Organic apple orchards competitive, sustainable
provided by Washington State University
he first comprehensive study of apple-growing systems provides evidence that there are financial as well as environmental rewards for apple growers who go organic.
The Washington State University study, reported in April 19th issue of the science journal Nature, compared the economic and environmental sustainability of conventional, organic and integrated growing systems.
To be sustainable, a farm must produce adequate yields of high quality, be profitable, protect the environment, conserve resources and be socially responsible, said John Reganold, coauthor of the article.
The organic system was more energy efficient, it was better for the environment, it had better soil quality, its yields were as good as the other systems, it was more profitable and its apples were slightly sweeter and firmer. The bottom line is that organic outperforms the others when you talk about sustainability.
Choices of fertilizers and pesticides are the primary differences in the systems. Conventional crop systems employ synthetic chemical pesticides and fertilizers. Organic systems use composts, manures, and biological pest controls. Weeds are controlled with cover crops, mulching and mechanical methods, including burning. Integrated systems, popular in Europe where growers receive subsidies for integrated fruit, blend elements of each of the other two.
During the past decade, organic production gained new adherents in Washington, which produces nearly half of the nation's apples. The primary attraction has been a price premium that organic fruit has received at packing houses.
The study was conducted by Reganold, a professor of soil science; Preston Andrews, associate professor of horticulture; Herbert Hinman, a Cooperative Extension economist; and Jerry Glover, a graduate student.
The idea and the site for the study were suggested by Andy Dolph, a grower and consultant for Stemilt Growers, Inc., a fruit packing company, in Wenatchee. Four plots of each of the systems were planted with Golden Delicious apples on a four-acre site near the central Washington town of Zillah. The researchers measured the potential impacts of the systems on soil quality, horticultural performance, orchard profitability, environmental quality, and energy efficiency.
Soil quality measurements were made by analyzing physical, chemical and biological soil properties and incorporating the data into a soil quality index. The researchers measured accommodation of water entry and water movement, availability of water, resistance to surface structure degradation and support of fruit quality and productivity.
Largely because of additions of compost and mulch, the soil quality ratings were significantly higher for the integrated and organic systems, according to the researchers.
Measurement of horticultural performance included an assessment of yield, fruit size, tree growth, leaf and fruit mineral contents, fruit maturity and consumer taste preference. There were almost no differences across the systems, except that the organic fruit was generally firmer and slightly sweeter than the integrated and conventional fruit. I don't know how to explain that right now, but it may be due to better nutrient balance in the organic trees, Andrews said.
There's been criticism that organic yields are lower than conventional yields, Reganold said. In general that is true, but not always. This study showed that with apples, organic yields can compare favorably with integrated and conventional systems.
Enterprise budgets were generated each year to calculate net returns from total costs and gross receipts. Receipts for fruit from the integrated system were estimated using prices for conventional fruit, since there is no price premium for integrated fruit in this country.
Receipts for the organic system were estimated using prices for conventionally produced fruit for the first three years, the number of years required to make the transition from conventional to certified organic. The price premium to the grower for each grade of organic fruit in the next three years averaged 50 percent above conventional prices.
All three systems became profitable in the sixth year. The break-even point, the point when cumulative costs meet cumulative returns, was projected to occur nine years after planting for the organic system and 15 and 16 years respectively for the conventional and integrated systems.
Labor, fuels, fertilizers and other energy-related inputs were divided by output yield to obtain an energy efficiency ratio. The output/input ratio for the organic system was seven percent greater than the conventional system and five percent greater than the integrated system, making the organic system the most energy efficient.
The environmental impact was judged using a rating index employed by scientists and growers to determine potential impacts of pesticides and fruit thinners. The total environmental impact of the conventional system was 6.2 times higher than the organic system. The integrated system was 4.7 times higher.
The research was funded primarily by the US Department of Agriculture.