Factors explaining the low and variable profitability of fertilizer application to maize in Zambia

It is widely recognized that an “African green revolution” will require greater use of inorganic fertilizers. Often‐made comparisons note that fertilizer use rates in Africa are just 10–20% of those in Asia, Europe and the Americas. Most attempts to explain relatively low‐adoption of fertilizer assume yield responses to inorganic fertilization warrant higher application rates and hypothesize that observed use rates are limited by market‐based factors. Another explanation may be that application rates are low because African yields are less responsive to inorganic fertilizer than yields in other regions, and less responsive than analysts perceive. Examining the case of Zambia, we evaluate whether yield response to fertilizers could explain adoption and application rates. A model of yield response is constructed and a combination of estimators is employed to mitigate potential biases related to correlation between fertilizer use and unobserved heterogeneity as well as stochastic shocks. Results indicate higher fertilization rates would be marginally profitable or unprofitable in many cases given commercial fertilizer and maize prices. Phosphoric fertilizer is particularly unprofitable on acidic soils, which are common in Zambia and other areas of sub‐Saharan Africa. We propose feasible recommendations for diversifying the current government strategy to enhance crop productivity.     

人格特质对茶农有机茶技术采纳的影响

根据福建省安溪县656份的问卷调查数据,基于大五人格特质理论,运用结构方程模型分析人格特质对茶农的有机茶技术采纳行为的影响。结果表明:安溪县茶农的经营特征与其所处的技术环境对有机茶技术采纳行为不存在显著直接效应,但都通过技术采纳态度对技术采纳的行为产生正向影响作用,其中有机茶技术采纳态度起完全中介作用;人格特质对有机茶技术采纳行为既存在直接正向预测作用,又通过有机茶技术采纳态度对技术采纳行为产生间接正向预测作用,并且间接效应大于直接效应,起中介变量的作用。因此,运用人格测评工具来发挥技术采纳者的性格优势在技术采纳过程中的作用,释放有机茶技术的生态溢出效应,将为有机茶技术推广研究提供新思路。     

Achievements and gaps in tef productivity improvement practices in the marginal areas of Northern Ethiopia: implications for future research directions

Tef is the most important crop in Ethiopia and is well-adapted to growing environments, but grain yields are low. The government is therefore promoting the adoption of improved varieties, inorganic fertilizers and new planting techniques. This study gathered information on the use of new agronomic practices and barriers to their adoption through a semi-structured questionnaire administered to 60 farmers or respondents from each of 4 districts of Tigray region in northern Ethiopia viz Laelay-Maichew, Medebay-Zana, Ahferom and Alamata. Data were coded and analysed using SPSS software. Except for animal feed and crop rotation, there were significant differences between districts in the relative importance of several criteria for different uses. Improved varieties were used by the majority of respondents in all districts and fertilizers in all except Alamata where severe moisture stress dictated the choice of variety and reduced fertilizer application. Weed control was mainly by hand except in Alamata where chemical control was common because of the predominance of broad-leaved weeds. Transplanting maximized the yield of tef, but a cost–benefit analysis showed that row sowing was more profitable. The study concluded that new varieties better adapted to the likelihood of reduced rainfall and that respond efficiently to fertilizer inputs need to be developed. Until suitable technologies are available, high labour costs would in part dictate some agronomic practices, even if this led to lower yields.     

Price and quantity endogeneity in demand analysis: evidence from directed acyclic graphs

We propose to use the emerging method of directed graphs to study price/quantity endogeneity issues in empirical demand analysis. The approach is illustrated through the examination of U.S. meat consumption. We find that for two major meat products (beef and poultry), retail prices contemporaneously caused quantities consumed, thus were predetermined. In contrast, the quantity consumed of pork appeared to be predetermined relative to its price.     

