Adding value to spatially managed inputs by understanding site-specific yield response

Many mechanized crop producers and agribusinesses are fascinated with precision agriculture technology, but adoption has lagged behind the expectations. Among the reasons for slow adoption of precision agriculture technology is that initial users focused excessively on in‐field benefits from variable‐rate fertilizer application using regional average fertilizer recommendations. This article illustrates how greater use of site‐specific crop response information can improve variable rate input application recommendations. Precision agriculture is spatial information technology applied to agriculture. The technologies include global position systems (GPS), geographic information systems (GIS), yield monitoring sensors, and computer controlled within‐field variable rate application (VRA) equipment. Experimentation with these technologies is occurring everywhere there is large scale mechanized agriculture. Commercial use has been greatest in the US, where 43% of farm retailers offered VRA services in 2001. Except for certain high‐value crops like sugar beet, farmer adoption of VRA has been modest. The farm level profitability of VRA continues to be questionable for bulk commodity crops. The theoretical model and illustration presented here suggest that VRA fertilization has not yet reached its profitability potential. Most VKA field trials to date have relied upon existing state‐wide or regional input rate recommendations. Unobserved soil characteristics can potentially interact with an input to make its effect on yield vary site‐specifically within fields. Failure to use site‐specific response functions for VRA applications may lead to a misallocation of inputs just as great as that which results from using uniform applications instead of VRA. Agricultural economists have a long history of estimating output response to input applications. Several have started to develop tools to estimate site‐specific responses from yield monitor and other precision agriculture data. Likewise, agricultural economists have developed an important body of research results on information value based on managing variability—typically in temporal settings. With these tools, a major potential exists to develop further benefits from precision agriculture technologies that permit truly spatially tailored input applications.     

Modelling and Mapping Agricultural Output Values Using Farm Specific Details and Environmental Databases

Ongoing concerns regarding the economic losses associated with the CAP and the negative environmental impacts of present land use have led to calls for land use change and consequent efforts to identify areas which are, from both a financial and social perspective, most appropriate for such conversion. This paper develops and applies an output value modelling methodology in which site-specific biophysical factors are combined with farm level data in order to predict input usage and, subsequently, farm profit. The spatial analytic capabilities of a geographical information system (GIS) are used to combine the variety of data employed to permit analysis of a large study area (the entirety of Wales) and yield models of both the market and shadow value of output from the two principal agricultural sectors of the area: dairying and sheep farming. The GIS is then used to produce readily interpretable maps of these values across the study area. The resulting maps are highly compatible both with value maps of alternative land uses given in the recent literature and with approaches to policy formulation currently under development by a range of UK agencies. Such maps may be used to assist estimation of the extent and location of farming response to land use policy change.     

Technological and policy options for sustainable agricultural intensification in eastern Uganda

This article presents a bio‐economic household model, which has been developed to assess the potential impacts of agricultural intensification efforts on economic and ecological indicators in eastern Uganda. A study region in the Lake Victoria Crescent was selected with comparative advantages for intensive agricultural production: high agricultural potential, high market access, and high population density. However, current production is characterized by low input–output systems revealing a discrepancy between development opportunities and actual development outcomes. Based on a farmer participatory research approach, production methods were introduced in the study region aimed at fostering sustainable agricultural development. Data from two community surveys, two comprehensive household and plot level surveys, and farm‐trial data were used to develop and calibrate bio‐economic models for four representative household types. Model scenarios reveal that farm households in eastern Uganda would not pursue sustainable intensification under current socio‐economic conditions. The market environment has to be improved substantially, i.e., transaction and transportation costs have to be reduced, innovative credit schemes for smallholders have to be introduced, and alternative forms of labor acquisition have to be promoted, to provide sufficient economic incentives for the adoption of environmentally sound production methods. In addition, agricultural service provision needs to be reformed and more agricultural research is needed for new and better‐targeted technologies.     

Modelling socially optimal land allocations for sugar cane growing in North Queensland: a linked mathematical programming and choice modelling study

A modelling framework is developed to determine the joint economic and environmental net benefits of alternative land allocation strategies. Estimates of community preferences for preservation of natural land, derived from a choice modelling study, are used as input to a model of agricultural production in an optimisation framework. The trade-offs between agricultural production and environmental protection are analysed using the sugar industry of the Herbert River district of north Queensland as an example. Spatially-differentiated resource attributes and the opportunity costs of natural land determine the optimal trade-offs between production and conservation for a range of sugar prices.     

