What determines irrigation efficiency when farmers face extreme weather events? A field survey of the major wheat producing regions in China

Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events. This paper first calculates irrigation efficiency with a translog stochastic frontier production function and then investigates what happens when extreme weather events occur via a Tobit model. The estimated results reveal several important features of irrigation practices: i) irrigation efficiency is lower when extreme weather events occur; ii) large variations in irrigation efficiency occur across irrigation facilities; iii) the farm plots exhibit an extreme distribution across efficiency levels; and iv) water-saving techniques, technology adoption, and the maintenance of farmers’ economic resilience are major determinants of irrigation efficiency. Based on these results we propose the following recommendations: i) farmers should balance crop yield and water use; undertake relevant training programs and adopt water-saving techniques; ii) local governments and researchers should help farmers to find the optimal level of irrigation water use based on their own circumstances and provide better water-saving techniques and training programs rather than simply encouraging farmers to invest in irrigation facilities in the most extreme weather years; and iii) the income level of farm households should be increased so as to improve their resilience to natural disasters.     

Impact of introducing a herb pasture area into a New Zealand sheep and beef hill country farm system: a modeling analysis

New Zealand is well known for export of meat and dairy products from low cost pastoral systems. These farm systems are continually evolving for increased efficiency, in part through the use of metabolic energy modeling tools by farmers and farm consultants to explore alternative farm system configurations and identify new efficiencies. One recent innovation is the introduction of a herb pasture area, such as plantain. We used metabolic energy modeling to quantify seasonal feed flows in two successive years in a New Zealand hill country farm system, and to analyze the impact of the introduction of an area of plantain. Models employed were a self-built Microsoft Excel spreadsheet and a commercial New Zealand farm systems modeling package, FARMAX. Herbage production, animal performance and financial results for a base farm scenario created from the average of survey data for hill farms in the southern North Island, and the same farm with 10% and 20% of the area in plantain for the years 2010–2011 and 2011–2012 were modeled. The self-built model performed similarly to the commercial model. The system configuration of the base farm stockpiles surplus autumn feed for release to animals in winter and also incorporates flexibility that confers resilience to interannual weather variation through varying dates animals are purchased or sold. The introduction of an area of plantain was predicted to increase herbage production, animal performance and financial returns. The predicted benefit was higher for the year 2010–2011 where a drought occurred in summer than for the following year with higher summer rainfall. This demonstrates the profitability of introducing a plantain area to New Zealand hill farm systems, and suggests plantain will assist to mitigate adverse effects of warmer and drier summer conditions associated with current climate change trends.     

Crop Diversification in Coping with Extreme Weather Events in China

Apart from the long-term effects of climate change, the frequency and severity of extreme weather events have been increasing. Given the risks posed by climate change, particularly the changes in extreme weather events, the question of how to adapt to these changes and mitigate their negative impacts has received great attention from policy makers. The overall goals of this study are to examine whether farmers adapt to extreme weather events through crop diversification and which factors influence farmers＇ decisions on crop diversification against extreme weather events in China. To limit the scope of this study, we focus on drought and flood events only. Based on a unique large-scale household survey in nine provinces, this study finds that farmers respond to extreme weather events by increasing crop diversification. Their decision to diversify crops is significantly influenced by their experiences of extreme weather events in the previous year. Such results are understandable because farmers＇ behaviors are normally based on their expectations. Moreover, household characteristics also affect farmers＇ decisions on crop diversification strategy, and their effects differ by farmers＇ age and gender. This paper concludes with several policy implications.     

A flexible approach to managing variability in grain yield and nitrate leaching at within-field to farm scales

