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CONTENTS

RESEARCH

1. Soil Quality and Financial Performance of Bio-dynamic and Conventional Farms in New Zealand.

J.P. Reganold, A.S. Palmer, J.C. Lockhart and A.N. Macgregor

Science. Vol. 260: 344-349. 16 April, 1993.

Bio-dynamic farming practices and systems show promise in mitigating some of the detrimental effects of chemical- dependent, conventional agriculture on the environment. The physical, biological, and chemical soil properties and economic profitability of adjacent, commercial biodynamic and conventional farms (16 total) in New Zealand were compared over a 4 year period . The bio-dynamic farms in the study had better soil quality than the neighbouring conventional farms and were just as financially viable on a per hectare basis.

This research compared the soil properties and financial performance of biodynamic and conventional farming systems over a four-year period (1987 to 1991) on the North Island of New Zealand. The comparisons were made among five pairs and two sets of farms of varying size (16 farms total). A farm pair consisted of two side-by-side farms, one biodynamic and one conventional; a farm set consisted of three adjacent farms, one biodynamic and two conventional. Representative farming enterprises in New Zealand were used: market garden (vegetables), pip fruit (apples and pears), citrus, grain, livestock (sheep and beef) and dairy. The combined data showed that biodynamic farms had better soil quality than the neighboring conventional farms.

Reliable economic data from annual accounts were available for 11 of the 16 farms. Comparisons were made of the financial performance of the biodynamic farms both with that of their conventional neighbours and with that of the average representative conventional farm in each region. In comparing the gross margins of these farms (total farm income per hectare minus operating expenses per hectare), one biodynamic farm was greater, two were lower and two were similar to their conventional neighbors. The biodynamic farms usually had less year-to-year variability in gross margin than did the conventional farms. The biodynamic farms had lower total gross margins (gross margin times the effective enterprise area of each farm) than both their conventional neighbors and most of the conventional farms in the region. This difference was largely due to the smaller size and greater enterprise diversity of the biodynamic farms. Gross margin provides a comparison of financial performance of two farms under different management approaches, while total gross margins show the financial return to each whole farm or to the major farm enterprise.

Table 1. Mean Values of aggregated soils data.
Soil Property	All bio. Farms	All Conv. Farms
Bulk density (Mg/m3)	1.07	1.15*
Penetration resistance (0-20 cm)( MPa)	2.84	3.18*
Carbon (%)	4.84*	4.27
Respiration (1 02/hr/g)	73.7*	55.4
Mineralizable N (mg/kg)	140.0*	105.9
Ratio of mineralizable N to C (mg/g)	2.99*	2.59
Topsoil thickness (cm)	22.8*	20.6
CEC (cmol/kg)	21.5*	19.6
Total N (mg/kg)	4840*	4260
Total P (mg/kg)	1560	1640
Extractable P (mg/kg)	45.7	66.2*
Extractable S (mg/kg)	10.5	21.5*
pH	6.10	6.29*
*p<0.01

Science is a weekly, peer-reviewed journal that publishes significant original scientific research, plus reviews and analyses of current research and science policy. www.sciencemag.org

2. Biodynamic Compost and Field Preparations: Effects on Soil Biological Community

L. Carpenter-Boggs, A. Kennedy, J. Reganold.

Submitted to: Soil Science Society, Journal of
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 1999
Publication Date: January 1, 2000
Citation: Carpenter-Boggs, L., Kennedy, A.C., and Reganold, J.P. Organic and Biodynamic Management: Effects on Soil Biology. Soil Sci. Soc. Amer. J. 64:1651-1659. 2000.

