Balancing the economic, social and environmental dimensions of agro-ecosystems: An integrated modeling approach

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Abstract

There is an increasing need to view agro-ecosystems and to identify remedial management practices in a holistic way. An integrated model based on the driving force–pressure–state–impact–response approach was developed as a tool to assess the effects of policies for improving decision making for the sustainability of agro-ecosystems. An economic model was linked to a process-based biophysical model by a meta-model. Then, a holistic indicator-based impact assessment system was linked to the integrated model to assess policy instruments. The integrated model was applied in the intensive irrigated wheat–maize cropping system of the North China Plain in which water and nitrogen fertilizer management are known to be critical issues for sustainable resource management. The results show there is a trade-off relationship between economic return and environmental outcome. It was shown that water pricing is a more effective policy instrument for improving the sustainability of agro-ecosystem than increasing the price of nitrogen fertilizer. When the water price is raised to 1.0 Yuan/m3 under a two-tariff system, the sustainability indicators for the irrigation water use efficiency was found to increase from 0.37 to 0.77, groundwater use sustainability increased from 0.05 to 0.60, nitrate leaching increased from 0.48 to 0.55 while the indicators for the farm gross margin, food self-sufficiency, and soil nitrogen balance remain unchanged. The results suggest the modeling approach developed here is very useful for evaluating policy options for complex natural resource management issues.

Introduction

Agriculture contributes 24% of global GDP and provides employment to 1.3 billion people or 22% of the world's population (Smith et al., 2007). It is a critical sector of the world economy. Meanwhile, agriculture is arguably the most important managed ecosystem in the world. As the ways in which agro-ecosystems are managed and evaluated are heavily dependent on human values, the economic and social components of agro-ecosystems have been overemphasized in the past. This has caused malfunctioning (dis-services) of agro-ecosystems like land degradation, greenhouse gases emission, loss of bio-diversity, nitrate leaching to water bodies and depletion of groundwater (Conway, 1985, Dale and Polasky, 2007).

There is an increasing need to view agro-ecosystems and to identify the remedial management practices in a holistic way (Pacini et al., 2004). Since the publication of the Brundtland report, the concept of sustainability has received increasing attention in agricultural research. There would appear to be some consensus that sustainability has three basic features: environmental soundness, economic viability and social acceptability (Dumanski and Pieri, 2000). Pannell and Schilizzi (1999) argue that sustainability indicators are a practical and reasonable vehicle for attempting to deal with the multifaceted nature of the ambiguous term ‘sustainability’. As understanding of the complex relationship between agriculture and environment increases, many indicators of agricultural sustainability, environmental sustainability and the effect of agriculture on natural resources and the environment have been developed (Wei et al., 2007c). However links between sustainability indicators and agricultural management practices on one hand, and economic policies on another hand, are not well defined. As a consequence, farmers, policy makers and administrators do not have enough information to alter management systems according to environmental needs (Ahuja, 2003).

Research of agro-ecosystems requires the use of models—the question is what kind? Models of agricultural systems have been developed and have evolved since the 1960s. Prior to the mid-1980s most of the modeling work focused on individual processes of agricultural systems (e.g. Saeki, 1960, Monteith, 1965). Then some multi-process models which describe the processes within an agro-ecosystem appeared including RZWQM (Ahuja et al., 2000), EPIC (Williams, 1995) and DNDC (Li et al., 1992). When a multi-process model is found not to represent spatial heterogeneity at a regional scale, some spatially referenced models like AGNPS (Young et al., 1987), SWAT (Arnold et al., 1990) and WNMM (Li et al., 2007) have been developed. These models allow users to evaluate alternative practices and scenarios in large agro-ecosystems. However, they do not provide answers to the questions of how farmers’ management behaviour could be changed to introduce new management practices (Wei et al., 2005). To overcome this, a rapidly growing number of research projects are integrating economic and biophysical processes into models (Janssen and van Ittersum, 2007). Some of the more notable integrated models are ECECMOD (Vatn et al., 1999), FASSET (Berntsen et al., 2003) and SAM (Belcher et al., 2004). Most of these integrated models have focused on component parts of the system rather than the agro-ecosystem as an entire unit. Furthermore, many of the studies that advocate a systems approach lack a holistic interpretation of the sustainability of the agro-ecosystem. The environmental impacts that are actually modeled are often limited in number and aggregate in depiction (e.g. only total pesticide use and nitrogen losses are assessed). The omission of many environmental aspects can lead to serious errors in a multi-objective policy-making process and conflicts between different government programs or regulations.