Rice demand in Tanzania: an empirical analysis

We investigate the consumer side of the Tanzania rice market with the primary objective of estimating price elasticities of imported and domestically produced rice. Previous studies of the rice market in Tanzania claim that domestic rice is implicitly protected by consumer preference of its perceived better quality. However, rice producers increasingly complain that imported rice adversely impacts the price of domestic rice. Using household consumer survey data, we estimate price and expenditure elasticities of imported rice, domestic rice, and maize to assess their substitutability in the Tanzanian diet. Our results show that Tanzanian consumers have a preference for domestic rice varieties with weak substitutability between domestic and imported rice varieties.     

Adoption and Abandonment of Organic Farming: An Empirical Investigation of the Irish Drystock Sector

There is a considerable literature about the adoption of organic farming. However, possible abandonment of organic farming has received scant attention. Thus, relatively little is known about the exit decisions of farmers. In addition, most studies are based on a static framework where it is not possible to account for changes in farmer decisions over time. This article attempts to fill this gap in the literature by investigating the determinants that affect both adoption and abandonment of organic drystock farming over time. The use of duration analysis allows for the consideration of cross‐sectional and time‐varying factors over the study period from 1981 to 2008. Using this dynamic econometric framework revealed a significant time effect on entry and exit decisions. Overall, the results highlight that where no attempt is made to account for exit decisions and time effects, important information about sustainable farmer decisions may not be taken into consideration.     

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。     

Impact of hybrid rice on input demand and productivity

This paper uses farm-level data collected from a sample of 500 households in Hunan province, China, to analyze the impact of hybrid rice on input demand and productivity. Based on regression analyses, it is found that, compared with conventional modern varieties, hybrid rice uses about 4% less labor inputs, 2% less draft animal services, and 6% more chemical fertilizers. The lesser requirements for labor and draft animal services probably arise from hybrid rice's lower seeding rate. Due to heterosis and high seed costs, the use of F₁ seed is economized to about one-third to one-fourth that of conventional varieties. Therefore, less labor and animal power is needed for seed-bed preparation and transplanting. It is also found that, given the same level of inputs, the yield advantage of hybrid rice over the conventional modern varieties is about 19%. Because of the productivity potential, hybrid rice is a candidate for the second-generation “Green Revolution” in other parts of Asia.     

Adoption of agricultural innovations as a two-stage partial observability process

In this paper, we reconsider the appropriateness of certain statistical analyses in innovation adoption studies and suggest that partial observability models may sometimes be more useful. The proposed models allow for a flexible specification of the process of adoption from one stage to two stages, facilitate the modelling of non‐adopters and remedy the violation of the assumption of full information. An application to the adoption of organic cultivation in Greece demonstrates the relative merits of the proposed analysis.     

发展库区经济 致富一方移民

针对水库移民普遍存在生活水平低等问题，结合茶叶生产广阔的发展前景，提出依靠高校科技力量，发展有机茶生产，将资源优势转化成经济效益，使剩余劳力找到出路，使移民通过发展有机茶生产，提高生活水平。     

Factors influencing the profitability of fertilizer use on maize in Zambia

Fertilizer use remains very low in most of Africa despite widespread agreement that much higher use rates are required for sustained agricultural productivity growth. This study uses longitudinal farm survey data to estimate maize yield response functions in a relatively high-potential zone of Zambia to determine the profitability of fertilizer use under a range of small-farm conditions found within this zone. The theoretical framework used in this study incorporates agronomic principles of the crop growth process. We generalize the asymmetric production models and define a concept of yield scaling factors. The model distinguishes different roles of inputs and non-input factors in crop production. We estimate the effects of conventional production inputs as well as of household characteristics and government programs on maize yield. The results indicate that recommended fertilizer application rates in the two specific years were often unprofitable, given observed price conditions and the yield response to fertilizer. However, there was substantial variability in yield response to fertilizer based upon the rate of application, the timeliness of fertilizer availability, the use of animal draught power during land preparation, and whether the household incurred the death of an adult member in the past three years. These modifying factors, as well as variations in input and output prices due to proximity to roads and markets, substantially affected the profitability of fertilizer use on maize.     