Interpretive Summary: The biodynamic preparations are fermented herbs and minerals, used in very small amounts as additions to compost and as field sprays on biodynamic farms. Although practitioners of biodynamic agriculture claim that the preparations benefit microbial activity and populations, little scientific research has addressed this claim. Effects of the biodynamic preparations on the soil microbial community were investigated in field trials. Four fertilizer options: biodynamic compost, non biodynamic compost, mineral fertilizers, and no fertilizer were tested with and without the biodynamic field sprays. Addition of either type of compost to soil resulted in greater microbial activity and populations. Whether or not the biodynamic compost preparations had been used in the compost had no effect on overall microbial activity of populations. The types of activity and populations, however, were affected by use of the biodynamic preparations. Generally, microbial populations inoculated onto a single carbon source substrate will use increasingly more of the substrate over the course of an incubation. Microbes in soils that received biodynamic compost initially were less able to use some carbon substrates, although after further incubation this difference disappeared. Use of the biodynamic field sprays also affected the microbial population's use of some carbon substrates. The meaning of these effects is not clear, but they suggest that the biodynamic preparations affect soil microbial physiology. This research will impact scientists who study microbial inoculants and volatile chemical signals, farmers who use the biodynamic preparations, farmers who are considering using the preparations, and extension agents who may advise farmers on the use or disuse of the preparations.

Technical Abstract: Biodynamic preparations were investigated in field trials using a 4 x 2 factorial design of fertilizers and field sprays. Four fertilizer options: biodynamic compost, non biodynamic compost, mineral fertilizers, and no fertilizer were tested with and without the biodynamic field sprays. Compost treated with biodynamic preparations 502 through 507 and compost not treated with biodynamic preparations caused similar changes in soil microbial parameters as compared to mineral fertilized or unfertilized plots. Classical microbial parameters of soil quality were affected by presence, but not type, of compost. Composts increased soil microbial biomass, respiration, dehydrogenase activity, readily mineralized soil carbon, earthworm populations and biomass, and qCO2. Functional abilities of microbial communities in soils were affected by type of compost applied. Early utilization of potential carbon substrates was lower in soils receiving biodynamic compost than in soils receiving non biodynamic compost Use of biodynamic field sprays was correlated to higher readily mineralized soil carbon (RMC) and lower dehydrogenase activity per unit RMC in 1995. Biodynamic field sprays also altered the soil community's use of carbon substrates. Biodynamic preparations used in compost and as field sprays affected the soil microbial community.

3. Microbial Parameters after Long-Term Use of Biodynamic and Conventional Management

L. Carpenter-Boggs, A. Kennedy, J. Reganold.

Submitted to: Biology and Fertility of Soils
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 1, 1999
Publication Date: January 1, 2000
Citation: Carpenter-Boggs, L., Reganold, J.P., and Kennedy, A.C. Effects of Biodynamic Preparations on Compost Development. Biological Agriculture and Horticulture 17: 313-328. 2000.

Interpretive Summary: Biodynamic farming systems are increasing in the US and around the globe, but their effects on soil quality have not been fully investigated. Seven pairs of biodynamically and conventionally managed farm fields in British Columbia, Canada, were studied to compare biological parameters of soil quality. Biodynamically managed topsoil gave higher measures of mineralizable carbon and microbial enzymatic activity. Biodynamic and conventional soils also have different microbial community profiles. Biodynamic farms use primarily organic fertilizers (compost), while conventional farms use primarily mineral fertilizers. This difference in fertilizer type could cause changes such as those seen in this study. This research adds to the limited scientific literature comparing biodynamic and conventional management systems' effects on soil quality.

Technical Abstract: Seven pairs of biodynamically and conventionally managed farm fields in British Columbia, Canada, were studied to compare biological parameters of soil quality. Parameters included readily mineralized carbon, microbial biomass, respiration, dehydrogenase activity,and qCO2. Readily mineralized carbon and dehydrogenase activity were greater in biodynamically farmed topsoil than in conventionally farmed topsoil. Fatty acids extracted from soils give a 'fingerprint' of the microbial community. After principal component analysis of fatty acid data, microbial communities in biodynamically farmed soils could be distinguished from microbial communities in conventionally farmed soils.

