Progress 10/01/07 to 09/30/12
Outputs
OUTPUTS: To disseminate information to communities of interest I have given talks and participated in workshops including the following. Soil and Compost Science, Common Ground Fair, Sept. 22, 2012. Maine Organic Farmers and Gardeners Association (MOFGA) Fairground, Unity, ME. Member of panel on soil quality, MOFGA Spring Growth Conference, March 12, 2010, Unity, ME. Soil Organic Matter: Key to Soil Health, Hancock County Master Gardener Training, Ellsworth, ME, Jan. 30, 2009.Organic Matter: Chicken Soup for Your Soil, Maine Garden Day, Central Maine Community College, Auburn, ME, April 12, 2008. Organic Matter: Chicken Soup for Your Soil, Master Gardeners Conference, Univ. of Maine, Oct. 20, 2007. I have given or participated in presentations at scientific and grower meetings, including the following. A. Lannan, M.S. Erich, D. Lambert, S. Tavantzis, R. Larkin, A. Alyokhin. The Effect of Compost Addition on Soil Quality. Graduate Expo, University of Maine, Orono, ME, Apr. 28, 2011. M. Susan Erich, S. Tavantzis, R. Larkin, A. Alyokhin, S. Gross, and E. Bernard. A systems approach for enhancing soil quality and plant health under organic and conventional conditions: Northeastern Branch American Society of Agronomy Meetings. Portland, ME, July 14, 2009. M. Susan Erich, S. Tavantzis, R. Larkin, A. Alyokhin, S. Gross, and E. Bernard. A systems approach for enhancing soil quality and plant health under organic and conventional conditions: Northeast Potato Technology Forum, Bangor, ME, Mar 11, 2009. M. Susan Erich, S. Tavantzis, R. Larkin, S. Gross and A. Alyokhin. Effect of Compost Amendment on Soil Properties in Low and High Organic Matter Soils. Soil Science Society of America Annual Meeting. Houston, TX, Oct. 8, 2008. Erich, M.S., S. Tavantzis, R. Larkin, A. Alyokhin and S. Gross. Compost and Biological Amendments in Potato Systems: Effect on Soil Properties and Fertility. Northeast Potato Technology Forum, Fredricton, N. B., Mar. 12, 2008. S. Erich, S. Tavantzis, J. Gerritsen, E. Sideman, R. Larkin, A. Alyokhin, and J. Jemison. Systems approaches to soil fertility and pest suppression. Agricultural Trade Show, Augusta, ME, Jan. 15, 2008. I have also given guest lectures and demonstrations to high school and college classes, including the following. Soils supporting plant growth, guest lecture/demo in PSE 110, January 18, 2012. Dirt: the Resource, field and laboratory soil exercise for Brewer High School Environmental Science class field trip to University of Maine, Orono, ME, May 18, 2009. Dirt: the Resource, field and laboratory soil exercise for United Technology Center Plant Science class field trip to University of Maine, Orono, ME, May 12, 2009. PARTICIPANTS: I have collaborated with Drs. Zhonqi He and Robert Larkin, USDA-ARS, as well as with Drs. Stellos Tavantzis and Andrei Alyokhin, Department of Biology, University of Maine TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Conventional potato production in cool, humid regions such as Maine is often characterized by soil degradation, high pressure from soilborne plant pathogens, and high inputs of fertilizers and pesticides. Soil degradation can be counteracted by adding organic amendments to soil. Compost is widely recognized to be a beneficial soil conditioner. However, how well compost is able to increase soil aggregation and to supply nitrogen is uncertain. We studied a range of compost types, all produced in Maine, under laboratory and field conditions. Although several composts appeared to help maintain small aggregate stability, none appeared to increase it. Immature composts had the greatest effects on soil properties, but generally are not suitable soil amendments due to possible introduction of phytotoxic compounds. One mature compost, produced using a unique process, both stimulated soil microbial activity and maintained levels of soluble nitrogen in soils. Poultry manure is another organic amendment, produced in Maine,which may be beneficially applied to soils to build organic matter and supply plant nutrients, particularly phosphorus. However amending soils with poultry manure to meet plant need for nitrogen, or disposing of excess manure on soils, may lead to over application of phosphorus and accumulation of phosphorus in solid phases. The reactions of poultry manure phosphorus with soils were examined in laboratory and greenhouse studies. Amending soils with poultry manure increase levels of soluble phosphorus and promoted transformation of mineral-bound phosphorus to soluble phosphorus, which was then available for plant uptake. It is hoped that research-based information on the effects of soil amendments such as compost and manure will help accelerate the use of these amendments on-farm to improve soil quality.
Publications
- Bernard, Edward, Larkin, Robert P., Tavantzis, Stellos, Erich, M. Susan, Alyokhin, Andrei, Sewell, Gary, Lannan, Andrew, and Gross, Serena D. 2012. Compost, Rapeseed Rotation, and Biocontrol Agents Significantly Impact Soil Microbial Communities in Organic and Conventional Potato Production Systems. Applied Soil Ecology, 52:29-41.
