基于GIS的典型白浆土区八五三农场耕地地力的定量评价

以黑龙江省典型白浆土区的853农场为例,采集农田耕层(0~20cm)样品1695个,以土地利用现状图的耕地图斑为评价单元,选取10个指标,利用特尔菲法和层次分析法,结合GIS技术,对853农场耕地地力进行了定量化的分析和评价。评价结果表明八五三农场耕地地力整体水平为:三级地占总耕地面积的35.47%,其次为二级和四级,分别占27.53%和20.86%,比例最小的是一级和五级地,分别占6.83%和9.30%。分级结果较好的体现了地区特点,同时明确了不同等级耕地的面积、空间分布格局,为探讨制定科学的培肥政策、提高作物产量和土壤基础地力,保护生态环境提供了定量化的分析依据。     

Agricultural input subsidies,extension services,and farm labour productivity nexus: Evidence from maize farmers in Tanzania

This paper examines the effect of agricultural input subsidies (AIS) and agricultural extension services (AES) on farm labour productivity in plots planted with maize in Tanzania, using panel data from the National Panel Survey in Tanzania. To control for the endogeneity of the two programmes, a control function and instrumental variable approach is used to estimate the effects of AIS and AES on farm labour productivity. The results show that AIS and AES are significant in raising labour productivity in maize-planted plots. Similarly, AIS and AES are also effective in increasing land productivity in these plots. Moreover, each programme has comparable effects on land productivity and farm labour productivity. These findings imply that public investments in AIS and AES are effective in raising farm productivity.     

Research and productivity in Thai agriculture

This paper examines the impact that publicly funded agricultural research has on productivity in crop production within Thailand. It tests empirically the two hypotheses that, first, publicly funded research and development (R&D) in crop production is a significant determinant of total factor productivity (TFP) in the crop sector and, second, that its social rate of return is high. The statistical analysis applies error correction methods to national level time series data for Thailand, covering the period 1970–2006. Emphasis is given to public research in crop production, where most publicly funded agricultural R&D has occurred. The role of international research spillovers and other possible determinants of TFP are also taken into account. The results demonstrate that public investment in research has a positive and significant impact on TFP. International research spillovers have also contributed to TFP. The results support the finding of earlier studies that returns on public research investment have been high. This result holds even after controlling for possible sources of upward biases present in most such studies, due to the omission of alternative determinants of measured TFP. The findings raise a concern over declining public expenditure on crop research, in Thailand and many other developing countries.     

Wheat breeding,productivity and slow variety change: evidence from the Punjab of India after the Green Revolution*

Variety change and genetic diversity are important means of combating crop losses from pests and diseases in modern agricultural systems. Since the Green Revolution, genetic diversity among wheat varieties released in India has increased but variety change on farms continues to be slow. In this article, we define and summarise indices of variety change and genetic diversity for the wheat varieties released and grown in Indian Punjab during the post‐Green Revolution period. We evaluate the effect of each index on technical efficiency with a Cobb‐Douglas yield model after testing for exogeneity. Findings support the hypothesis that slow variety change has offset the positive productivity effects of diversifying the genetic base in wheat breeding during the post‐Green Revolution period. Policies that speed the rate of variety change and contribute to a more equitable spatial distribution of modern varieties could support wheat productivity in the Punjab of India, reinforcing plant breeding successes.     

Production risk and technical inefficiency in Russian agriculture

This study investigates production risk and technical inefficiencyas two possible sources of the production variability that characterisedRussian agriculture during the last decade. The empirical analysisis conducted using panel data from 1996 to 2001 on 443 largeagricultural enterprises from three regions in central, southernand Volga Russia. A production function specification accountingfor the effect of inputs on both risk and technical inefficiencyis found to describe production technologies of Russian farmsmore appropriately than the traditional stochastic frontierformulation.     

Off‐farm work,land tenancy contracts and investment in soil conservation measures in rural Pakistan

This study examines the impacts of participation in off‐farm work and land tenancy contracts on the intensity of investment in soil‐improving measures and farm productivity. A multivariate Tobit model that accounts for potential endogeneity between the intensity of investment and the off‐farm work and tenancy contract variables is estimated for 341 rural households in Punjab province of Pakistan. An instrumental variable approach is also used to analyse the impact of tenancy contract and off‐farm work on farm productivity. The empirical results show that participation in off‐farm work and tenure security tends to increase the intensity of investment in long‐term soil‐improving measures. We also find that increases in off‐farm work and tenure security exert significant and positive effects on farm productivity.     