Biodiversity Conservation and Productivity in Intensive Agricultural Systems

This paper explores the economic effects of biodiversity loss on marketable agricultural output for intensive agricultural systems, which require an increasing level of artificial capital inputs. A theoretical bio‐economic model is used to derive a hypothesis about the effect of the state of biodiversity on the optimal crop output both in the longer run and in the transitional path towards the steady‐state equilibrium. The hypothesised positive relationship between biodiversity stock and optimal levels of crop output is empirically tested using a stochastic production frontier approach, based on data from a panel of UK specialised cereal farms for the period 1989–2000. The results support the theoretical hypothesis. Increases in biodiversity can lead to a continual outward shift in the output frontier (although at a decreasing rate), controlling for the relevant set of labour and capital inputs. Agricultural transition towards biodiversity conservation may be consistent with an increase in crop output in already biodiversity‐poor modern agricultural landscapes.     

Outdoor recreation in various landscapes: Which site characteristics really matter?

This paper investigates the role played by different site characteristics in influencing people's choice of outdoor recreation destinations. Contrary to prior studies, our experiment accounts for a large diversity of eligible landscapes described using photomontages. We use a discrete choice experiment (DCE) proposing respondents to choose among hypothetical destinations described in terms of eight site characteristics. We study the trade-offs made by various profiles of respondents among those site characteristics, resulting in different destination choices. The DCE attributes are spatially explicit to represent recreational patterns in the form of site quality maps using Geographic Information Systems (GIS). We conclude by stressing implications of this research for tourism and land management policy-making in peri-urban environments. Interestingly, preferences for site characteristics vary significantly with the recreational activities that respondents engage in. Hikers and cyclists preferences should be particularly considered in future planning decisions.     

The impact of the 1999 CAP reforms on the efficiency of the COP sector in Spain

The cereal, oilseeds, and protein crop sector (COP) occupies a prominent position within the European Union's agricultural sector. Within Spain, the COP sector accounts for almost a third of total Agricultural Guidance and Guarantee Fund expenses, and half of the utilized agricultural area (UAA). The COP sector is not only relevant because of its physical and economic magnitude, but also because of the political attention it receives. The Common Agricultural Policy (CAP) reforms that occurred during the 1990s paid special attention to this sector. This article aims to determine the impacts of Agenda 2000 on a sample of Spanish COP farmers' production decisions by using an output-oriented stochastic distance function. The distance function allows for an assessment of the reform-motivated changes on total output, input used, input composition, and crop mix. It also permits an assessment of the impacts of the reform on farms' technical efficiency.
Results show that the reform has shifted the production frontier inward and changed output composition in favor of voluntary set-aside land. With respect to input composition, Agenda 2000 induced a decrease in land, fertilizers, pesticides, and other inputs in favor of labor. In addition, Agenda 2000 has had a negative impact on technical efficiency.     

开发区土地利用对市域社会经济发展有效性分析--以江苏省为例

研究目的:研究江苏省开发区土地利用对市域社会经济发展的有效性.研究方法:利用DEA(Data EnvelopmentAnalysis)数据包络模型,选取输入指标开发区占市域土地面积比重、开发区生产总值指数、开发区地均财政收入指数、开发区地均固定资产投资指数,选取与市域社会经济发展相关指标体系为输出指标.研究结果:(1)区域差异:苏南有效性大于苏中,苏中有效性大于苏北地区;(2)无效原因:以开发区土地比重和开发区地均财政收入指数为主;(3)工业化的联动发展机制趋势尚不明显;(4)江苏省开发区对区域经济社会的发展主要集中表现为对市域生产总值和财政收入的贡献.研究结论:DEA模型分析开发区对市域社会经济发展的有效性具有可行性.     

Determinants, differentiation, and development of short-term marginal costs in dairy production: an empirical analysis for selected regions of the EU

This work provides evidence on the determinants, cost differentiation, and development of short‐term marginal costs of dairy farms in important production regions of the European Union. The empirical study is based on the estimation of multi‐input multi‐output Symmetric Generalized McFadden cost functions using an unbalanced panel data set of the European Farm Accountancy Data Network. The results show considerable regional differences in the impact of the outputs, input prices, and fixed factors on marginal costs. Strong evidence can be found that marginal costs decrease over time and is further underlined by the development of derived regional aggregated short‐term supply curves. Marginal cost elasticities and correlation coefficients validate the hypotheses that a high degree of farm specialization, large milk output, and low milk prices are associated with lower marginal costs. Furthermore, the marginal cost spread in the data sample is analyzed. We show that milk output, milk yield, herd size, labor input, and fodder production can be attributed to significant marginal cost differentiation of farms, whereas for crop and animal output, grassland, stock of other animals, and depreciation only minor differentiation can be found.     