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: To increase our understanding of compost characteristics and their ability to support microbial activity in soils, a laboratory incubation study was conducted with seven different composts. All composts were produced in Maine utilizing different feedstocks; two were sampled while immature, while the others are commercially-produced. The composts used were relatively similar in terms of pH and carbon content. The C:N ratios ranged from about 10 to 40. When added to soil, composts at the lower end of the range are likely to increase nitrogen availability due to mineralization while composts at the upper end of the range are likely to decrease nitrogen availability due to immobilization. In the laboratory study the effect of compost amendment on aggregate stability varied between treatments and between the two size classes of aggregates examined. Although several composts appeared to help maintain small aggregate stability, none appeared to increase it. The two immature composts (IB and IP) and compost LA had initial rates of decomposition much higher than the control and other mature composts. Compost LA, while mature, is produced utilizing a unique process in which highly decayed feedstocks are mixed with less decomposed material before being composted under carefully controlled conditions for a relatively short period of time in order to minimize the amount of nitrogen lost. Both the higher level of nitrogen and the possible presence of small amounts of labile carbon in compost LA may explain the relatively high rate of carbon mineralization. Compost CC was very mature and showed little ability to stimulate microbial activity. Observed rates of carbon mineralization were described using a model and were related to levels of water extractable organic carbon. Soils amended with compost IB showed an initial decrease in extractable nitrate and maintained low levels during most of the incubation, probably due to nitrogen immobilization caused by the high rate of microbial activity. No other compost showed as significant a decline in nitrogen availability, and C:N ratio did not predict nitrogen availability. A manuscript describing this data is in preparation. A poster presentation was given: A. Lannan*, M.S. Erich, D. Lambert, S. Tavantzis, R. Larkin, A. Alyokhin. The Effect of Compost Addition on Soil Quality. Graduate Expo, University of Maine, Orono, ME, Apr. 28, 2011. In collaboration with Dr. Zhongqi He, USDA-ARS, and a jointly advised graduate student, several studies were conducted on phosphorus in poultry manure. Poultry manure is an organic amendment, produced in Maine, which may be beneficially applied to soils to build organic matter and supply plant nutrients, particularly phosphorus. However amending soils with poultry manure to meet plant need for nitrogen, may lead to over application of phosphorus. We investigated the effects of poultry manure on phosphorus availability to plants by growing ryegrass in pots in a greenhouse study for 16 weeks. The results demonstrated that phosphorus in poultry manure is fairly readily transformed into soluble phosphorus, which is available for plant uptake. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Conventional potato production in cool, humid regions such as Maine is often characterized by soil degradation, high pressure from soilborne plant pathogens, and high inputs of fertilizers and pesticides. Soil degradation can be counteracted by adding organic amendments to soil. Compost is widely recognized to be a beneficial soil conditioner. However, how well compost is able to increase soil aggregation and to supply nitrogen is uncertain. We studied a range of compost types, all produced in Maine,under laboratory and field conditions. Although several composts appeared to help maintain small aggregate stability, none appeared to increase it. Immature composts had the greatest effects on soil properties, but generally are not suitable soil amendments due to possible introduction of phytotoxic compounds. One mature compost, produced using a unique process, both stimulated soil microbial activity and maintained levels of soluble nitrogen in soils. Poultry manure is another organic amendment, produced in Maine, which may be beneficially applied to soils to build organic matter and supply plant nutrients, particularly phosphorus. However amending soils with poultry manure to meet plant need for nitrogen, or disposing of excess manure on soils, may lead to over application of phosphorus and accumulation of phosphorus in solid phases. The reactions of poultry manure phosphorus with soils were examined in laboratory and greenhouse studies. Amending soils with poultry manure increase levels of soluble phosphorus and promoted transformation of mineral-bound phosphorus to soluble phosphorus, which was then available for plant uptake. It is hoped that research-based information on the effects of soil amendments such as compost and manure will help accelerate the use of these mendments on-farm to improve soil quality.
Publications
- Bernard, Edward, Larkin, Robert P., Tavantzis, Stellos, Erich, M. Susan, Alyokhin, Andrei, Sewell, Gary, Lannan, Andrew, and Gross, Serena D. Compost, Rapeseed Rotation, and Biocontrol Agents Significantly Impact Soil Microbial Communities in Organic and Conventional Potato Production Systems, In Press, 2011. Applied Soil Ecology.
- Erich, M. Susan and Hoskins, Bruce M. 2011. Effects of soil drying on soil pH and nutrient extractability. Communications in Soil Science and Plant Analysis, 42:1167-1176.
- Waldrip, Heidi M. , He, Zhongqi, and Erich, M. Susan. 2011. Effects of poultry manure amendment on phosphorus uptake by ryegrass, soil phosphorus fractions and phosphatase activity. Biology and Fertility of Soils 47:407-418.