4. FiBL DOK Trial

Soil Fertility and Biodiversity in Organic Farming

Paul Mäder,^1* Andreas Flie bach,,¹ David Dubois,² Lucie Gunst,² Padruot Fried,² Urs Niggli¹

Science. 31 May 2002: Vol. 296. no. 5573, pp. 1694 – 1697. DOI: 10.1126/science.1071148

An understanding of agro-ecosystems is key to determining effective farming systems. Here we report results from a 21-year study of agronomic and ecological performance of biodynamic, organic, and conventional farming systems in Central Europe . We found crop yields to be 20% lower in the organic systems, although input of fertilizer and energy was reduced by 34 to 53% and pesticide input by 97%. Enhanced soil fertility and higher biodiversity found in organic plots may render these systems less dependent on external inputs.

¹ Research Institute of Organic Agriculture, Ackerstrasse, CH-5070 Frick, Switzerland.
² Swiss Federal Research Station for Agroecology and Agriculture, Reckenholzstrasse 191, CH-8046 Zürich, Switzerland.

Organic Farms Reap Many Benefit
Erik Stokstad

Science. 31 May 2002: Vol. 296. no. 5573, p. 1589.DOI: 10.1126/science.296.5573.1589a

On page 1694, agronomists report the results of the longest and most comprehensive study to date comparing organic and conventional farming, measuring many aspects of crops and soil over 21 years. The bottom line: Organic farms can be nearly as productive as regular farms for some crops, and they leave soils healthier. The study also conclusively demonstrates that for most crops, organic plots are more energy efficient per unit crop.

The bountiful crop yields of the green revolution have fed millions, yet they pose an environmental tradeoff: rich harvests in exchange for polluting pesticides and fertilizers. 

Organic farmers have long touted their methods as a more benign way to nourish the world. But few rigorous studies have looked at the long-term yields and environmental effects of organic farming. Outside of Europe organic farms remain a niche operation relying on premium prices to survive.

Now a report on page 1694 brings encouraging news for organic fans. A team led by agronomists Paul Mäder of the Research Institute of Organic Agriculture in Frick, Switzerland and David Dubois of the Swiss Federal Research Station for Agro-ecology and Agriculture in Zürich, reports the results of the longest and most comprehensive study to date comparing organic and conventional farming, measuring many aspects of crops and soil over 21 years. The bottom line: Organic farms can be nearly as productive as regular farms for some crops, and they leave soils healthier. The study also conclusively demonstrates that for most crops, organic plots are more energy efficient per unit crop.

"This study is as complete a picture as we have from anywhere," says Phil Robertson, an agricultural ecologist at Michigan State University, East Lansing. Agrees soil scientist John Reganold of Washington State University, Pullman : "This gives more credibility to organic systems."
           

The 1.5-hectare trial, started in 1978 near Basel , Switzerland, compares four farming systems. One group of plots mimics conventional farming, treated with chemical pesticides and herbicides and soluble nitrogen for fertilizer. Another models an "integrated" approach that includes manure with conventional techniques. The organic plots use only manure and mechanical weeding, along with plant extracts to control pests. The fourth system is a much less common practice called biodynamic farming that adds unique treatments, such as a variety of herbs added to compost manure.
         

Over 2 decades, the average crop yield was about 20% lower in both kinds of organic fields, a finding on par with previous studies. The best-performing organic crop was winter wheat, which stacked up at about 90% of the conventional harvest. The yields are all the more impressive given that the organic plants received less than half the nutrients given to conventional plots. "To add that much less fertilizer and still get 80% of the conventional yields is outstanding," says Reganold. 
         

Because no synthetic fertilizer had to be produced or applied, growing organic crops also required less energy than conventional crops--up to 56% less energy per unit yield. The team also found evidence that nutrient-cycling microbes are more plentiful and efficient in organic soil, making more nutrients available to plants. According to a microbial diversity assay (which measures the range of bacterial metabolites as a proxy), biodynamic soil ranked higher than organic, which in turn outranked soils in conventional fields.
         

More microbes are known to improve soil structure, and Mäder's team found another benefit: higher yields in organic plots with maximum microbes. Earthworms were up to three times more abundant, and there were twice as many spiders and other pest-eating arthropods. Mäder thinks that these environmental benefits and higher energy efficiency help justify the existing government subsidies for organic farmers in Europe : "I think our research could stimulate governments to encourage this by showing long-term benefits."