The contribution of UK farm assurance schemes towards desirable environmental policy outcomes

This study sought to evaluate the content of a range of UK primary production assurance schemes and their potential to support selected desirable agri-environmental policy outcomes. The schemes reviewed included those that fall under the Assured Food Standards umbrella plus eligible UK equivalents and examples of retailer and supplementary schemes. The assessment was based on scheme documentation (2008/2009), associated published literature and historical comment. The analysis showed that assurance schemes, generally, do not meet all the desired policy outcomes but this should not necessarily be expected or sought. However, such schemes are ideally placed to help the industry respond to changing demands, by changing or raising the scheme standards.     

Broadacre farm productivity and profitability in south‐western Australia

This paper examines broadacre farm performance in south‐western Australia. This region has experienced pronounced climate variability and volatile commodity prices since the late 1990s. Relationships between productivity and profitability are explored using panel data from 47 farms in the study region. The data are analysed using nonparametric methods. By applying the Fare‐Primont index method, components of farm productivity and profitability are measured over the period 1998–2008. Growth in productivity is found to be the main contributor of profitability. Gains in efficiency and technical change are identified as jointly and similarly important in their contribution to total factor productivity for the farm sample in the region from 1998 to 2008. However, across environments, efficiency gains play an increasingly important role in influencing productivity as growing season rainfall increases. We conclude that R,D&E that delivers further improvement in technical efficiency and technical change is needed to support the profitability of farms across the study region.     

Off‐farm work,technical efficiency,and rice production risk in Taiwan

This article investigates the differences in yield production, production efficiency, and yield risk for farmers both with and without off‐farm work. Using a nationwide survey of rice farmers in Taiwan, we estimate two stochastic production frontier models that accommodate technical inefficiency and production risk simultaneously for farmers both with and without off‐farm work. The stochastic dominance criterion is then applied to compare the differences in the distributions of the estimated technical efficiency and yield risk between groups. The empirical results indicate that these two groups of farmers use resources in different ways, and off‐farm work is not necessarily associated with lower technical efficiency. For farmers in the lower percentiles of the efficiency distribution, those with off‐farm work are more efficient than their counterparts without off‐farm work. In addition, farmers with off‐farm work face higher production risk and this result is robust for the entire distribution.     

Off‐farm employment and reasons for entering farming as determinants of production enterprise selection in US agriculture

In today’s agriculture, farmers consider off‐farm employment and lifestyle goals in complex ways to select production enterprises. Data from USDA’s Agricultural Resource Management Survey were used to examine how off‐farm employment and ‘reasons for entering farming’ influence production enterprise selection in US agriculture. A two‐stage analysis with a multivariate tobit model was used to examine the impact of off‐farm employment as influenced by government farm programme payments, reasons for entering farming, demographics and location on production enterprise selection. Results underscore the impacts of reasons for entering farming and off‐farm employment on production enterprise choice and provide implications for policy development. The study highlights the importance of government farm programme payments in production enterprise selection by US farmers.     

Soil,water and crop management alternatives in rainfed agriculture in the Sahel: an economic analysis

Most agriculture in the Sahel Region is carried out under rainfed conditions where low and uncertain soil moisture levels limit productivity. Improved soil, water and crop management practices are required to reverse the steady decline in per capita food production and sustain output over the long term. Several technological innovations and related farm management practices are evaluated in a case study of a typical farm in Mali. Through use of a soil-water balance model and a whole-farm economic model an optimal mix of these measures is identified. Compared to a base case where no modern inputs are utilized, the combination of animal traction (oxen team), low levels of NPK fertilizer, tied-ridges, traditional long-season food grain crops and early planting was most effective: food grain output was 35% higher than with the traditional base case; soil erosion was reduced by 72%; and even with residual future soil erosion damage capitalized into current income, net farm income was larger by a factor of almost 45.     

Structural and productivity change in US agriculture, 1950–1982

This paper tests whether structural change in US agriculture is an important channel to TFP growth and evaluates the relative impact of (i) public research and education policies, (ii) private R&D and market forces, and (iii) government farm programs on structural change. We specify a structural econometric model, fit it to US state aggregate data, 1953–1982, and use the associated reduced‐form model to perform counter‐factual policy simulations. The findings include: structural change is a channel to TFP growth in both crop and livestock subsector, i.e. specialization, size, and part‐time farming do impact TFP, holding other variables constant. Public R&D and education have been at least as important as private R&D and market forces for changing livestock specialization, farm size, and farmers’ off‐farm work participation over the study period, but private R&D and market forces have been relatively more important for crop specialization. Changes in farm commodity programs had little impact on farm structure over these study period. Overall, we conclude that if public R&D and education policies had been unchanged at their 1950 values over 1950–1982, major structural changes in US agriculture would have occurred anyway. The forces of private R&D and market forces were at work, including a decline in the price of machinery services and agricultural chemicals, relative to the farm wage.     