Yield and income effects of rice varieties with tolerance of multiple abiotic stresses: the case of green super rice (GSR) and flooding in the Philippines

With the increasing frequency of extreme climatic events, the new challenge is to develop rice varieties that are tolerant of drought, water submergence, and salinity. There are now new high‐yielding green super rice (GSR) cultivars developed at the International Rice Research Institute with increased tolerance to multiple abiotic stresses. But a clear understanding of the economic benefits of these varieties under farmers’ production environments is not yet fully understood. In this article, we assess the yield and income effects of GSR rice varieties using a two‐year panel data from one province. We use matched samples from a propensity score matching method and a fixed‐effects model within a difference‐in‐difference (DID) framework to estimate the yield effects. The income effects were evaluated using the parameter estimates from the yield/production function model. The results of the ordinary least squares and DID fixed‐effects regressions reveal significant and positive effects of GSR varieties on yield. The most important finding is that the benefits from these varieties are strongly felt when there is flooding. This evidence was not as robust when matched samples were used. However, it is clear that the yield benefits from GSR varieties could improve rice food security and help alleviate poverty in the country.     

The Demand for Organic and Conventional Produce in London,UK: A System Approach

The majority of studies on consumer demand for organic products neglect the presence of non‐organic competitors, ignoring their effect on consumer demand for organics. This article uses a demand system which includes both organic and non‐organic fruits and vegetables, with actual (as opposed to stated) data for household purchases. Estimation of our model provides empirical evidence on the interrelationships between organic and non‐organic products, as the relevant cross‐price elasticities. Own‐price elasticities indicate that organic fruits and vegetables are more price elastic than their non‐organic counterparts, and that lower social class households with children have the most own‐price elastic demand. Cross‐price elasticities indicate relatively strong loyalty to organic products.     

Adoption of organic farming in Germany and Austria: an integrative dynamic investment perspective

Farm‐level adaptation to changing economic environments is often slower than expected. Technological innovations, for instance, are frequently adopted at a later date than the net present value of investment suggests. This can be explained by a model of “investment under uncertainty,” which consistently accounts for uncertainty, sunk costs, and the flexibility of investment timing. Its essential conclusion is that, due to temporal opportunity costs, critical incremental cash flows that trigger investments might be higher than those needed for simple cost recovery. This accounts for an ostensible reluctance to invest (economic hysteresis). In this article, we demonstrate how slow conversion to organic farming in general, and the different rates of conversion in Germany and Austria in particular, can be explained by the new investment theory.     

Estimating consumer willingness to pay for food quality with experimental auctions: the case of yellow versus fortified maize meal in Kenya

Biofortification of maize with provitamin A carotenoids is a new approach to the alleviation of vitamin A deficiencies in Africa. Unfortunately these varieties are yellow or orange, while consumers generally prefer white. Consumer willingness to pay for yellow and fortified maize was compared in experimental auctions in three regions in Kenya. The premium that consumers are willing pay for fortified maize (24%) was higher than the discount they require to buy yellow maize (11%), and in one zone consumers prefer yellow. Yellow color is, therefore, not an impossible obstacle for biofortified maize, although it would clearly be easier to introduce this maize first in regions where yellow maize is currently grown.     

Technology and efficiency in a panel of Italian dairy farms: an SGM restricted cost function approach

This article employs a short‐term specification of the symmetric generalised McFadden (SGM) cost function capable of accommodating quasi‐fixed factors and variable returns. Temporary equilibrium and scale economies are investigated while maintaining the consistency of the estimated model with microeconomic theory and approximation properties. It also makes use of a two‐step procedure to estimate first the technology parameters and then time‐varying efficiency at farm level. No distributional assumptions are required on efficiency as we consider a fixed effect model. A balanced panel of Italian dairy farms during the years from 1980 to 1992 serves as the case study. The results suggest a rigid productive structure during the pre‐ and post‐quota period. Moreover, Italian milk producers are found to exhibit considerable excess capacity and rather low input technical efficiency.     