We up-scaled the APSIM simulation model of crop growth, water and nitrogen dynamics to interpret and respond to spatial and temporal variations in soil, season and crop performance and improve yield and decrease nitrate leaching. Grain yields, drainage below the maximum root depth and nitrate leaching are strongly governed by interaction of plant available soil water storage capacity (PAWC), seasonal rainfall and nitrogen supply in the water-limited Mediterranean-type environment of Western Australia (WA). APSIM simulates the interaction of these key system parameters and the robustness of its simulations has been rigorously tested with the results of several field experiments covering a range of soil types and seasonal conditions in WA. We used yield maps, soil and weather data for farms at two locations in WA to determine spatial and temporal patterns of grain yield, drainage below the maximum root depth and nitrate leaching under a range of weather, soil and nitrogen management scenarios. On one farm, we up-scaled APSIM simulations across the whole farm using local weather and fertiliser use data and the average PAWC values of soil type polygons. On a 70 ha field on another farm, we used a linear regression of apparent soil electrical conductivity (EC_a) measured by EM38 against PAWC to transform an EC_a map of the field into a high resolution (5 m grid) PAWC map. We then used regressions of simulated yields, drainage below the maximum root depth and nitrate leaching on PAWC to upscale the APSIM simulations for a range of weather and fertiliser management scenarios. This continuous mapping approach overcame the weakness of the soil polygons approach, which assumed uniformity in soil properties and processes within soil type polygons. It identified areas at greatest financial and environmental risks across the field, which required focused management and simulated their response to management interventions. Splitting nitrogen applications increased simulated wheat yields at all sites across the field and decreased nitrate leaching particularly where the water storage capacity of the soil was small. Low water storage capacity resulted in both low wheat yields and large leaching loss. Another management option to decrease leaching may be to grow perennial vegetation that uses more water and loses less by drainage.Paper from the 5th European Conference on Precision Agriculture (5ECPA), Uppsala, Sweden, 2005     

For the love of goats: the advantages of alterity

Small-scale, artisanal livestock production is framed as “other” by conventional livestock producers, and rural communities. This alterity, although not without cost, allows women to be involved as active entrepreneurs and managers in artisanal livestock production and also allows farmers to pursue management strategies with the explicit purpose of enhancing animal welfare. The case study presented here, an artisanal goat dairy farm managed by three women, demonstrates that by embracing feminine care identities, these women carve a space for themselves within livestock production in which they can pursue their own economic and affective goals. Analysis of ethnographic data also demonstrates that farmers’ decision-making regarding animal production is based on both affective and instrumental concerns. If we are to understand and operationalize the affective component of farmer decision making based on the livestock–farmer relationship, we must begin to consider to what extent livestock themselves are social actors.     

Use of a pasture growth model to estimate herbage mass at a paddock scale and assist management on dairy farms

Knowing the amount of herbage mass available on the farm (ideally measured weekly) is an important step in achieving high pasture utilization on pastoral dairy farms in New Zealand, but the information must be used in a timely manner to make efficient management decisions. However, most New Zealand dairy farmers do not measure their pastures regularly. This project aimed to develop a simple alternative, in the form of a prototype software tool (Pasture Growth Simulation Using Smalltalk, PGSUS) to predict herbage mass at an individual paddock level, which reduces (not eliminates) the requirement for physical data collection and provides more information from the measurements taken. The main data requirements are pasture herbage mass for each paddock and grazing or cutting events. A climate-driven pasture simulation model is used to predict herbage mass between intermittent pasture measurements. The pasture model contains certain empirical parameters that are fitted to the observed data for each paddock individually, using all the previous data to “train” the model. PGSUS requires daily weather data, including mean, minimum and maximum air temperature, solar radiation, rain and potential evapotranspiration. Data from the Virtual Climate Station Network (VCSN) from NIWA (National Institute of Water and Atmospheric Research Ltd., New Zealand) are used to drive the model. Preliminary testing was done on two commercial dairy farms, one in the Waikato (North Island) and the other in the Canterbury (South Island) regions of New Zealand. Up to 28 days without measurements, PGSUS estimated herbage mass with correlation of approximately 0.9 and with small bias.     

A SIMPLIFIED PLANKTON BUCKET

The waters of the recent floods in Vermont and Massachusetts reached the haymows of hundreds of barns. Excessive heating set in almost immediately after the flood waters receded, endangering the farm buildings. Observations were made at 13 different farms in the valleys of the Winooski, Lamoille and Mississquoi Rivers. These observations are summarized in the following statements: 1. From half a foot to seventeen feet of the piles were under water. 2. In every pile of wet hay observed some "heating" had taken place, frequently to the point of being considered dangerous. 3. Heat was generated in the bottom layers of the piles and, escaping up through the hay, led to the production of draughts of hot gases or "flues" rising to the surface. 4. The large quantity of moisture carried with the hot gases from the lower layers was condensed on the upper, cooler hay, or in the air above. Many hay piles had been soaked throughout by the falling condensed moisture. 5. While the hot hay was being removed from the barns only one farmer had observed any charred materials. 6. The maximum temperature found (besides one case of fire) was 74 degrees C., though temperatures above 70 degrees were recorded in other places. 7. The most marked evidence of excessive heating was observed (by the farmers) on the second and third days after the recession of the flood waters. 8. One authentic case of "spontaneous" combustion of hay caused by the flood was reported. The outstanding features were: a. The lower two feet of the pile consisted of old hay from the preceding season (1926). b. Covering this lower 2-foot section of old hay was a 6-inch layer of first cutting alfalfa. c. Two feet beneath the top surface of the 42-foot pile was another 6-inch layer of alfalfa (second cutting). d. This hay pile which fired "spontaneously" was the only one containing even a small quantity of alfalfa. The urgent need for extensive research upon the problem of the "spontaneous" heating of farm products was emphasized by the lack of scientific knowledge with which to meet the situation.     

