Sustainability of three apple production systems: Organic, conventional, and integrated.

摘要

Currently, escalating production costs, heavy reliance on nonrenewable resources, reduced biodiversity, water contamination, chemical residues in food, soil degradation, and health risks to farm workers handling pesticides, all bring into question the sustainability of conventional farming systems. Due in part to these concerns, organic farming became one of the fastest growing segments of U.S. agriculture during the 1990s and integrated farming has been successfully adopted on a wide scale in Europe. In 1994, a 1.7-hectare replicated study of organic, conventional, and integrated apple production systems was established in Washington State. The goals of this dissertation are to measure the effects of these systems on soil quality, crop quality, pest interactions, financial performance, energy efficiency, and potential environmental impact. Soil quality under organic and integrated management was significantly higher than that under conventional management during 1998 through 2000. In 2001, soil quality under organic management was higher than that maintained under conventional and integrated management. With the 50 percent price premium above conventional market prices received for organic fruit, the organic system resulted in higher profitability than both the conventional and integrated systems. Price premiums of 12 percent for organic fruit and 2 percent for integrated fruit would have been required for the two systems to match the breakeven point of the conventional system. All three systems supported comparable tree growth and cumulative apple yields for the years 1995 through 1999. Post-harvest fruit quality assessments in 1998 and 1999 revealed that organic fruit were firmer and sweeter than conventional and integrated fruit. Based on an environmental impact rating index, which was used to determine adverse environmental impacts of each management system, the conventional system's impact rating was 6.2 times greater and the integrated system's impact rating was 4.7 times greater than that of the organic system's rating. The energy input/output ratio for the organic system during the six-year study period was 7 percent greater than that for the conventional system and 5 percent greater than that for the integrated system. The data indicate that the organic system ranked first in sustainability, the integrated system second, and the conventional system last.