Feasibility of risk‐based inspections in organic farming: results from a probabilistic model

A risk‐based inspection system might improve the efficiency of the organic farming certification system and ultimately provide a basis for increased competitiveness of this sector. This requires the definition of an effective inspection procedure that allows statistical evaluation of critical risk factors for noncompliance. In this article, we present a study based on data from selected control bodies in five European countries that is aimed at determining the feasibility of risk‐based inspections in the organic sector according to the data that are currently routinely recorded. Bayesian networks are used for identification of the factors that can affect the risk of noncompliance. The results show that previous/concurrent noncompliant behavior explains most of the risk, and that the risk increases with farm size and the complexity of their operations. The data currently recorded by control bodies appear to be insufficient to establish an effective risk‐based approach to these inspections.     

Sustainable urban agriculture and the adoption of composts in Cameroon

The increased importance of urban agriculture in developing countries suggests reconsidering some innovation adoption opportunities and challenges, particularly soil fertility inputs. In sub-Saharan Africa, urban horticulture uses a high level of soil inputs like inorganic fertilizers, while local composts are far less common. Yet, municipal solid wastes provide high quantity of organic matter, a major component of compost. Our study aimed to determine if urban horticulture in sub-Saharan towns can provide incentives for compost adoption among farmers. To this end, we surveyed 242 farmers in Yaoundé, the capital of Cameroon in the Central Province, and in Bafoussam, a city in the West Province. We used an Ordered Logit Model to test four soil input modalities adopted by farmers and ranging from no soil inputs, composts only, composts and inorganic fertilizers, and inorganic fertilizers only. Our results revealed that 36% of farmers adopt an exclusive or mixed use of compost. Inorganic fertilizer expenditures, vegetable production, land ownership, and land distance simultaneously and significantly influence the four soil input alternatives. Urban horticulture provides the prerequisites for compost adoption in sub-Saharan Africa. We suggest several recommendations for implementation of a waste recycling commodity chain dedicated to agriculture.     

Environmental impacts of technological change in Bangladesh agriculture: farmers' perceptions, determinants, and effects on resource allocation decisions

This article measures the impact of modern technology adoption in raising farmers' environmental awareness and the impact of farmers' environmental awareness on resource use by utilizing survey data from 21 villages in three agro‐ecological regions of Bangladesh. The econometric analysis is based on the application of the Tobit model explaining farmers' environmental awareness in the first stage and a profit function examining environmental awareness and resource use relationships in the second stage. Results reveal that the “level” and “duration” of involvement with modern technology raises farmers' environmental awareness, and that farmers' environmental awareness reduces resource use including chemicals. Farmers, who are aware of the adverse environmental impacts of modern agricultural technology, use lower amounts of all inputs in order to avoid further environmental damage. Therefore, efforts to raise farmers' environmental awareness are expected to enhance intangible benefits accruing from a relatively less chemical‐intensive environment.     

Analysing Production Technology and Risk in Organic and Conventional Dutch Arable Farming using Panel Data

This paper compares the production technology and production risk of organic and conventional arable farms in the Netherlands. Just–Pope production functions that explicitly account for output variability are estimated using panel data of Dutch organic and conventional farms. Prior investigation of the data indicates that within variation of output is significantly higher for organic farms, indicating that organic farms face more output variation than conventional farms. The estimation results indicate that in both types of farms, unobserved farm‐specific factors like management skills and soil quality are important in explaining output variability and production risk. The results further indicate that land has the highest elasticity of production for both farm types. Labour and other variable inputs have significant production elasticities in the case of conventional farms and other variable inputs in the case of organic farms. Manure and fertilisers are risk‐increasing inputs on organic farms and risk‐reducing inputs on conventional farms. Other variable inputs and labour are risk increasing on both farm types; capital and land are risk‐reducing inputs.