马传贫DNA荧光研究

本文采用了荧光探针——(艹啡)薄啶溴红(Ethidium Bromide,简称 EB)插入核酸双链区,形成一种具有较强荧光效应的络合物方法,对马传贫白细胞 DNA进行了荧光滴定和圆二色谱分析。结果表明:马传贫病毒感染的马白细胞 DNA 含量为正常马白细胞的4倍;正常马、免疫马、传贫马在核物质水平上,三者的空间构象存在差异。这一成果为马传贫早期诊断和区分传贫马与免疫马提供了分子水平上的依据。     

Sharecropping Contract Experience in Delta State,Nigeria

Sharecropping has been an age long practice from ancient times. Some scholars saw the practice as being exploitative of the tenants, yet it is still being practiced. The reasons behind it continual practice need to be unveiled. This study was therefore conducted to examine the sharecropping contract experience in Delta State, Nigeria. The landlords decided to practice sharecropping as a result of emigration of their household members, farm size and cost of labours, some of them gave age and their primary occupation as factors for their decisions to opt for sharecropping arrangement. The yields were shared on the basis of 60% for the landlord to 40% for the tenant. The landlords provided all the equipment and inputs, while the tenant's carried out all the farm operations. They faced the constraints of stress, but were able to cope with them, because of hospitals and health centres nearby. The result of the test of hypothesis confirmed the reasons given for deciding on sharecropping arrangement. It was concluded that sharecropping was not exploitative. It was recommended that the practice of sharecropping should be encouraged and not diversified into other sources of livelihood should do so.     

石油设计单位CAD资源最佳配置模型

针对石油工程设计单位的具体情况，提出了ＣＡＤ资源是佳配置的整数规划模型，并对模型的约束条件及目标函数的含义进行了补充说明，为了求解，结合模型特点，通过分析将原模型转化为线性规划问题，并给出了求解算法，由于计算机性能，价格，可靠性等因素随时间的变化幅度较大，针对价格，折旧年限，计算机出图率，计算机能力利用情况等几个参数的变化进行了敏感性分析。最后，根据模型的求解结果，结合一些石油设计院的实际情况进行     

A “curious blend”: The successful farmer in American farm magazines, 1984–1991

Mass media images offer audiences models for how to perform the social roles they depict. Opinions and other attributes of credible media models may likewise be embraced by audience members seeking to identify with those models. Thus farm magazine narratives about “successful” farmers may encourage readers to model or aspire to featured farmers' production and management techniques and ascribe legitimacy to models' responses to current agricultural issues. However, production of agrarian images in the mass media — including images of farms, farmers, and farmers' values — are inevitably biased such that media representations of successful farmers selectively present objective characteristics in terms of the media's own ideological frameworks, which in turn reflect the dominant ideology of the social relations in which the media are engaged. As a first step in identifying farm magazines' role in creating social models for farmers, this study analyzes articles featuring “successful,” “leading,” or “innovative” farmers in leading agricultural magazines. The featured farmers are categorized according to enterprise characteristics and characterizations of them and their management philosophies. Findings show that farmers in farm magazines have larger than average operations and are portrayed in a way that blends a “farming as business” orientation with more conventional agrarian values but that generally omits non-business aspects of farm life.     

Farmers and researchers: How can collaborative advantages be created in participatory research and technology development?

This article examines differences in the research approaches of farmers and scientists and analyzes how these differences are related to the conditions under which both groups engage in experimental work. Theoretical considerations as well as practical experiences are presented to emphasize the great potential of farmer–researcher collaboration for rural innovation. In the first part of the article, the innovative power of farmer research and experimentation is acknowledged by presenting examples such as crop and animal breeding, development of new production systems, farm equipment, and social innovations. Considering the respective comparative advantages of farmers and scientists, and inspired by theoretical concepts in the fields of knowledge management and innovation processes, we discuss five topics for optimizing the collaboration between farmers and scientists in the field of technological innovation: user orientation, decentralization, informal modes of experimentation, externalization of tacit knowledge, and economic considerations. A better understanding of such issues could help researchers to define their own role in the research process, acknowledge the strengths and weaknesses of their own and farmers’ research approaches, overcome communication gaps, and find creative solutions for problems that typically occur in the process of participatory technology development.     