Given this backdrop, the purpose of this paper is to provide an integrated-modeling policy analysis tool for improving the sustainability of agro-ecosystems, in which a holistic impact assessment system is adopted. The intensively cropped ecosystem of the North China Plain is taken as the case study area.

Section snippets

The study area

The North China Plain (NCP) is in north-east China with an area of 350,000 km2 (Fig. 1). It is the largest agricultural zone in China containing 34% of the nation's population, 30% of the irrigated land and 40% of the total grain production. The NCP lies in a semi-arid to semi-humid continental monsoon zone. The average cultivated area per person is 0.095 ha and the average water resource per person is less than 500 m3. Irrigation is applied intensively and extensively and agricultural water use

Base scenario

The status of the wheat–maize agro-ecosystem on the NCP under the biophysical, social and economic context in 2003 is given in Fig. 5. It was found that there were high indices for food self-sufficiency, nutrient balance in soil and greenhouse gases emission in Fengqiu County in the base scenario. The indicator value for farm gross margin was 0.73. There was the moderate sustainability in nitrogen use efficiency, nitrate leaching and irrigation water use efficiency. Finally, the indicator value

Discussion and conclusions

Estimating the effects of a policy measure requires the identification of the causal links between the implementation of the measure and its impact on human activities and the environment. The conceptual framework proposed in this study based on the driving force–pressure–state–impact–response approach can be used to examine those links. An integrated biophysical and economic model can capture the stochastic, interconnective, nonlinear interactions and spatial and temporal differentiation of

Acknowledgements

The authors are indebted to the Australian Centre of International Agricultural Research (ACIAR) (project no: LWR/2003/039) and the Australia-China Special Fund (project no: CH06136) for their financial support.

References (53)

  • Y. Li et al.

    A spatially referenced water and nitrogen management model (WNMM) for irrigated intensive cropping systems in the North China Plain

    Ecological Modelling

    (2007)
  • F. Morari et al.

    An integrated non-point source model-GIS system for selecting criteria of best management practices in the Po Valley, North Italy

    Agriculture, Ecosystems and Environment

    (2004)
  • S. Rahman

    Environmental impacts of modern agricultural technology diffusion in Bangladesh: an analysis of farmers’ perception and their determinants

    Journal of Environmental Management.

    (2003)
  • M.J. Scott et al.

    Future N2O from US agriculture: projecting effects of changing land use, agricultural technology and climate on N2O emission

    Global Environmental Change

    (2002)
  • P. Smith et al.

    Policy and technological constraints to implementation of greenhouse gas mitigation options in agriculture

    Agriculture, Ecosystem & Environment

    (2007)
  • J.J. Stoorvogel et al.

    The tradeoff analysis model: integrated biophysical and economic modelling of agricultural production systems

    Agricultural System

    (2004)
  • Y.P. Wei et al.

    Effectiveness of agricultural water pricing on solving the water shortage of North China Plain

    Journal of Resource Science

    (2007)
  • G.A.A. Wossink et al.

    Environmental-economic policy assessment: a farm economic approach

    Agricultural Systems

    (1992)
  • Y.Q. Xu et al.

    Analysis on groundwater table drawdown by land use and the quest for sustainable water use in the Hebei Plain in China

    Agricultural Water Management

    (2005)
  • W.L. Zhang et al.

    Nitrate pollution of groundwater in northern China

    Agriculture, Ecosystem and Environment

    (1996)
  • L. Zhen et al.

    Three dimensions of sustainability of farming practices in the North China Plain: A case study from Ningjing County of Shandong Province, PR China

    Agriculture, Ecosystem and Environment.

    (2005)
  • Ahuja, L.R., Rojas, K.W., Hanson, J.D., Shaffer, M.J., Ma, L. (Eds.), 2000. Root Zone Water Quality Model: Modelling...
  • J.G. Arnold et al.

    SWRRB: a basin scale simulation model for soil and water resources management

    (1990)
  • D. Chen et al.

    Conservation of water and nitrogen management in the North China Plain—using a GIS based water and nitrogen management model (WNMM) and agricultural decision support tool (ADST)

  • Chinese Academy of Sciences (CAS)

    Summary report of efficient utilisation and management of agricultural resources, a case in Ningjin County

    (2000)
  • Chinese Research group of China Soil Taxonomy System

    China Soil Taxonomy System

    (1995)
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