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: I was a member of a panel on soil quality, Maine Organic Farmers and Gardeners Association (MOFGA) Spring Growth Conference, March 12, 2010, Unity, ME. The following grant was resubmitted for funding: M. Borisover, T. Ohno, and S. Erich; TITLE: Understanding Organic Matter Composition Effects on Controlling Soil Aggregate Stability: An Excitation-Emission Matrix Fluorescence and Laboratory Investigation; AGENCY: BARD - USA/Israel Binational Agricultural Research; DURATION:010-2013; FUNDING REQUEST:$163,590 (UMaine portion). I submitted a manuscript to the journal Agriculture, Ecosystems, and Environment (Effects of Organic Disease Suppression Strategies on Soil Properties in Organic and Conventionally Managed Potatoes, M. Susan Erich, Stellos Tavantzis, Robert Larkin, Andrei Alyokhin, Andrew Lannana, Serena D. Gross, and Edward Bernard). Another manuscript is being written currently. PARTICIPANTS: Graduate student Andrew Lannan has a laboratory study underway examining effects of different composts on soil properties. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The following are significant results from the Aroostook County field study: Soil properties were very different between the two sites due to significant management differences such as a longer rotation and regular additions of organic amendments at the WP site. Higher levels of organic matter in soils at the WP site resulted in higher levels of water stable aggregates and more available moisture at this site as compared to AF, a difference that could increase potato yield especially in drier years. Yields were higher at WP than AF in 2007, the driest year, and 2008, the lowest yielding year. Environmental conditions in 2009 favored conventional production, and AF had the highest yield that year. Yield variability was reduced in the organic system compared to the conventional system. Compost amendment had minimal effects on soil N or soil aggregation. The effect of compost on aggregation was inconsistent and small. Compost decomposition, and the potential effect of compost on soil properties, was probably limited in our study by lack of uniform compost incorporation into the soil and compost maturity. In general the preceding Brassica crop did not affect the measured soil properties, which was not unexpected. This treatment was included for disease suppression, not potential effects on soil properties. There was no evidence that any of the added microbial biocontrol agents affected soil moisture, soluble C, or soluble N. Soil quality under organic management was significantly higher than under conventional management, and yields were higher in two years out of three. The organic disease suppression strategies examined seem unlikely to have a significant impact on soil quality in conventional systems, at least in the short term.
Publications
- No publications reported this period
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: I have given the following presentations to disseminate results of the project: M. Susan Erich*, S. Tavantzis, R. Larkin, A. Alyokhin, S. Gross, and E. Bernard. A systems approach for enhancing soil quality and plant health under organic and conventional conditions: Northeastern Branch American Society of Agronomy Meetings. Portland, ME, July 14, 2009. M. Susan Erich*, S. Tavantzis, R. Larkin, A. Alyokhin, S. Gross, and E. Bernard. A systems approach for enhancing soil quality and plant health under organic and conventional conditions: Northeast Potato Technology Forum, Bangor, ME, Mar 11, 2009. M. Susan Erich*, S. Tavantzis, R. Larkin, S. Gross and A. Alyokhin. Effect of Compost Amendment on Soil Properties in Low and High Organic Matter Soils. Soil Science Society of America Annual Meeting. Houston, TX, Oct. 8, 2008. PARTICIPANTS: The New England Plant Soil and Water Laboratory provided suport and collaboration on the project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
There are no change-in-action outcomes to report so far. The change-in-knowledge outcome so far is that compost application has not increased soil aggregation. However total carbon, moisture, and aggregation have been notably higher at the organically-managed site as compared to the conventionally-managed site.
Publications
- No publications reported this period
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: The Highmoor compost project soils were sampled and analyzed in 2007; they have been sampled, but not yet analyzed in 2008. Soil solution chemistry for compost amended soils from two Aroostook County sites was determined several times during the 2008 growing season. Soils were sampled for water stable aggregate analysis, but the analysis is not yet completed. PARTICIPANTS: The New England Plant Soil and Water Laboratory provided support and collaboration on this project. One undergraduate student received a University of Maine Work Merit Award to conduct research related to this project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The project is only one year old; there are not yet change-in-action or change-in-condition outcomes to report. The change in knowledge outcome so far is that compost amendment has not caused an increase in soil aggregation. The following presentations disseminated project results: Erich, M.S., S. Tavantzis, R. *Larkin, A. Alyokhin and S. Gross. Compost and Biological Amendments in Potato Systems: Effect on Soil Properties and Fertility. Northeast Potato Technology Forum, Fredricton, N. B., Mar. 12, 2008; S. *Erich, S. Tavantzis, J. Gerritsen, E. Sideman, R. Larkin, A. Alyokhin, and J. Jemison. Systems approaches to soil fertility and pest suppression. Agricultural Trade Show, Augusta, ME, Jan. 15, 2008; M. Susan Erich*, S. Tavantzis, R. Larkin, S. Gross and A. Alyokhin, Effect of Compost Amendment on Soil Properties in Low and High Organic Matter Soils, Soil Science Society of America Annual Meeting, Houston, Texas, Oct. 8, 2008.
Publications
- No publications reported this period
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