Machinery selection using expert systems and linear programming

Information on a Farm-level INtelligent Decision Support system, FINDS, is presented. This system is desgined to aid in farm machinery selection through its use and interpretation of a farm management linear program (LP) which has been used in extension workshops to assist farm producers with farm-level decisions. Considerable expertise is required to interpret this farm management LP and it has not been used to its potential because there is a shortage of experts to work with individual producers. FINDS incorporates the expertise needed to use the LP for selecting farm machinery. The goal of FINDS is to help the user find machinery sets that can increase farm profit. The knowledge base of FINDS was structured using IF-THEN rules and LISP functions. With the rules and functions, FINDS automatically runs the LP model, extracts and interprets the relevant output, and recommends farm machinery changes that can increase farm profitability.     

Atmospheric science. Weather forecasting with ensemble methods

Traditional weather forecasting has been built on a foundation of deterministic modeling--start with initial conditions, put them into a supercomputer model, and end up with a prediction about future weather. But as Gneiting and Raftery discuss in their Perspective, a new approach--ensemble forecasting--was introduced in the early 1990s. In this method, up to 100 different computer runs, each with slightly different starting conditions or model assumptions, are combined into a weather forecast. In concert with statistical techniques, ensembles can provide accurate statements about the uncertainty in daily and seasonal forecasting. The challenge now is to improve the modeling, statistical analysis, and visualization technologies for disseminating the ensemble results.     

发达国家化肥减量政策的适用性分析及启示

通过梳理和分析欧盟、美国和日本等代表性国家（地区）化肥减量政策的具体做法、实施效果和适用条件,以期发现化肥减量政策在环境取向制定时的共同规律和一般条件,从而为中国化肥减量政策的制定提供可行的政策建议。研究表明,各个国家（地区）的化肥减量政策各有优缺点且适用条件不同,其中欧盟的命令控制型政策适用于涉及农户少、农业种植类型或农场类型同一的情况,美国的经济激励型政策适用于涉及农户较多、农产品市场体制比较完善、价格形成机制灵敏的情况,日本的公众参与型政策适用于相关农业团体较多、经济实力较强的地区。因此,中国在制定化肥减量政策时,应对各国的政策手段取长补短、综合选择;为此,应从完善农产品价格机制和无公害农产品认证制度和积极培育新型农业经营主体等方面着手,通过市场机制的引导促进环境友好型技术的采纳、通过化散为整确保环境标准的有效执行、通过协同带动和宣传引导提高农民的环境意识,从而保证命令控制型、经济激励型和公众参与型等化肥减量政策的有效实施。     

Visual Programming of Stochastic Weather Generator and Future Applications on Agroecological Study

Based on former studies on weather simulator modules in IPMist laboratory, study on visual programming of stochastic weather generator (VS-WGEN) was continued. In this study, Marlkov Chain,Monte Carlo, Fourier Series, and weak stationary process were used to generate the daily weather data in software Matlab 6.0, with the data input from 40 years' weather data recorded by Beijing Weather Station. The generated data includes daily maximum temperature, minimum temperature, precipitation and solar radiation. It has been verified that the weather data generated by the VS-WGEN were more accurate than that by the old WGEN, when twenty new model parameters were included. VS-WGEN bas wide software applications,such as pest risk analysis, pest forecast and management. It can be implemented in hardware development as well, such as weather control in weather chamber and greenhouse for researches on ecological adaptation of crop varieties to a given location over time and space. Overall, VS-WGEN is a very useful tool for studies on theoretical and applied ecology.     

Spatial analysis of yield monitor data: case studies of on-farm trials and farm management decision making

A 3-year case study was undertaken of how North American farmers use yield monitors for on-farm trials in farm management decision making. Case study methods were used because relatively few farmers quantitatively analyze yield monitor data. At this early research stage, insufficient farm management information about the data was available to ask the right questions in a large-scale survey. In addition to the formal case study of farmers experienced at using yield monitors to collect on-farm trial data, the study evaluated the effect of yield monitor data quality on farm decisions. Two levels of yield data quality included standard output where the default settings of farm-level mapping software were accepted and where filtering of the data was undertaken. Results indicated that yield data quality affects farm management decisions. In addition, farmers receiving a spatial analysis of their on-farm trial data tended to use split-field designs instead of replicated split-planter designs. They were also more confident in their decisions than before participation in the spatial analysis project, and made decisions more quickly.