Global food demand,productivity growth,and the scarcity of land and water resources: a spatially explicit mathematical programming approach

In the coming decades, an increasing competition for global land and water resources can be expected, due to rising demand for food and bio‐energy production, biodiversity conservation, and changing production conditions due to climate change. The potential of technological change in agriculture to adapt to these trends is subject to considerable uncertainty. In order to simulate these combined effects in a spatially explicit way, we present a model of agricultural production and its impact on the environment (MAgPIE). MAgPIE is a mathematical programming model covering the most important agricultural crop and livestock production types in 10 economic regions worldwide at a spatial resolution of three by three degrees, i.e., approximately 300 by 300 km at the equator. It takes regional economic conditions as well as spatially explicit data on potential crop yields and land and water constraints into account and derives specific land‐use patterns for each grid cell. Shadow prices for binding constraints can be used to valuate resources for which in many places no markets exist, especially irrigation water. In this article, we describe the model structure and validation. We apply the model to possible future scenarios up to 2055 and derive required rates of technological change (i.e., yield increase) in agricultural production in order to meet future food demand.     

Supply response in Ethiopia: accounting for technical inefficiency

Few empirical studies of supply response using the profit function have accounted for technical inefficiency. Using farm‐level panel data from Ethiopia, this study examines the effect of incorporating technical inefficiency in estimating the supply response of peasant farmers. Two systems of output supply and input demand equations are estimated and compared: the conventional model in which technical efficiency is assumed and another in which technical inefficiency is explicitly incorporated. The model with technical inefficiency is preferred on grounds of theoretical consistency and improved estimates, although model comparison tests are not conclusive. Incorporation of inefficiency generally increases the magnitudes and the statistical significance of own price elasticities, substantially so in the case of fertilizer and fertilizer‐intensive crops, and alters the priority attached to nonprice factors. An important result is that only the specification with inefficiency reveals a significant effect of access to extension services on output. Only this specification finds that output increases with household size, which one expects as the farms in the sample are largely subsistence and producing for own consumption. Furthermore, the results demonstrate that farmers' response to incentives is considerably restricted by inefficiency, suggesting that the traditional model would overstate response by excluding the efficiency variable.     

Imperfect Price Deflation in Production Systems

Numéraire prices that are measured with error create challenges for econometric estimation. A straightforward approach for a model with linear input demands, such as generated from a quadratic normalized profit function, is proposed where the numéraire price is measured with error. Numéraire measurement error is likely because expected output price is measured imperfectly by actual output price. An approach using generalized method of moments is developed to estimate such errors-in-variables (EIV) systems that avoids use of extra-sample data or additional structural specifications. Monte Carlo examination of small sample properties shows promise. Measurement error is statistically significant using aggregate U.S. agricultural data.     

Integrating expert knowledge and quantitative information for mapping cropping systems

Scenarios are accepted as useful tools for assessing economic and environmental impacts of land use changes, for involving stakeholders in environmental issues and thus for decision-making. In most studies involving comparison and evaluation of scenarios, a reference situation from which different scenarios will be developed is defined. When dealing with rural areas, scenarios, and thus reference situation, should not only consider land use but also cropping systems. The usual lack of data concerning cropping system distribution in a given region can be overcome by the use of expert knowledge. In this paper, we present a procedure for the spatial allocation of cropping systems that integrates expert knowledge and quantitative data. The aim of this procedure is to develop a reference situation that makes explicit the link between cropping systems and the factors responsible for their geographical location (location factors).     

Evaluating spatial and temporal variation in agricultural output elasticities in Turkey

This study evaluates spatial variation in the relationship between agricultural output and input use across Turkey. The potential impact of the national agricultural policy reform introduced in 2001 on the spatial variation in agricultural output elasticities across the country was explored. By applying a spatial production function to the province‐level data in 2000 and 2007, spatial heterogeneity in the variance of provincial total factor productivity and the input factor‐output elasticities was identified across the country. Results show that the disparities in agricultural activities and geographic conditions affected return from input factors. Empirical findings from a spatial spillover model also suggest that changes in the input factor‐output elasticities varied significantly across Turkey between 2000 and 2007, after the policy reform. Results suggest that future policy reform that recognizes regional comparative advantage through understanding the geographic heterogeneity of the agricultural sector is important for enhancing Turkey's agricultural output.     

