Agriculture is basically an industry on continuously renewable resources and has been historically an industry with harmonizing the environment. However, under the pressure of population growth and cultivated acreage scarcity, production intensification for high productivity has raised the issues of environmental degradation in an agricultural sector. Environ- mental loading from agricultural production depends on farming technology and site-specific character- istics. Thus, an appropriate approach to solving agro-environmental problems should consider the carrying capacity at both local and regional levels. In order to transform conventional system into an environmentally friendly agricultural system, we need scientific information on materials balance approach to agro-ecosystem.
The materials balance approach provides a method for assessing nutrient surpluses of specific villages or regions, and hence their environmental loads. This approach makes it possible to assess the effect of agri-environmental policy measures on nutrient runoff. The objectives of this study are to analyze materials balance and environmental loading in specific regions and to formulate strategies for accelerating the transformation into environmentally friendly agricultural system based on regionally based agro- environmental management system (RAMS). The objectives could be accomplished through cooperation among related organizations including the Korea Rural Economic Institute (KREI), the National Institute of Agricultural Science and Technology (NIAST), and the Korea Environment Institute (KEI). The analytic model based on RAMS was used to estimate environmental burden in the two county areas such as Hongseong county in Chungnam province and Okcheon county in Chungbook province, respectively.
This study consists of six sections as follows:
In Section 1, the problem statement, previous literature review, and the scope and method of the study are briefly discussed. Section 2 outlines the system innovation model for transforming into environmentally friendly agriculture including basic concepts, model framework, farm decision model, and required policy programs. Section 3 presents theoretical basis, regionally based structure, and analytical methods of materials balance in an agro- ecosystem. In particular, this section suggests the methodology for quantifying the agri-environmental burden of specific sites. Section 4 analyzes and diagnoses environmental burden and carrying capacity in specific watershed areas using regionally-based material balance model. Section 5 suggests strategies for an appropriate management of regional agri-environmental resources such as best management practices, life-cycle assessment, and regionally based natural cycling system. Finally, Section 6 briefly reviews research agenda for the second year of this study.
The regionally based agro-environmental model is based on the first and second law of thermodynamics in a closed system, which addresses the problem of environmental loading in the agro-ecosystem. It involves the various factors influencing nutrients management at different levels. To determine nutrient management and economic performance in existing farming system, a targeted process of developing integrated nutrient management technologies and formulating policy instruments is also described. Further development of the approach is required through inclusion of social disciplines, and extrapolation of results to regional areas.
Balances of the major nutrients including nitrogen, phosphorus, and potassium were calculated by region, using the nutrient balance equation that combines calculations of nutrient flows. Three flows into the farm (chemical fertilizer, organic fertilizer and livestock feeds), four flows out of the farm (farm products, other organic outputs, runoff and leaching, and gaseous losses) and four internal flows (consumption of external feeds, livestock manure, crop residues, and consumption of farm products). Data on fertilizer use, organic materials consumption, yields, and residues management were taken from county statistics and interviews with the farmers. Assumptions on runoff and leaching, deposition, and gaseous losses were made by using empirical relationships from literature data (transfer functions).
Major findings of the study present regionally based nutrients balance situation in the specific sites. Annual environmental loads of nitrogen and phosphorus in Hongseong county in 2001 were estimated at 3,741 ton and 808 ton, respectively. In addition, Okcheon county was estimated to have 291 ton in nitrogen and 169 ton in phosphorus. The results show that the amount of macro- nutrients (i.e., nitrogen, phosphorus, and potassium) based on ingredients are over-supplied 161.9 percent in Hongseong county and 37.8 percent in Okcheon county, respectively. The oversupplied macro-nutrients will affect the agricultural environment of both counties negatively by being discharged and leached to soil, ground and surface water
Based on the evaluation of the results of this case study, several suggestions are offered for managing materials balance in specific sites. The most important thing is to establish best mana- gement practices (BMP) and the natural cycling agricultural system. To minimize the over-supply or losses of plant nutrients from the agricultural system, the input of nutrients to the system needs to be reduced. This can be achieved by increasing the level of recycling within the system. In this study, illustrated examples show that it is possible to conserve the ecosystem and minimize the losses of nitrogen and other plant nutrients through careful recycling within the agro-ecosystem through integration of crop and livestock production. However, to achieve high levels of production and recycling efficiency, there needs to be a right balance between the intensity of livestock production and crop production acreage at local and regional levels. Assuming that these principles are followed, the size of livestock herds (specially for swine and pigs) needs to be significantly decreased in Hongseong county.
Finally, the SWOT (the acronym standing for Strengths, Weakness, Opportunities and Threats) analysis which is a commonly used tool for analyzing internal and external environments, was employed to formulate strategies on the transformation into the environmentally friendly agricultural system. The internal and external factors important to the farmers' future are referred to as strategic factors in this study and they are summarized within the SWOT analysis. The final goal of strategic planning process, where SWOT analysis is conducted in the early stage, is to develop and adopt a strategy resulting in a good harmony between internal and external factors.
This study will be finalized in the 2nd year containing the elaboration of regionally based materials balance model and the in-depth socio-economic analysis.
Researchers: Kim Chang-Gil et al.
E-mail address: changgil@krei.re.kr