Location: Soil, Water & Air Resources Research2013 Annual Report
1a. Objectives (from AD-416):
The objectives of this project are: 1) use stable carbon isotope analysis to determine the soil carbon sequestration potential of tree planting on marginal or degraded agricultural soils across climatic gradients in the U.S. Great Plains and Russian Central Uplands; 2) quantify the bioenergy potential of the aboveground woody biomass of these plantings for direct combustion, cellulose to ethanol conversion, or pyrolysis to bio-oils; and 3) apply the results of 1) and 2) to estimate the carbon sequestration and bioenergy potential of these systems in both study regions through renovation of existing plantings or new plantings.
1b. Approach (from AD-416):
Sites will be identified in the U.S. Great Plains and Russian Central Uplands where trees have been planted on former agricultural lands. Soil samples will be collected in transects across the tree row and, with tree tissue samples and undisturbed soil samples from native vegetation, will be analyzed using stable carbon isotope analysis. This approach will quantify changes in soil carbon beneath the trees and identify what proportion of the carbon was derived from the trees. Tree height and diameter measurements will be used to estimate the energy equivalent of the standing woody biomass. Using GIS and modeling techniques, the results of the field studies will be extrapolated to the regional scale to estimate the bionergy and carbon sequestration potential of tree planting on marginal agricultural lands.
3. Progress Report:
This project is under National Program 212 Climate Change, Soils and Emissions as it relates to feedstock production for bioenergy and the associated impacts on soil organic carbon storage. The focus of this research is assessing woody biomass production and soil organic carbon storage in windbreaks planted in the Central Russian Uplands and the U.S. Great Plains. This project relates to the Maintain and Enhance Soil Resources priority area of NP 212. The Energy Independence and Security Act (EISA) of 2007 established a Renewable Fuel Standard (RFS) mandating that 136 billion liters of biofuels are to be produced annually in the U.S. by 2022. Of that amount, 60.5 billion liters (44.4%) are to be produced from cellulosic feedstocks. Energy from biomass is an attractive climate change mitigation strategy as, unlike fossil fuels, energy derived from biomass recycles carbon dioxide (CO2) from the atmosphere into fuel and may sequester additional carbon in the soil and/or reduce greenhouse gas production providing additional mitigation benefits. There are extensive tree windbreak plantings already in both the steppes of Russia and in the U.S. Great Plains, which have a significant carbon (C) sequestration potential. The objectives of this project are to: 1) Use stable C isotope analysis to determine the soil C sequestration potential of tree planting on marginal or degraded agricultural soils across climatic gradients in the U.S. Great Plains and Russian Central Uplands; 2) Quantify the C sequestration and bioenergy potential of the aboveground woody biomass of these plantings for direct combustion, cellulose to ethanol conversion, or pyrolysis to bio-oils; and 3) To apply the results of 1) and 2) to use models and spatial analyses to estimate the C sequestration and bioenergy potential of these systems at the regional scale through renovation of existing plantings or establishing new plantings. Soil and plant tissue analyses for samples collected in May and July of 2012 have been analyzed for total, organic, and inorganic C content, total nitrogen content, pH, and particle size distribution. Statistical analyses and interpretation are underway. Preliminary results suggest that soil under agroforestry practices contain more soil organic C than crop fields and undisturbed grasslands. One manuscript on soil profile characteristics has been submitted to a Russian journal. In July of 2013 a second field excursion was completed in the U.S. to study soils with more similar characteristics to the Russian soils. Additional soil profile descriptions and soil samples to 1.2 m were collected and will be analyzed.