Measuring soil quality dynamics A role for economists, and implications for economic analysis

Measuring soil quality is extremely difficult, yet it has clear economic importance. In particular, there is a great deal of empirical interest in the dynamics of soil quality evolution when land managers respond to policies and other incentives. Yet current methodologies for measuring changes in agricultural land quality are largely static and rely heavily either on incomplete measures such as proxy variables, or ad hoc indexes of selected soil characteristics. Moreover, much empirical work relies on static econometric techniques or simulation models. In this paper, we develop a means to infer soil quality changes from input and output data using a dynamic production function model. Using data from field experiments, we estimate the model in a way that allows the recovery of a dynamic measure of soil quality whose evolution depends on variations in management practices. Our methodology and findings will help provide firmer empirical foundations for analyses of the economic implications of land degradation and the soil quality implications of agricultural policies.     

Spatial dependence in agricultural land prices: does it exist?

Trade-offs arise between spatial dependence and choice of functional form in agricultural land price hedonic models. We discuss these trade-offs and how they can create spurious spatial dependence. Using a land sales dataset with apparent spatial dependence, we implement a semiparametric approach avoiding potential problems with the functional form. The results show that in addition to being nonlinear, the impacts are also characterized by significance thresholds that are difficult to capture in a parametric model. More importantly, we fail to detect any spatial dependence demonstrating that inappropriate functional form can indeed be responsible for finding spatial dependence in hedonic models.     

The political economy of agriculture for development today: the “small versus large” scale debate revisited

The role of agriculture in economic development and the development politics of promoting smallholder versus large‐scale agriculture have both been at the center of a long‐lasting and controversial debate. Using an innovative methodology which combines a value chain approach with input‐output‐analysis, the growth multipliers and productivity of both farm types in Guatemala are analyzed. Results show that smallholder agriculture has the same potential to stimulate output growth as large‐scale agriculture. Smallholder value chains include mainly informal sectors and create more jobs than commercial agriculture. Therefore, a reorientation of agricultural and land policies toward small‐scale food producers and within a comprehensive policy of integrated rural development is not only necessary in terms of social equity but also for boosting economic development.     

Impacts of prices and transactions costs on input usage in a liberalizing economy: evidence from Tanzanian coffee growers

Despite improvements in production incentives, agricultural output in Africa remained sluggish through the 1990s. Low use of purchased inputs may be part of the cause of persistently low productivity in African agriculture. This article analyzes the roles of relative prices and transactions costs in explaining low use of chemical inputs among Tanzanian coffee growers. A sample selection model indicates that output prices exert great influence on input purchases and that both fixed and variable transactions costs affect input use decisions. Travel costs in input and output markets have distinct effects on input usage, implying distinct avenues for interventions to promote more intensive use of agricultural inputs.     

Priority setting for research on aquatic resources: an application of modified economic surplus analysis to natural resource systems

In contrast to research on farming systems, research on natural resource systems seldom applies rigorous priority setting techniques, mainly due to difficulties associated with estimating research impact ex ante for such systems. This article presents a replicable approach to priority setting that addresses these difficulties. Assessment is based on multiple criteria, combining economic surplus analysis with subjective scoring, based on information drawn from a cross‐country survey of expert opinion. The approach is applied to the WorldFish Center, a global agricultural research organization focusing on living aquatic resources, both farmed and wild. The exercise demonstrates the relevance of conventional evaluation techniques to fisheries research based on a practical application of its impact pathways.     

Rural credit and agricultural supply in Brazil

The objective of this study is to determine the financing impact of total expenditure on the use of agriculture inputs (fertilizers, labor, and pesticides), and the output of cotton, rice, beans, corn, soybean, and wheat in Brazil. We study the period 1976–2005. The analysis is based on duality applied to the production theory. The output supplies and conditioned input demands are estimated from a translog multi‐output, multi‐input restricted profit function, where the total production credit is used as proxy of the total expenditure. Farmer expectations with respect to crop prices are incorporated to the estimation based on the quasi‐rational expectation model. The output and input responses to the total expenditure are positive and statistically significant except for cotton, wheat, fertilizer, and pesticides. The short‐run output supply response to own prices is inelastic, except for wheat, which presents elastic response to its price. Acreage has a positive impact on the output supply and it is influenced by land productivity. The main conclusion is that farmers face budget restrictions to purchase inputs, and a government credit program might increase the agricultural supply.