Resource reallocation and its contribution to productivity growth in Australian broadacre agriculture

This article uses farm survey data to measure the contribution of cross‐farm resource reallocation to industry‐level productivity growth in Australian broadacre agriculture. We show that resource reallocation between farms mainly occurred between incumbent farms and between farms with different productivity growth. Resource reallocation is estimated to account for around half of the industry‐level productivity growth that occurred between 1978 and 2010, and its contribution appears to have increased over time. Moreover, we also show that resource reallocation effects vary across different inputs, partly due to their different mobility. This analysis improves our understanding of how reforms targeting structural adjustment – and the resource reallocation this generates – can influence aggregate productivity growth.     

Harnessing sustainability,resilience and productivity through conservation agriculture: the case of likoti in Lesotho

Subsistence farmers in Lesotho have been able to boost agricultural yields and increase food production by adopting conservation agriculture. The practice, locally known as likoti, also contributes to combating soil erosion and to enhancing fertility. The socio-economic and environmental benefits help poor households to rehabilitate and strengthen their livelihood capital base and ultimately help rural communities to build system resilience in the face of widespread poverty and increasing vulnerability that affect the country. This paper discusses the major advantages associated with the spread of likoti. By drawing on primary data collected by FAO-Lesotho, it enquires into the determinants of adoption, thereby highlighting constraints and options for future up-scaling. The results show that attending appropriate training is a crucial prerequisite for the correct adoption of likoti. However, training is more effective when trainers pursue true participation and when social capital among farmers is stronger. Further important determinants of adoption are the level of education and the economic incentives provided to vulnerable households. Stronger policy and institutional support in all these areas would thus help address the cultural and resource constraints that limit the full potential of likoti to be harnessed and ultimately hinder its further spread throughout the country.     

Productivity and farm size in Australian agriculture: reinvestigating the returns to scale

A positive relationship between farm size and farm productivity is often considered to be largely due to increasing returns to scale in farm production. However, using farm‐level data for the Australian broadacre industry, we found that constant or mildly decreasing returns to scale is the more typical scenario. In this study, the marginal returns to various farm inputs are compared across farms with different sizes. We found that large farms achieved higher productivity by changing production technology rather than increasing scale alone. The results highlight the disparity between ‘returns to scale’ and ‘returns to size’ in the industry, suggesting that productivity improvement among smaller farms can be made through increasing their ability to access advanced technologies, rather than simply expanding their scale.     

Credit constraints and productivity in Peruvian agriculture

This article evaluates the performance of a rural credit market in Peru. We develop a model that shows that collateral requirements imposed by lenders in response to asymmetric information can lead not just to quantity rationing but also to transaction cost rationing and risk rationing. Just like quantity rationing, these two additional forms of nonprice rationing adversely affect farm resource allocation and productivity. We test the insights of the model using a panel data set from Northern Peru. We estimate the returns to productive endowments for constrained and unconstrained households using a switching regression model. We find that, consistent with the theory, productivity is independent of endowments for unconstrained households but is tightly linked to endowments for constrained households. We estimate that credit constraints lower the value of agricultural output in the study region by 26%.     

Values,trust, and management in New Zealand agriculture

This study provides empirical evidence of the link between outlook and practice among farmers, foresters, and growers in New Zealand. Specifically, we use a large, nationally representative survey to assess how foci on production and environmental outcomes influence the adoption of six good management practices aimed at increasing agricultural sustainability. We then show that while environmentally oriented and production-oriented decision-makers are statistically more prepared to take risks, all rural decision-makers are more likely to adopt new technologies and good practices after seeing their relative advantages successfully demonstrated. Next, we show that social and professional networks are small, often limited to five or fewer operators, which begs the question about how the risk-averse operators become informed about good practice. Hence, we ultimately analyse trust in order to identify other credible demonstrators or informants. We find that veterinarians are the most trusted source of information and that government (at all levels) is the least.     

Farm machinery use,off‐farm employment and farm performance in China

We analyse the joint impacts of farm machinery use and off‐farm employment on maize yields and agrochemical expenses from a household survey of 493 farmers in China. Our findings are obtained from an innovative two‐stage econometric procedure that combines a bivariate ordered probit model with an endogeneity‐corrected ordinary least square regression model. The results show that farmers are jointly making decisions to use farm machines and to work off the farm and that these two household activities affect maize yields and agrochemical expenses in different ways. We show that farm machinery use significantly increases both maize yields and agrochemical expenses, while off‐farm employment significantly decreases agrochemical expenses. Our findings highlight the importance of additional machinery use in increasing farm production; the need to account for possible endogeneity in estimation; and the statistical significance of key household characteristics (gender, education, and household size) on overall farm production.