Future, Current, and Past Research
Integrating the temperature sensitivity of biological and chemical soil processes to predict climate-carbon feedbacks
Wageningen University and Research. Coming soon!
Carbon in Hawai'i Tropical Soils
For a year, our research aimed to understand how soil mineralogy influences carbon (C) storage in Hawai’ian tropical soils. Hawaiian soils have unique mineralogy that might determine soil C storage capacity and its distribution into different pools. Our exploratory study encompassed three soil types: poorly and non-crystalline minerals, low activity clays, and high activity clays; and three soil pools: particulate organic matter, mineral associated organic matter, and occluded organic matter. We found that poorly and non-crystalline soils store four times more C than other soils. In all soil types, the majority of C was stored in minerals (65 to 97%). Poorly and non-crystalline soils also stored 25% of C in occluded organic matter, whereas in other soils this pool was less than 2%. Further, we found that the amount of occluded C was positively correlated with the amount of non-crystalline Al and Fe forms. These exploratory analyses suggest that the amount and type of minerals might drive C storage capacity and its distribution into different pools.
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Do cover crops provide a net economic benefit to the farmers or/ and reduce economic risk?
During my master’s degree, we developed a biogeochemical-economic model to understand the interactions between human decision making and biogeochemical cycles. Specifically, we simulated how the use of cover crops can help farmers to minimize economic risk given future climate scenarios. For this project, we used ecological production functions of the provision of ecosystem services and their effects on farmer’s profits. We found that under most climate scenarios, cover crop adoption does not generate a sizable difference in farm net present values (NPVs). However, under frequent extreme droughts, adopting cover crops increased a farm’s NPV by 15%. This difference was explained by higher corn yields in the cover crop treatment, where corn yields were 15% higher under frequent extreme droughts. The biogeochemical-economic model simulation results show that this yield increase was due to an increase in three ecosystem services in the cover crop system: improved soil water storage, soil organic matter accumulation, and N retention. (In prep for publication).
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Using analytical pyrolysis-GC/MS to evaluate the chemistry of environmental samples
In my presentation, I talked about how analytical pyrolysis GC/MS can help us understand the correlations between carbon and environmental variables. Analytical pyrolysis GC/MS is a powerful technique used for investigating structural features of complex macromolecules. In other words, it provides a molecular fingerprint of organic compounds. We observed this fingerprint in our dataset, where the samples that clustered together were either from the same geographic location or type (litter, soil, or litter + soil). Therefore, this technique has the potential to help us identify the chemical structure of soil organic carbon and its relationship to biological processes. At the same time, it can help us to improve models of carbon balance under changing patterns of climate, land use, and other factors. Poster presented at the Summer Research Symposium, University of New Hampshire, 2018 (Download PDF). |
The effect of crop diversity on inorganic N under drought conditions
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To have high productivity, farmers apply fertilizer in their fields. Nitrogen (N) helps plants to grow green and produce food. But plants use less than 50% of this N, and the rest is lost in the environment. Climate change will aggravate this problem because N is highly sensitive to changes in rainfall. We evaluated two forms of nitrogen that are available for plant uptake and are susceptible to be lost through leaching: ammonium (NH4+) and nitrate (NO3-). Samples consisted of four crop rotation and two water regimens treatments. We found that during dry cycles, crop rotation can supply more N than monocultures. Suggesting that crop rotation can increase agroecosystem functions and alleviate the effects of climate change in agricultural systems. Poster presented at the Summer Research Symposium, University of New Hampshire, 2017 (Download PDF).
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Last updated: July, 2022