, were more likely to adopt VRT compared to other regions. Younger farmers, farmers managing larger farms, and farmers who use computers for farming operations were more likely to adopt VRT. The results also showed that, on an average, the adoption of VRT does not lead to significant yield improvements for cotton in Texas. Since the impact of VRT adoption on yield is not significant, the source of economic advantage of VRT adoption in Texas may be the reduction of input cost.

California’s Agriculture-Related Local Air Pollution Policy

Air pollution is a critical environmental issue for California, which has some of the nation’s most polluted air basins and also the nation’s most stringent set of state and local air quality standards. This paper reviews my previous work in Lin (2011), in which I examine the effects of agriculture-related local regulations in California on air quality, as measured by the number of exceedances of the CO and NO2 standards, by exploiting the natural variation in policy among the different air districts in California. Agricultural burning policies and penalty fees reduce the pollution from CO. Other policies such as the prohibition on visible emission, fugitive dust, particulate matter, nitrogen and the reduction of animal matter are correlated with higher levels of CO. Regulations on orchard and citrus heaters have no significant effect on the number of exceedances of the CO and NO2 standards.

A More Renewable-Friendly Electrical Grid: Thermal Storage Refrigeration for Demand Response in California and Denmark

Energy storage technologies, which enable demand response, are being explored throughout the world as a component of strategies for switching to renewable intermittent energy sources and reducing peak loads. This study examines thermal storage refrigeration (TSR) technology as a case study for the potential value of demand response in California and Denmark. Using technical specifications from a TSR prototype developed at UC Davis and market data from California and Denmark, the analysis examines possible business models for the TSR refrigerators and highlights market characteristics that are important to its adoption. Results suggest that the TSR technology is not a viable option in the current market environment in Denmark, but could payback in less than 6 years in California if a part of a demand response based virtual power plant. In a hypothetical future scenario involving real-time pricing in the retail market, a high degree of price volatility would be needed to make TSR technology appealing to residential consumers. Based on this analysis, an interesting area of future work would focus on the market potential of TSR technology for commercial and industrial applications.

Grain Consumption and Production in Virginia: A Trend and Spatial Examination

This article couples an examination of grain production with Virginia’s livestock and poultry sector to analyze the overall magnitude and distribution of grain consumption in Virginia. Specifically, this paper describes the sources and trends over time of grain production and consumption;identifies grain surplus (and deficit) areas across Virginia’s counties;describes and applies a methodology to quantify livestock and poultry consumption requirements at the state- and county-levels;provides an updated assessment of Virginia’s ability to meet its feed grain needs;and discusses implications on the overall distribution system. Important results of the analysis reveal that grain consumption in Virginia is due mainly to demand in the poultry sector (primarily broilers and chickens). Furthermore, grain consumption in this state has generally declined over the last twenty years, due to decreasing livestock population numbers. Coupled with a slight upward trend in grain production, Virginia appears to be increasingly capable of meeting its grain needs. There is, however, an important east-west divide in the state, with western counties requiring more grain than they produce. Since grain does not appear to move from the relatively “production-rich” eastern counties, transportation infrastructure is important to bring in grain from outside the state.

电力工业厂网分开改革对火电企业效率影响的实证分析

2002年中国电力工业打破垂直一体化垄断经营模式,实施了"厂网分开"的电力工业改革。这次改革主要目的之一是通过引入竞争,提高电力企业效率。这一改革目的是否实现?本文对此进行了实证分析。运用DEA方法中的CCR模型和C2GS2模型,研究了改革前后火电厂综合效率、纯技术效率和规模效率的变化;并对参与2002年电力工业改革的电厂和未参与改革的独立发电厂进行了对比分析。研究认为,2002年的中国电力体制改革有效地促进了火电企业综合效率的提高。其中,纯技术效率得到了明显改善;但是与独立发电厂相比,改革后划归到五大电源集团公司的电厂规模效率却呈现相对下降趋势,本文对此进行了原因分析,并给出了相关政策建议。